Fish Oil Causing Depression or Anxiety? Consider Acetylcholine.

March 20, 201510 min read

There is considerable evidence supporting the usage of fish oil for depression. The omega-3 fatty acids within fish oil are capable of increasing activity in the prefrontal cortex, enhancing neurotransmission, and reducing inflammation. Although they can be effective as a standalone treatment for mood disorders (e.g. depression), they are also commonly used with success as an augmentation strategy.

Despite the fact that many people have found fish oil (and omega-3s) to be tremendously beneficial for optimization of brain function, others have discovered that the fish oil exacerbates depression, anxiety, and brain fog. In the event that you are experiencing an increase in depression (or anxiety) from fish oil, there are some factors you’ll want to consider.

Factors to consider before blaming fish oil for worsening depression…

Things to consider before assuming that the fish oil is a direct culprit for the worsening of your condition include: the quality, the omega-3 content, other medications/supplements/drugs that you use, as well as individual factors (e.g. lifestyle, allergies, genetics).

1. Quality of fish oil

Taking low quality fish oil can have a toxic effect on both your brain functioning. You should always strive to take the best fish oil supplement on the market, rather than settling for low quality stuff that you’ll find at a local convenience store. The fish oil you take should be laboratory tested for toxins (PCBs, dioxins, Mercury, etc.), purity, and accuracy of ingredients.

You should never take fish oil that smells fishy as this indicates the possibility of rancidity. Fish oil should be stored out of the sunlight and in a cool environment (e.g. the fridge). If you haven’t properly stored your fish oil, are taking low quality stuff, and haven’t done your research, you are setting yourself up to feel worse. There’s no way to tell if you reacted badly to the “fish oil” or the fact that it was poor quality (e.g. rancid).

2. Omega-3 fatty acid content

Many fish oils contain varying amounts of omega-3 fatty acids (DHA and EPA). Some supplements contain slightly more EPA than DHA, while others are the opposite. Additionally some companies formulate fish oils that contain considerably more of one than the other, and others contain even ratios. Although many consider both DHA and EPA beneficial for brain health and mood, not everyone needs both.

Some people may find that DHA provides the most benefit, while others may conclude that EPA provides superior benefit. Certain formulations are available of 100% DHA and 100% EPA. Consider the amount of each of these omega-3s in your current supplement and realize that the ratio may be responsible for making your depression worse.

3. Other drugs, meds, supplements

If you are taking other drugs (e.g. marijuana, alcohol, etc.), pharmaceutical medications, and/or supplements while simultaneously taking fish oil, it’s difficult to specifically isolate the effect of fish oil. Always consider the fact that a worsening of depression (or anxiety) may be related to the side effects of the other substances that you’re using and/or an interaction that may have occurred between the particular substance and the fish oil.

Many people make the mistake of starting multiple supplements simultaneously, which makes it difficult to know whether: Supplement A or Supplement B is the actual culprit for feeling more depressed. If you’re taking fish oil as a standalone supplement, it will be much easier to conclude that the fish oil specifically worsened your condition rather than pinpointing blame on fish oil while taking a myriad of other substances.

4. Lifestyle

Consider any recent changes to your lifestyle that may have contributed to a worsening of your depression. While fish oil may be the direct culprit, if you recently took up any new activity that affects your brain, that could be the cause as well. For example, if you started taking fish oil and meditating on the same day, you won’t truly be able to determine whether the fish oil or the meditation worsened depression and anxiety.

Additionally if you are under significant stress from work, are dealing with a tough relationship, or going through a drug withdrawal, these are all things that may negatively affect your brain and physiology. Always think about what’s going on in your life before assuming a dietary supplement is to blame.

How Fish Oil May Worsen Depression or Anxiety

People love backing a supplement that has shown clinical promise in treating depression. That said, many of those same people fail to understand that not everyone has a good experience. It is important to realize that just because fish oil helps you doesn’t mean that it’ll help your friend, neighbor, or colleague.

Acetylcholine Theory

Perhaps the primary culprit for the worsening of your depression (or anxiety) as a result of fish oil supplementation is the neurotransmission of acetylcholine. Many researchers believe that supplementation of fish oil tends to increase extracellular levels of acetylcholine, a neurotransmitter involved in processing sensory information, recall memory, vigilance, and learning.

For individuals with abnormally low levels of acetylcholine, fish oil supplements will likely provide tremendous benefit. Chronically low levels of acetylcholine are associated with neurodegenerative diseases and cognitive deficits. However, among those who already have high levels of acetylcholine, (or in those who are sensitive to acetylcholine), fish oil may compound the existing problem.

Just a year ago, scientists discovered that when mice were given an SSRI, the drug increased levels of acetylcholinesterase (an enzyme that breaks down acetylcholine). By increasing acetylcholinesterase, you’ll lower levels of acetylcholine. The scientists speculated that although serotonin increase may help depression, reducing high acetylcholine may also be responsible for some of the antidepressant effect from an SSRI.

If fish oil is elevating your acetylcholine levels and acetylcholinesterase levels are low (or staying the same), you may end up feeling more anxious (and/or depressed) as a result of the supplementation. Those who are sensitive to the effects of fish oil supplements may need to discontinue in hopes that acetylcholine levels naturally decrease.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2775891/

Amines: These are chemicals that are formed in food during the breakdown of amino acids. The most common of food-derived amines is that of histamine, which can cause a variety of unwanted psychiatric symptoms including depression and anxiety. Some people with a sensitivity to salicylate have reported that they aren’t able to tolerate fish oil capsules. It is speculated that they may have an unfavorable reaction to the amines.

Brain activity: It is possible that fish oil enhances homeostatic functioning and changes regional activity within the brain after consistent supplementation. This means your brain may literally re-wire itself in response to the supplement that it’s receiving. In many cases people notice that their cognitive function is enhanced and their mood improves.

However, for others the alteration of regional blood flow may be detrimental to mood and possibly cognitive performance. It should also be hypothesized that brain waves and QEEG patterns may change with continued fish oil supplementation. Although most evidence would suggest that fish oil is highly beneficial in promotion of healthy brain activity, supplement-induced changes may not be optimal for everyone.

Neurotransmitters: It is also important to consider that the fish oil may be affecting levels of other neurotransmitters that could increase levels of depression and/or anxiety. In addition to the aforementioned acetylcholine, other neurotransmitters affected by fish oil include: serotonin, dopamine, and glutamate. Increasing levels of omega-3s may enhance the efficiency by which neurotransmitters are delivered and may elevate levels. Some believe that levels of norepinephrine may be lowered after consistent omega-3 supplementation, but this claim is unverified.

What to do if fish oil makes you depressed…

It makes zero sense to continue supplementing something that makes you feel worse each day. Whenever conducting a supplement trial, you should document your mood and cognition (with some sort of test or chart) pre-trial, and then compare it at various timed checkpoints to determine whether you’ve improved or declined in mood and/or performance. Another couple options you could test include: reduce the dosage and frequency by which you supplement the fish oil, and you could also switch to a formulation with different omega-3 contents.

1. Discontinue

Common sense would suggest that you discontinue from the fish oil if it’s clearly making you feel worse. If may take awhile for you to bounce back to feeling normal after you’ve discontinued the supplement. While the fish oil isn’t going to have a major withdrawal like most antidepressants, your brain may take awhile to readjust to lowering levels of certain neurotransmitters (e.g. acetylcholine) that the fish oil was increasing.

2. Cut back

A second option to consider if you believe that you stand to benefit from omega-3 fatty acids is to simply reduce the dosage that you’re currently taking. High amounts of fish oil are more likely to elicit more significant changes within the brain. More significant changes are likely to occur when the dosage of the fish oil supplement is higher. However, not everyone needs a the same high, recommended dose.

Assuming your fish oil is of good quality, you may simply want to scale back on the quantity that you take. Some people are highly sensitive to the fish oil’s effects and may not need as much as others. In addition to cutting back on the dosage, you could also cut back on the frequency by which you take the fish oil. Instead of supplementing daily, supplement once every few days or with reduced frequency.

3. Alter omega-3 ratios

Some rodent studies suggest that increasing levels of DHA (an omega-3 in fish oil) may be responsible for increasing acetylcholine. If you suspect that the increase in acetylcholine is responsible for your increased depression and/or anxiety, it may be worth testing out a different formulation of fish oil that contains less DHA. There are some companies that make pure EPA (which may be what you’d want to try if you’re more concerned about mood than cognition).

Before jumping to conclusions as to which omega-3 fatty acid is causing the problem, you may want to test each one on for a trial and determine whether you react better to EPA, DHA, or a certain ratio of the two. This is something that most people don’t try, but may eliminate the problem.

Source: http://www.ncbi.nlm.nih.gov/pubmed/9408223

4. Consider L-Tyrosine

Although fish oil-induced depression hasn’t been thoroughly investigated in humans, if you buy into the theory that it may be a direct result of increased acetylcholine, you could possibly offset the effects by supplementing L-Tyrosine. In rodent studies, increasing levels of L-Tyrosine also increased acetylcholinesterase activity, thus helping break down more acetylcholine.

Assuming this has the same effect in humans, the L-Tyrosine would be increasing the amount of acetylcholinesterase, and you’d be lowering your acetylcholine. This may end up improving your mood assuming that it actually increases acetylcholinesterase in humans and that high acetylcholine was responsible for a worsening of your depression (or anxiety) while taking fish oil.

Source: http://www.ncbi.nlm.nih.gov/pubmed/23046746

5. Adjustment Phase

When you start taking any drug or supplement, there may be a phase during which your brain begins adapting to its effects. This is why it takes some people several weeks (or months) before they feel a noticeable difference after they start a supplement. It can take awhile for your brain to accommodate and adapt to the changes.

During the adaptation phase, some individuals may feel temporarily worse, before feeling better. This is a common experience among those who take antidepressants, but lesser reported among those taking supplements. Certain people may want to give fish oil a long trial before automatically assuming that the endgame will result in deep feelings of depression and/or anxiety. It may be worth continuing to supplement with the thought that the cumulative long-term outcome will outweigh short-term discomfort.

Have you experienced a worsening of depression from fish oil?

When any supplement is considered helpful for improving mood, you’ll find many people who have success using it. Then you’ll find some people who can’t really tell if it’s making a difference, and others that swear it’s making them worse. It is important to keep in mind that just because this is a supplement (as opposed to a pharmaceutical drug) does not make it void of potential side effects and adverse reactions.

Many people with high levels of acetylcholine may find that fish oil supplementation makes them feel increasingly depressed, anxious, or moody. Should you experience a “worsening” of your current condition, you probably shouldn’t keep taking fish oil. Just like not everyone responds well to certain drugs, not everyone responds well to certain supplements.

If you noticed that you’ve felt considerably worse from taking fish oil, feel free to share your experience in the comments section below. Be sure to mention how you know it was from the fish oil and not from any other supplements and/or lifestyle changes that you had made at the time. Share what symptoms you experienced, brand of fish oil, and the levels of omega-3s if you can remember – as this will help others get a more accurate understanding of your situation.

Reader discussion (55)

Previously published reader comments are preserved below. New comments are not currently being accepted.

JamesApril 18, 2015
You pose an interesting theory regarding Ach and adverse response. Another theory for the variation of the response with fish oil in the MDD population is perhaps based on inflammatory biomarkers as well as whether it's EPA vs. DHA that's being used. https://bbrfoundation.org/brain-matters-discoveries/omega-3-relieves-depression-symptoms-in-people-with-bodily-inflammation
Brit BergesenJune 3, 2015
I had taken omega 3-6-9 blend flax seed oil for years, then I switched to fish oil and almost immediately had rapid heart rate, insomnia, night sweats, severe anxiety border panic attack, all of which I'd never had my entire life, EVER. I stopped taking the oil and symptoms began to slowly go away over the course of a week, then I began taking my flax seed omegas again and symptoms came back (but not as bad) so I stopped them as well. Could it be my body has just had enough?
GLOOMJune 4, 2015
Hmm... flax isn't generally considered a very bioavailable source of omega-3s... it is poorly converted. Fish oil provides the body with a more potent kick of omega-3s. You could have purchased oxidized, rancid, or low quality fish oil. Or you could just react poorly to the fish oil (e.g. allergic reaction). If you think something's wrong, always consult a medical professional. That said, a good rule of thumb is to avoid over-supplementation. You may want to take a break from any supplemental omegas for several months. The concept or hormesis would suggest that it's best to cycle on and off of various supplements rather than take them daily. And finally, always listen to your body. If a substance is giving you these symptoms, stop taking it for awhile and reassess your situation. Best of luck.
KayJune 30, 2015
Hi I just came across this and am happy I did. 4 years ago I took Evening Primrose Oil supplements and came down with a terrible bout of anxiety and depression when I had previously never experienced it before. I quit it and after a few horrible months it tapered off. I have found myself ever since then very sensitive, in that I guess once the path (anxiety and depression) has been made, it is much easier to find yourself on it again. Anyways, the past few weeks I have been fighting to not travel down that dark path again. I just awoke this morning and realized that I just started supplementing with flaxseed oil a couple of months ago. I am going to stop. This article has been a fantastic help.
KyleAugust 12, 2015
You, I believe, are spot on. I found this site while searching about the effects of choline after noticing that all of the following made my symptoms much more pronounced: ALCAR, Fish Oil, Alpha GPC, and also eating a large quantity of eggs. I am going to try Tyrosine and see if it helps with acetylcholinesterase. I appreciate you making this post, it has really helped me confirm my speculation about this.
JenOctober 22, 2015
About 2 months ago I started doing Crossfit & I decided to become a CF-L1, during our lecture they mentioned taking fish oil because its an anti inflammatory (your muscles get inflamed after a hard workout.) So this part Saturday I was in a CF competition so I thought it would be a great day to start taking my fish oil supplements. Boy, was I WRONG, talk about anxiety, depression and mood swings! Its Thursday and I've been in some kind of funk since Sunday. I've tired listening to music, crafting, the normal feel good things for me and I have not been able to knock it. So my boyfriend asks what wrong with me, I'm like I don't know what the hell is going on, the only thing I've done differently is take fish oil. BINGGGGG, I Google fish oil and depression and it's everywhere that if you have high levels of acetylcholine then you can have these effects. would have been nice to know before hand, but I'd much rather have inflamed muscles and be happy.
HeddyNovember 27, 2015
I have become very sensitive to omega 3. Even from drinking organic milk. I am well into menopause. But when consuming even small amounts of omega 3 in food, my endometriosis flares up and I get very hormonal.
KJBDecember 25, 2015
Marvelously written. Good things to consider.
sicilyJanuary 6, 2016
In menopause depression and anxiety severe and I heard that omega-3 can help depression. I've taken it two different times and each made me more depressed and anxious. I'm anxious and crying off and on... I've not sure if I should take vitamin D then. Anybody know the difference?
TimFebruary 11, 2016
Great article. I have been trying various supplements to help with anxiety, depression and depersonalization disorder. One of them was a fairly high quality fish oil pill, but it didn't seem to help. It's hard to tell though because I was taking some other supplements as well. I do eat a lot of eggs, and I noticed one person commented that eating a lot of eggs sets his symptoms off worse. Anyone else had this experience? I just wanna get back to feeling like me again! Thanks.
LaurieFebruary 28, 2016
I started taking Evening Primrose oil capsules in hopes of improving hair, and after 3 days noticed feeling EXTREMELY depressed. Stop taking and returned to normal. Starting putting about 1/4 cup of ground flax seed on cereal and in about 3 days starting feeling EXTREMELY depressed. Stopped and returned to normal. Started taking fish oil supplements and same thing. Felt EXTREMELY depressed, quit and returned to normal. These supplementation occurred months apart, and I repeated the experiment with them even years apart with the same results. Interestingly, the "feel" of the depression had a particular depression signature. So, the only commonality I guessed was Omega 3, and that my body processed it differently than most. It's frustrating because I want to know why. I have genetically high cholesterol and would love to understand what's going on.
EmmaSeptember 9, 2016
Oh my god this is exactly me! I just told the same story to my husband! I was trying these 3 at 3 separate times for PMS. Bad results every time with all 3 tried at separate times! This week was when I tried flaxseeds every day and I have become depressed and my anxiety is Back, I then realized hang on a minute I was the same when I took EPO or fish oil then found this on Google! So what do we do?
AdrianMarch 12, 2016
I'm pretty sure I have general anxiety but overall its pretty manageable I still am able to function in life. I came across this thread because the last 2 days I've felt overwhelming anxiety to the point where I feel I'm going to have a nervous breakdown. 3 days ago I started taking Fish oil supplement with 750 mg EPA and 250 DHA. Specifically took fish oil in hopes of helping out my mood. The last 2 days my anxiety has increased tremendously and I feel depressed, hard to sleep at night I kept waking up. I can't prove 100% its fish oil but its a pretty big coincidence. Just wanted to share my experience.
Susan StrandMarch 21, 2016
62, athletic, healthy, and small, I have self diagnosed myself as having a negative reaction (nighttime talking head syndrome, moodiness) by taking fish oils of quality, Puritan Pride (Triple Omega 3-6-9), and low dose 1 instead of 3, and a combo blend, or just fish oil. Have experimented over the past few months, and yep, it's the fish oil! My family does have history of allergies, of all sorts, cross reactions, so I'm not surprised when any supplement may cause a reaction. Bottom line, thank you for this article. It gives credence to my own trials and experiments!
AngieApril 21, 2016
I have already been diagnosed that I have an acetylcholine dominance thus taking antidepressants. I was in a great way and was told to take fish oil. I took 2-5 capsules a day because I heard in an online lecture that high levels (750-1500 mg) omega-3, particularly DHA, is the equivalent to a dose of antidepressant. Well, I'm in a bad way... Still. I quit fish oil a week ago but I'm such a mess. How long until I'll get better? I can hardly function some days. I'm so glad I came across this article though. Thank you.
VladimirFebruary 17, 2017
Hey Angie! I hope you have gotten better. I am in the very same situation right now. I took two capsules a day and my sleep (which by any means was not perfect) worsened since day 1 and only got worse within next 4 days (I found this info on the internet and discontinued use on the fourth). It's been 3 nights since and I still haven't got anymore than 3 hours of sleep a night. Can you tell me, have you got through it and how long did it take you? Maybe you used some medicine or supplement that helped you get through it? Will greatly appreciate any help. And thank you in advance!
JenniferApril 28, 2016
I am so glad I found this article. With EVERYTHING touting omegas as a help for depression, it has taken me a long time to realize that my spikes in depression have coincided with taking omegas - and I mean very high grade omegas. This is a relief.
Victor M HogueMay 25, 2016
Soap Box Time... 63, Health Nut since I've been alive. Flax Seed Omega user for years. No adverse reactions ever. Started consistent New Chapter Wild Alaskan Salmon, 1 bottle then 2... then switched to the Hawaiian BIO ASTIN (ASTAXANTHIN) WOW! This took me down hard and for a long time. Quit Cold Turkey... and still had horrible feelings, light headed, mood swings, the blues for months. I only made it through by continuing my life long diet and work out regimen. I would freak out at night, where I would have an anxious feeling coming on, and would hit the door for a power walk. Way too much energy... and this went on for ever...months. Always at night. I finally made it through the fogginess... and today I finally had a good day and feel I'm coming back. A nutritionist I collaborate with, told me, since I was type "O" Blood, I can't handle DHA OR EPA...or anything going straight to my brain. It begins to rewire it. After ETS'D from the Army, I was put on Paxil, Zoloft and others, NOPE! Couldn't handle it. Some people just can supplement their brains. Now, I just eat fish once or twice a week. I find one needs to be careful when supplementing anything. Remember, everything on this living planet need the basics: Sunshine, Water, Stimulation (exercise) Nutrition from good whole food. My feel good pill, work out everyday....and if you engage in a Weight Lifting, it will boost your testosterone... really... without a doubt. Watermelon too. I hate when it' s not in season. Mushy... Men, I promise, if you eat a bowl full every night, WOW. Good Feelings, Good Mood... and Frisky. Then you can rinse your mouth with Warm Water because of the Sugar. Also, massage your testicles for about 1 minute. Really. Remember Stop the Sugar and Whole Grains....it will fire you up all the time... and is simply not good for some people. i.e. If I'm going to take a ride on my horse for 3 days, I usually dry-stall him and feed him lots of good high protein grain, this way he'll be ready to go and endure the ride. Horses can only eat certain kinds of grain and Hay, but Cows can eat pretty much any kind. The Acid in Sudan is not good for horses. Point being, Whole Grains can cause problems in humans too. I.e. upon staying fit, my blood pressure was a little elevated, and I was easily agitated. I ate whole grain and sugar as if it was free, as long as I would keep eating it. I got off, lost 10 lbs of useless fat, and it changed my life. Blood pressure dropped to normal levels, even though it was never really extremely high. Remember my Message to the Brain MTTB... when you're about to drink that Coke, or eat that Candy Bar, "It's only as good, as long, as it goes over your tongue" That's it... if you tell yourself that over and over... you will wean yourself off sweets. My thoughts on supplementing; Sometimes you can over think your condition, and over supplement. Your bodies receptors may not absorb or process each supplement you take, and some supplements may be blocking others, which in turn will be a waste of time and money. Go back to basics. When you were younger, you could eat anything, because your burned it off in an hour. Now that you're older, fuel yourself accordingly. Formula for Life: Sunshine (at least 1-20 mins per day on as much of your body as possible) Fresh Water (A lot) Nutrition, always include protein, and Exercise... Sweat everyday (body's exhaust system). Prayer and Socialization... If you're having withdrawals from a brain supplement, drink lots of water, use a dry sauna to sweat, eat lots of fruits and veggies and keep exercising. It will pass quicker than if you don't. "Exercise is free and you'll never run out of supply." Thank you. I'll be here all week... Vic
JjgMay 11, 2016
Everything people have been reporting: anxiety insomnia, increased depression, and I will add extreme agitation, and waking up in a panic, were things I experienced after two diff types of HIGH quality fish oil after about 2 weeks of each. Same thing with flaxseed oil. I take lexapro which helps, and reading your blog about how SSRIs decrease acetylcholine... now it makes sense why this happened. Now I am afraid to touch anything with omega 3 in it. One thing not mentioned here is DMAE which apparently is found in high amounts in fish oil, which may be why it's doubly devastating, compared to flaxseed oil, at least in my experience.
ToulouseJune 2, 2016
I have been dealing with anxiety for the last 3 months, starting with a few panic attacks. They went away, but still had general anxiety, but was controlling it with CBT and doing well. Two days ago I started taking Fish Oil Omega 3 supplements and coincidentally I have a flare up in anxiety the last two days - back to the high level, near panic. I've taken Omega 3 on and off, sometimes a few days in a row, then not doing it for a month, so the use has been very sporadic. But now I'm wondering if my earlier panic bouts had anything to do with the Omegas. I'll not be taking them and see how it goes.
SimonJune 4, 2016
Thank you for this article. I have tried high quality, mixed DHA/EPA supplements four times over the last three years. I keep a diary and I have noticed a distinct worsening of depression on them every time. I was drawn back (not any more) to fish oil by all of the benefits for inflammation in the scientific literature. In addition to increasing acetylcholine, fish oil also lowers my (already low) BP and hypotension for me, induces a delayed increase in epinephrine, which makes me feel worse. I have similar problems on hypotension with niacin, magnesium, olive leaf oil. Does anyone know if acetylcholine reduces dopamine?
TreeceJune 14, 2016
I have noticed that both fish oil and eggs make my depression get more so. Since fish oil is "supposed" to help depression lesson, I always thought I was making the whole thing up - I didn't believe myself. I would keep going back to using it because it was "supposed" to help. Even though it didn't. Recently I was prescribed estriol cream at a low dose and it really ended up that I became worse depressed. This time I stopped using the cream. I believed my Self. Everyone has their own individual biochemical composition; not one of us is a statistic. Try new things in small amounts, and listen for your own body's symphony. :)
PärJune 15, 2016
I think a big problem is that fish oil becomes rancid when it get's in the body. It's very important to take a stable fish oil like Eskimo Pure 3. I got all side effects by high concentrated fish oil. Heart palpitations, anxiety, etc. - but not by a natural stable unconcentrated fish oil. I am not selling anything.
ChaseJune 28, 2016
Hey, I came here in my search for answers as I've been suffering from anxiety for the past few months. After restricting food items, caffeine, nicotine, I finally decided to cut by my supplements one by one. Not much change. Then the last one, the one I least expected. After three days of stopping Fish Oil supplementation my anxiety was completely gone. It felt like all the static adrenaline had vacated my body, my mind was clear, I could sleep again, I drank coffee without issue, it felt like I had awoken from a dream. To test this I went back on 2x 1200mg Fish Oil caps first thing in the morning and within a few days started to spiral again. I have since stopped supplementing Fish Oil. It's been two days since that test and I already feel the anxious tension and brain fog lifting. We're all wired differently I guess.
KarenJuly 4, 2016
Started taking omega 3 caps at recommendation of optometrist for dry eyes. Also hoped it would decrease joint pain. Am a chronic depression sufferer successfully treated with paxil. Insomnia started within a few weeks of starting omega 3 caps as well as night sweats and agitation. Didn't make the connection and doubled omega 3 dose and increased paxil to reduce insomnia. Increased paxil helped insomnia for a while but soon sleeping problems resumed. Finally realized problem might be omega 3s. Quit cold turkey and now sleeping better but still waking up with brain fog and anxiety after four days of stopping. Hoping it clears soon. Glad I read this and am not alone because believed omega 3 supplementation could only be beneficial. Not for me! Will also watch flaxseed now...
JulieAugust 7, 2016
I started taking it and developed horrible insomnia and agitation.
Donna HelinskiAugust 26, 2016
After taking high amount of Omegavia 500EPA while taking Celexa (SSRI) - My kid had increased anxiety, depression began then Processing &Sensory & Hyperaware and increased to crisis level. Stopped all meds/supplements and began steroid to calm and now a bit better. Do you know how long it takes the Acetylcholine level to correct and will it? Afraid of permanent damage. I cited your webpage to hospital and outpatient PANDAS Doc so they won't blame PANDAS for this new occurrence that I believe is from the fish oil and celexa combo.
JanetAugust 31, 2016
Thank you for such a clearly written article. I bought some Bioglan 2000mg fish oil capsules to treat osteoarthritis. The dosage for "joint health" on the container is 4 capsules per day, a much larger dose than I've ever taken in the past. I have had night sweats, restless legs at night which I usually only get on very hot nights (it's winter now where I am), twitchy legs during the day, extreme anxiety and very low mood, extreme irritability, persistent agitation, couldn't focus on anything, felt deaf as though I were hearing things through ear plugs, etc. I put two and two together by the fourth day (yesterday) and today I feel back to normal. What a nightmare!
BentleyAugust 31, 2016
I have suffered from anxiety and panic attacks for years. My experience has been the opposite. I am on an SSRI and I have noticed that when I exercise and take fish oil things get better. Specifically, it seems to help the effectiveness of the SSRI. Since every post on this site has contained a negative experience between fish oil and cognitive symptoms I hesitated to post this but having dealt with this for years and trying this all very systematically I am confident that fish oil HAS helped me.
mikeSeptember 11, 2016
I was taking a high DHA supplement 800+ and found it caused high anxiety and rapid heart beat/panic attacks...
ValerieSeptember 26, 2016
I purchased Nature Made Omega 3 fish oil 1400 MG and took just one pill an hour before bedtime. Within that hour I experienced a faster heart rate, racing thoughts, body aches, dizziness and a bad headache. I immediately returned the bottle for a full refund the next day. This was 6 days ago and I'm still feeling the anxiety. I was coming out of a depression also with some anxiety. I read online that omega 3 fish oil helps with both anxiety and depression but that definitely was not the case for me.
PalmettoMoonOctober 16, 2016
Just a suggestion. I'm on 40mg of viibryd and would not want to come off of it. Doc said take fish oil for my high cholesterol. I did. Not good. So, I researched and found that a good high quality Hemp oil is a lot better for Omega 3's than any fish oil. It comes in gel cap form just like fish oil. Might work for some and not for others. Depression needs to be researched as much as cancer has non profit organizations. Its a much larger epidemic than cancer and it's not talked about as much because people in general think depression is a thing that's just "all in your head". Total misconception!
RachelNovember 14, 2016
I hope to help others by my experience. I believe myself to have a depressive predisposition. I have the MTHFR A1298c homo variation (23 and me tested). And a couple other detox hindrance markers. Anyways.... I had a baby and reverted back to my depressive worst (that started when I was 16. I am now 41 and have worked VERY hard with diet, exercise, social connections and supplements to get to a good place). But all my coping mechanisms weren't helping and because I was breastfeeding, I had to do everything au natural. What got me out of the hormonal tailspin was l-tyrosine. But I have just discovered and the fish oil may have been exacerbating my symptoms. I have been taking fish oil for 10+ years thinking it was supposed to help. My closest Whole Foods ran out of my normal Nordic Naturals DHA so I bought an EPA heavy one. I was suicidal! I didn't put the connection together until I started sharing the supplement with my husband who is very even keeled. When he got suicidal too - we both stopped immediately. Fish oil can be very dangerous for your mental health. Trust your feelings! And maybe try the tyrosine instead. Take 500-1000mg first thing in the morning when you open your eyes. Wait an hour to eat anything. It also helps with muscle recovery and tiredness. Lord knows - with my second baby, it helped me survive the newborn phase with a smile on my face :)
alexDecember 2, 2016
Hi Rachel. I was just wondering if you went back to the DHA Nordic naturals? I take this one too and have never had problems until I started taking two. I did this for about two weeks (before had only been taking one in the morning) and began to have anxiety/insomnia issues. I then went back to one for about a week but eventually just stopped altogether. I have been off them for about 10 days now. Things are better and I would like to start back at just one a day due to the beneficial effects of the omega 3s... I don't feel like I really get enough at all through plant base foods and I don't really want to eat fish for fear of mercury, etc... I felt good for years on this supplement and just wonder if that increase in dose messed me up and I could start back now since I took a 10 day break. I would only take one and would maybe not even take it everyday.
KatyNovember 20, 2016
Wow, this has been amazing to discover this page. Such helpful suggestions. I've been recently tapering my Sertraline/Zoloft with the aim to come off after about 5 yrs on them. I've overhauled my diet over the last six months and have been feeling fantastic (low carb, high fat, moderate protein = ⬇️30 lbs so far). Anyway, I reduced my Sertraline from 100 to 50 per day over a month with no discernible decline in mood and then last week I started taking good quality fish oil for the DHA... Well. My depression has reared up with a vengeance! Even thinking I'd be better off dead etc, etc. Which I haven't contemplated in a looong time (Zoloft worked very well for me). Anyway, after coming across this page, it's jogged my memory that perhaps Ive come across this reaction before with Evening Primrose Oil and even fish oil at other times... Glad to know there's a bio-chemical reaction going on. I'm going to look further into l-tyrosine and I will cease the fish oil for now...
MaeDecember 22, 2016
So happy to have found this site and I just wanted to add one thing. I am 43 and have been taking Nordic Natural Fish Oil with Vitamin D for years and have had tons of vitamin and mineral testing done over the past 10 years and was always told to take Fish Oil to help with anxiety and depression. Yes it has worked for those 2 things but what I just discovered is that it caused MAJOR brain cloudiness similar to a severe head cold. I secretly thought that I had the early onset of Alzheimer's. I stopped taking it and increased my vitamin C, D & B and feel sooo much better. I have MTHFR like some of the others on this comment section and I wonder if that is the contributing factor. Anyway I think for people with anxiety disorder which I have, increasing Vitamin C, D, & B work wonders. I also get IV drips or Meyer's shots. I have been drug free for 10 years and know that it's never just "one thing" that causes or fixes anything it's always a combination of vitamins, sleep, food, exercise or lack of any of those things that play a role. Anxiety, depression and autoimmune disorders are tricky and they sneak up on you when you and can gradually tear you down. Take care everyone.
ChristinaDecember 31, 2016
I had this exact experience. I have "suffered" from depression for years although I don't like to use the word suffer as I have been successfully treated with antidepressants for many years. I sometimes have a bad day but who doesn't? However, when I started taking fish oil it wasn't long before I started feeling very depressed again even though I was still taking my regular medication. Luckily I suspected the fish oil and stopped taking it. Within a week I was right as rain. Scary stuff!
KristiJanuary 26, 2017
Yes, I also can't tolerate omega oils. I do ok with them for about a week or two and then major anxiety and depression sets in along with fatigue, brain fog, and sleep issues. So grateful for this webpage to help me know I am not alone!!
AdamJanuary 28, 2017
Wow tarted taking fermented cod liver oil and boy oh boy I feel absolutely awful. Anxiety increased 200 per cent. Fatigued. Thanks for sharing the article. The oil has gone straight in my bin. I feel like I'm going loopy.
VictorineFebruary 7, 2017
Hi, this is interesting as my son has Schizophrenia and was prescribed good quality fish oil (Maxepa) by a doctor. I found it had an adverse effect and discontinued within a few weeks as it caused him depression which he never had or has. Though it may work for someone else with the same condition or even at different times. I couldn't take Evening Oil Primrose in my 30's but is a Godsend now!
JulieFebruary 9, 2017
Last December I started taking pure EPA omega-3 1000 mg capsules. The dose is one capsule twice daily. I started off taking this recommended dose, and quickly lowered it to one capsule per day, and then had to stop taking them due to unbearably worsened anxiety, depression and insomnia. I had taken a total of seven capsules. I have had depression, anxiety and insomnia all my life since the age of eight, and I am now nearly sixty. Nothing has ever had the slightest beneficial effect. I remember a few years ago trying 5HTP and it had the same effect of making my symptoms a lot worse, and I had to stop taking it. I don't feel that I want to bother trying L-Tyrosine; I did look it up and there are comments that it can make everything worse and contradictory comments about whether it increases or decreases norepinephrine. Probably another expensive waste of money likely to make me feel worse not better, and I don't have much money and prefer to spend it on nice yogurt, soya and cheese to supply Tyrosine rather than yet another supplement.
SarahMarch 11, 2017
My doctor recommended a fish oil to go along with my other medications. After a week I felt bad. Each morning I dreaded waking up. Three weeks later I'm stopping it. Hopefully it won't be long before the depression lifts.
Gerianne KodyMarch 26, 2017
So true that Omegas (among other things I try) cause me worsening depression! My family just gets quiet when I try to tell them this. Point is - I know my own reaction! I'm happier without!
BethJanuary 2, 2018
I am a 63 year old female with overall good health. I have been taking Nordic Naturals fish oil for several years for joint inflammation from osteo arthritis and dry skin. I have struggled with anxiety and insomnia for years, thinking it was related to menopause. I have also noticed that fish oil was problematic. If I took it with my dinner meal, I would not be able to fall asleep at bedtime, so I started taking it at noon. Two weeks ago I took a higher Nordic Natural DHA formulation for a few days and my insomnia got worse. Waking several times throughout the night and having difficulty going back to sleep. I stopped taking fish oil one week ago entirely and am now sleeping like a rock. I also have been able to successfully decrease the dose of Premarin without exacerbating the insomnia. I had been operating under the assumption that I needed Premarin to help with insomnia. I may be wrong about that. Now I am hoping I can get off Premarin eventually and I will get my fish oil from fish.
GORETTIAJanuary 17, 2018
My eye doctor recommended eye drops with omega 3 for dry eyes. I noticed each time I used them I got agitated, depressed, and very down. I have only used about 6 times... but am gonna quit immediately. I haven't done anything else differently so I think it is connected to the omega 3. It also happened a few years ago when I tried an omega 3 supplement, that is why I made the connection... obviously not for me.
tamaraFebruary 11, 2018
I currently am on leave of absence from work. I take a giant tablespoon of fish oil every morning upon waking with my coffee. Was mostly taking it for my bowels, but wow! After reading this and being a lifelong sufferer of depression... I will stop it and see what happens!! Will update in a few weeks!
David MooreFebruary 21, 2018
I just started taking Krill Oil and I found my levels of anxiety to be increased quite badly. I wasn’t sure why it suddenly reared it’s head again, but it tied in with starting supplementation. I’m going to try going in at half the dose and finish the bottle and see how I feel.
KerryMarch 11, 2018
I googled to see if there was a link to depression and fish oil and found this forum. So thank you - it confirms my suspicions. I have been taking a high quality fish oil, the bottle says 6 capsules per day and they are 1050mg each. I have had a foggy head and felt very down, maybe depressed, I believe since I have been taking it, over 3 months. I didn't make a connection until recently, as I thought it may be due to other circumstances. I have felt constantly weepy too, and very tired and lethargic. I thought a lot about how death would be better than living, although not suicidal. However, it has helped so much with my periods that I thought it was doing my body good. I have had no period pain since I began taking them. I shall stop now, and look for an alternative.
MichaelMarch 26, 2018
A few days ago I tried the Carlson brand of Fish oil (Super Omega-3) and within about an hour I experienced an episode of anxiety which now after reading this article I associate with the product. However, are there any fish oil supplements that do not cause increased anxiety? The supplement I was on had Anchovy, Sardine & Mackerel in it, but perhaps salmon fish oil or another type of fish wouldn't cause anxiety? Any recommendations?
DumitruMarch 27, 2018
I think some may try Omega 3-6-9 instead of just Omega 3 fish oil. I read somewhere that it may not have that bad of effects, that is up to you to try, but I haven't. I tried krill oil 2 years after and same thing, brings anxiety. What works for me is vitamin D. I started with 1 gram (1000mcg) and now taking 2 grams(2000mcg) daily. I would take more but I have one sensitive kidney, which if I take more than 2 grams I can feel it. I also combine it with some tanning here and there, but better is if you can get it from the sun. The way our body produces it from the sunshine is much better than taking the pill, and it can produce it in much higher quantities.
AlissaJuly 11, 2018
Every time I try to take an omega 3 supplement I get extremely depressed and anxious. I will even start waking up with panic attacks! I wish I could take them because they help keep other inflammatory issues that I have at bay. :(
SaraAugust 14, 2018
I went through a major anxiety and OCD that started six months into pregnancy and went on for two years postpartum after my first child. Through the pregnancy and during breastfeeding I was taking different fish oil supplements. I was in a constant state of panic for two years. My brain would get "stuck" on a fearful thought and I'd obsess and obsess in a state of extreme fear. I changed some things in my diet, tried different supplements and managed to start to feel better. At some point I also stopped taking all fish oil. I wish I kept better records but I think I was feeling at least a little better before I stopped taking the fish oil. Fast forward many months later, I thought I was probably getting deficient on omegas, so I started a good quality cod liver oil. Within a couple weeks I was back in the depths of fear and OCD. It took me a few days to realize that it was the cod liver oil. I stopped the supplement completely and it took about a month to recoup... to get my brain back and for the fear to subside. I did get back to normal (for me) which was mild anxiety. So needless to say, I did not start another omega supplement for quite some time. But being the health nut that I am, I knew my body needed omegas. I started eating some wild caught salmon on occasion and felt great eating it. It felt like I was really giving my body something it needed. I then found out I have elevated levels of mercury and that eating any fish for me is probably not a good idea. I also have the MTHFR mutation and my body really doesn't detox well. So I gave up eating salmon. I then was reading about krill and how it's in a phospholipid bound state and how that is different from other fish oils which are in a triglyceride form. I was curious if my body might appreciate the difference and be able to handle it. So I started taking Mercola's krill oil for women, which also has a little evening primrose oil. I've been taking that for many months now and I haven't had any anxiety or OCD issues. In fact, my brain feels BETTER than it has since before pregnancy. I realized that some of the issue with me is that I am super sensitive to glutamates. I had been taking a powdered gelatin daily and during that time the anxiety and OCD were astronomical. When I eliminated the gelatin and also all other possible sources of free glutamates and MSG, my brain calmed down within about a week. It was a blessing, for sure. And when I flub up and eat something (usually out at a restaurant) that has questionable ingredients, I can tell by the next morning because my brain literally feels like it speeds up. The thoughts come rapidly and the fear and panic just hang heavy on me. It takes about a week after an exposure to glutamates for my brain to feel better. So in this article above it mentions this: "Neurotransmitters: It is also important to consider that the fish oil may be affecting levels of other neurotransmitters that could increase levels of depression and/or anxiety. In addition to the aforementioned acetylcholine, other neurotransmitters affected by fish oil include: serotonin, dopamine, and glutamate. Increasing levels of omega-3s may enhance the efficiency by which neurotransmitters are delivered and may elevate levels." So I am thinking (all speculation, though my doctor thinks I'm probably right) that for me, anyway, probably the cod liver oil was too much and was enhancing the efficiency or elevating the levels of glutamate in my brain...which for me isn't helpful, or so it would seem from the strong reaction when I took the cod liver oil. The Mercola krill oil is a smaller dose and I am careful to not take more of it than is recommended. Plus I have carefully removed from my diet all the free glutamates and MSG, so I think that is why I am able to handle the krill... because I am not already overloaded on glutamates.
lisaMarch 11, 2023
Hello, just wondering if others felt depressed after fish oil (Omega 3) as I was. I'd taken it, a smaller dose at first, and started feeling depressed. I never even thought it might be the supplement as it is so good for you in other ways. Then I bought a higher dosage Omega 3, and literally felt sullen and suicidal. It felt like it was holding me back, and I needed to call a suicide hotline. Then .... I started suspecting the fish oil Omega 3. I don't ever want to feel like that again. Just wondering could this be true?
KasheeraMarch 13, 2023
It's such a relief reading these comments, I literally took 1 tsp of cod liver oil and a couple days later I had the worst anxiety I’ve ever experienced in my life. It was mostly me all of a sudden obsessing over my kids health and possible things that could go wrong in the future. I had the worst stomach pains and had the same feeling I used to have when I did public speaking in college. Its been over 10 days and I still feel a bit traumatized by it. I also felt depressed and that nothing in my life was good anymore. The intrusive thoughts would not go away, it literally made me feel suicidal. I was thinking man I can see why ppl with severe anxiety might want to escape these feelings. At first I thought oh maybe its just bad pms but I don’t usually get anxious before my cycle. I suspect I have the mthfr mutation but need to do the genetic test. I also eat eggs everyday and cook with flaxseed oil so maybe too much omega 3's. I only took it once and I still feel the lingering anxiety at times and its been a week or more. Hopefully I feel back to myself by the end of the month.
PEsuper27March 2, 2024
Hello, I just wanted to share some information regarding what I have found about myself and how acetylcholine negatively impacts my mental health. I hope the Reddit link I pasted into the website section links properly and you check it out! Anything that increases acetylcholine in my brain (this includes anything that inhibits the actions of acetylcholinesterase), causes me severe mental strain, depression, dark thoughts and anxiety. I believe this is due to my Homozygous rs6323 slow MAO-A (T/T) gene. Substances include: fish oil, Grape Seed Extract, Green Tea Extract, Huperzine-A, and Thymoquinone (Black Seed Oil).

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