≡ Main Menu

MCT Oil Side Effects & How To Minimize Them

MCT oil has become a very popular supplement due to the fact that it provides the body and brain with an efficient, potent source of fuel for increased energy. Most people that take MCT oil notice slight improvements in physical energy or mental performance. There are a variety of potential MCT oil benefits including: enhancing weight loss efforts, antimicrobial effects (e.g. against Candida), and aiding cognitive function.

It can even be used to help control epilepsy on a ketogenic diet and as a source of fat for individuals who are unable to process other types of fats due to medical conditions. Most sources suggest that MCT oil is a relatively safe dietary supplement when used properly. That said, there are still plenty of individuals who notice that when they take MCT oil – they get side effects, some of which can be very unpleasant.

Side effects from MCT oil are most common when a person first starts supplementing. This is generally due to the fact that the body hasn’t fully adapted to the newly incorporated MCTs. As the body adapts, it is thought that new enzymes are generated to help process the increased medium-chain triglyceride intake.

Factors that influence MCT Oil side effects

If you’re experiencing unpleasant side effects from MCT oils, there are some factors you’ll want to consider to help determine what the potential cause may be. While some side effects are common in the short-term, persistent long-term side effects generally indicate a more pronounced problem that needs to be addressed.

1. Dosage (1 to 3+ tbsp)

Most companies recommend taking anywhere from 1 to 3 tablespoons per day. Some people start out going full throttle with 3 tablespoons and quickly find that they have an array of unpleasant side effects such as diarrhea, upset stomach, intestinal gas, and they feel like crap. Nobody should start out taking the maximum recommended dosage of MCTs unless they want to experience severe side effects.

While the common recommendation may be 1 tablespoon, starting out with just 1 teaspoon can help your body slowly adapt to the MCTs. Just like any drug, you shouldn’t increase to the maximum daily amount immediately. Slowly titrate the dosage upwards over a period of weeks – not days. In other words, take 1 tsp for a week or two, then try 1 tbsp for the following week and determine how you react.

In general, most people experience side effects because they are taking too high of an MCT dosage for their bodies to handle. Those on smaller doses tend to experience a fewer number of side effects with reduced severity compared to individuals who go crazy with high doses.

2. Duration of supplementation

If you’ve only been taking MCTs for a short-term, expect to experience some side effects, especially if you started on a moderate dose. To minimize the side effects over the course of the short-term, it is recommended to start with a very low dose (e.g. 1 tsp) and slowly work your way up to 1 tbsp when you believe you can tolerate it. Most people notice that side effects tend to be most pronounced within the first few weeks of using MCTs on a daily basis.

After several weeks, the body should adapt to the medium-chain triglycerides and be better equipped to process them. Some speculate that certain gut adaptations may ensue following consistent administration of MCTs over the short term such as development of new enzymes. Most people notice that over the long-term, side effects tend to lessen in severity and/or completely subside.

3. Food vs. Empty stomach

Another factor to consider is whether you’re taking MCT oils with or without food. Taking MCTs on an empty stomach may be setting yourself up for unwanted diarrhea, stomach pain, or gastrointestinal issues. Most MCT supplements and medical guidelines suggest that MCTs should be taken with food and should not be heated (e.g. used for cooking) – if they exceed a certain temperature (e.g. 320 degrees), they could be harmful.

Most people find that if the MCTs were causing gastrointestinal distress on an empty stomach, that taking them with food tends to mitigate the unwanted side effects. If you’re taking them with food already, you’re on the right track. You could experiment with taking them right before eating, in the middle of a meal, or immediately after eating to determine which strategy is optimal for side effect reduction.

4. Type of MCT Oil

Most people believe that all MCT oils are created equally and have the same contents. Unfortunately there are several different types of MCTs including: C6, C8, C10, and C12 – indicating the length of the chains. Additionally the purity of various MCTs may not be the same due to how they were processed. (For more information read: “What is MCT Oil?“)

Contents: Using C6 (caproic acid) tends to burn the throat and may create more unwanted side effects than necessary. It is the shortest chain and is also processed most rapidly by the body. Certain products may contain a mixture of all 4 types of MCT oils, possibly increasing the incidence of side effects.

Some sources suggest that C12 (lauric acid) behaves more like a LCT (long-chain triglyceride) and could result in side effects stemming from the longer breakdown. It should also be mentioned that some MCTs are extracted from coconut oils, palm kernel oils, or a combination of both – which may also influence your side effects.

Purity: It has been thought that some MCTs may contain chemicals, solvents, or other unwanted byproducts during their processing. Additionally if they are manufactured and shipped in a plastic container with BPA – this may affect how you react. Make sure you have done your research and found an MCT that is processed well and shipped in a container that doesn’t contaminate the product.

Various companies tend to use distillation to avoid oxidation of various lipids and create a pure product. Others are thought to use various catalysts and solvents to help with the production of their MCT oil. The refining process may be conducted with chemicals that may affect the final product and contribute to side effects that you may not get with a purer MCT. Since dietary supplements are not evaluated by the FDA, it is important to be cautious and make sure you’re getting the highest quality stuff.

5. Individual variation

It is important to keep in mind that while many people experience similar side effects from MCTs, there is significant variation based on the individual. One person may experience side effects over the long-term with MCTs and never feel fully “adapted” to the effects. Another person may take MCTs and not notice much of any side effects. Additionally certain medical conditions, medications, and genetics may influence the effects of the MCTs.

Those that are currently pregnant or breast-feeding may want to avoid using MCTs altogether due to the fact that using MCTs during pregnancy isn’t well studied. Additionally diabetics may not respond well to the build-up of ketones throughout the body. Those with liver problems should consult a medical professional to determine whether MCTs are safe for consumption (especially with formulations incorporating C12 lauric acid).

MCT Oil Side Effects: List of Possibilities

Below is a list of side effects that you may experience while taking MCTs. Keep in mind that the severity and number of side effects will be subject to individual variation based on the factors listed above.

  • Anxiety: Generalized anxiety may occur among individuals with a susceptibility to nervousness or individuals with anxiety disorders. This is likely due to the fact that MCTs can increase mental energy, giving the brain a jumpstart. While this is a relatively uncommon side effect, it is one that has been reported by certain people.
  • Appetite reduction: Many people find that taking MCTs reduces their appetite. This is because MCTs are converted into energy, giving the body and brain a potent boost that they would’ve normally obtained from standard food. Many people feel satiated and less of a need to eat when they supplement MCTs.
  • Flatulence: Some people notice that they tend to get very gassy and fart a lot when they start taking MCTs. This may be a result of taking too high of an MCT dose too quickly. To avoid this effect, try to take the MCTs with food and scale back on food. Most people find that the gassiness subsides after a few weeks of consistent supplementation.
  • Gastrointestinal problems: Some people have pointed out that MCTs cause gastrointestinal irritation. As was mentioned, this could be a result of impurities within the product, but could also be a result of the specific MCTs that are used. It has been speculated that the shorter the chain of the MCT (e.g. C6), the more gastric distress a person is likely to experience due to the speed of processing.
  • Diarrhea: Experiencing a severe bout of diarrhea is extremely common when people first start taking MCTs. In fact, diarrhea is perhaps the most common side effect of all. If you are experiencing diarrhea as a side effect, lowering the amount of MCTs that you’re taking is a smart idea. Also consider taking your MCTs with food as it may help reduce gastrointestinal distress.
  • Digestive problems: If you suspect that the MCT oils are affecting your digestion, you’re probably right. Many people notice that their stomach feels gassy, they experience diarrhea, or abnormal bowel movements when they first start supplementing MCTs. Assuming you have no medical conditions that would be causing digestive issues, reduce the MCT dosage until your digestion stabilizes.
  • Dizziness: A common reaction to nearly any drug or supplement is that of dizziness. If you’ve become dizzy as a result of MCT oil, you may want to reduce the dosage, try a different brand, or consume it with food. This isn’t a very common reaction, but may be related to increased mental energy and/or anxiety from the MCTs.
  • EFA deficiency: There is some speculation that supplementation of medium-chain triglycerides (MCTs) may result in essential fatty acid deficiency. While some studies found no such problem, a couple studies involving administration of MCTs to infants found that EFA levels were deficient as a result. Make sure you are getting sufficient EFAs to avoid becoming deficient; which could lead to its own subset of side effects.
  • Headaches: Certain people are prone to headaches when taking MCTs, especially when they first begin supplementing. While the cause of these headaches is unknown, they may be related to the way the MCTs were processed, impurities, composition of the oil, or even a result of increased mental energy. High levels of mental energy from MCTs may lead some people to experience headaches.
  • Hot flashes: In some cases, individuals may notice an increase in body temperature from the MCT oil. This increase in temperature may occur in the form of “hot flashes” in which it feels as if the body is suddenly heating up. This may be due to the speed by which the MCT oil is being absorbed and metabolized – thus giving the body more energy. Hot flashes as a result of taking MCT oil are thought to be more common among women.
  • Hunger: Most people experience a reduction in appetite after taking MCT oil due to the fact that it is an efficient source of energy. However, some people have reported feeling increasingly hungry following MCT consumption. This may be due to a variety of other factors including drugs or supplements that the person is taking as well as dietary factors. However, one study shows that MCTs may bind to ghrelin and convert it into an active form that may stimulate appetite. Keep in mind that most evidence contradicts this side effect, but it is one that people have reported.
  • Irritability: A lesser reported side effect from MCT oil is that of irritability. If you notice that you’re becoming irritable, it may be due to the fact that you’re brain is overstimulated from the energy the oils have provided. To decrease the irritability, scale back or tweak the dosage so that you’re taking an amount that makes you feel less irritable.
  • Nausea: If you feel nauseous while taking MCTs, you’re not alone. Many people report nausea in the early stages of supplementation as well as if they take too high of a dose. While nausea is a commonly reported side effect, it shouldn’t persist over a long term. If nausea doesn’t subside after a few days or weeks, you may want to consider that the brand of MCTs may be problematic and/or your dosing may be too high.
  • Perceptual changes: The fact that MCTs provide the brain with increased energy and elevate levels of circulating ketone bodies may result in perceptual changes. Dietary intake is known to affect brain function, and therefore a ketogenic diet, perhaps induced by increased consumption of MCTs may result in a noticeable perceptual shift.
  • Stomach aches: As was mentioned, MCT oil can lead to gastrointestinal distress, diarrhea, flatulence, and other digestive issues. Stomach aches are very common when a person first starts taking MCTs. Most people will adapt to the MCT oil and the stomach aches should subside after several weeks. If you’re experiencing stomach problems, scale back the dose and make sure you’re taking the MCT oil with food.
  • Throat irritation: If you take certain types of MCTs on an empty stomach, you may feel as if they are slightly burning the lining of your throat or stomach. It has been suggested that shorter chained MCTs (e.g. C6 caproic acid) may be to blame. Make sure your formulation is void of C6 as this may be the culprit for the burning sensations.
  • Tiredness: A counterintuitive reaction to MCTs is that of sleepiness or feeling increasingly tired. Most people find that MCTs are very physiologically activating, but a select number of people notice that they feel even more tired after taking the supplement. Be sure to rule out other causes of the sleepiness and discontinue the MCTs to verify that this was a reaction to them.
  • Vomiting: While a majority of people do not end up vomiting from MCTs, some cannot bear the nausea and end up looking for the puke bucket. If you experience vomiting as a side effect, you are likely taking way too much MCT oil and aren’t taking it with food. If you are vomiting from a very small amount, you may have an impure product or maybe aren’t able to tolerate the product; in this case discontinuation should be advised.
  • Weight changes: Some people experience weight changes when supplementing MCTs. Many athletes and bodybuilders use MCTs as an efficient means of providing the body with energy and decreasing appetite. A majority of people experiencing weight changes following MCT supplementation report a minor degree of weight loss as opposed to weight gain.

How to minimize MCT oil’s side effects…

If you are experiencing unwanted side effects from MCTs, first verify that nothing you’re taking is interacting with it and that you don’t have a medical condition that’s contributing to the problem. Also check the source of the MCTs, the composition, and ensure that the MCT oil hasn’t already expired (rancid oil will set you up for side effects).

  1. Take it with food: Most bottles of MCT suggest taking it with food to reduce side effects. If you are currently taking it on an empty stomach, try taking it after you’ve had some food and determine whether side effects are less pronounced. Many people find that taking MCTs with food mitigates most of the unwanted effects.
  2. Reduce the dosage: An obvious strategy to reduce the side effects of MCTs is to reduce the dosage. If you’re currently taking 1 tbsp and noticing significant side effects, scale back to 1 tsp and reassess your experience. Taking too high of dosage, especially in early stages of supplementation can result in side effects. If 1 tsp is causing problems, take only a 1/2 tsp and titrate upwards as your body adapts.
  3. Switch types and/or brands: If you’re taking a certain type of MCT oil (e.g. C12 lauric acid), you may want to switch to a formulation with C10 or C8. In addition to the specific MCTs that are utilized, you may want to switch to a different brand to determine whether the processing, production, or manufacturing may be an issue. Some manufacturers use methods to produce MCTs that may result in impurities or poorer quality products.
  4. Wait for body to adapt: In some cases it’s just a matter of playing the waiting game. Since most people aren’t used to taking MCTs, when you start supplementing, the MCTs are a new stimulus that your body needs to process. In the early stages of supplementation, your body isn’t prepared for the MCTs, but over time, it comes to expect them and knows how to process the medium-chain triglycerides without side effects.
  5. Discontinue: If the effects from MCT oil are severe, discontinuation is probably the best strategy. It’s not worth supplementing medium-chain triglycerides if they are causing significantly more distress than benefit.  No one wants to be stuck on the toilet for hours because they took 1 tsp of MCTs… If you sense that you aren’t able to adapt to the MCTs, it’s best to listen to your body.

Who should NOT take MCT Oil?

While MCT oil is thought to be safe for most people, there are certain people that should consider avoiding medium-chain triglyceride supplementation.

  • Breastfeeding or Pregnant: There isn’t sufficient research to support the safety of MCT oil among breastfeeding or pregnant women. There is even some evidence that medium-chain triglycerides may result in depletion of EFAs (essential fatty acids) in the unborn baby. To be on the safe side, avoid this supplement if you’re pregnant.
  • Diabetes: Among those with diabetes (primarily those with Type 1), MCTs may result in high build-up of ketones throughout the body. This is a result of cells burning fat instead of glucose for energy. This can result in a condition called “ketoacidosis” which can poison the body in diabetics, resulting in diabetic coma (passing out), and may be fatal.
  • Liver problems: While shorter chain MCTs are thought to bypass the liver, longer chain MCTs (e.g. C12 lauric acid) may result in liver problems. Regardless of the MCT composition that you’re considering, always consult with a medical professional if you have any preexisting liver disease or liver problems (e.g. cirrhosis).

MCT Oil: Weighing Benefits vs. Side Effects

If you’re taking MCT oil and experiencing side effects, keep in mind that they may eventually subside as your body gets used to the oil (over a period of weeks). If you are still experiencing side effects after moderate or long-term usage, you should take the time to weigh the benefits you’re getting from the MCT with the side effects.

If the side effects are so severe that you cannot function, obviously discontinuing the MCT oil is a smart idea. However, if you’re getting considerable benefit from the MCT oil (e.g. cognitive function), minor side effects may be justified. Always conduct a benefits vs. side effects analysis after several weeks of MCT supplementation.

Have you experienced side effects from MCT Oil?

If you’ve been using MCT oil, feel free to share whether you noticed any unwanted side effects in the comments section below. Feel free to mention the particular brand of MCT oil, how long you’ve been taking it (short, moderate, or long-term) as well as the specific subtype of the oil (e.g. C6, C8, C10, C12) and its source. Also discuss whether you have any medical conditions or are taking any medications that may be contributing to the side effects that you’re experiencing.

Realize that most people notice side effects in the short-term, but they tend to subside after a few weeks. Before blaming the MCT oil for side effects, also consider any other medications and supplements that you may be taking. I’ve been taking MCTs for several months and haven’t noticed any major problems other than intermittent stomach aches when taken on an empty stomach at a high dosage.

  • Source: http://www.ncbi.nlm.nih.gov/pubmed/15677766

Related Posts:

{ 92 comments… add one }
  • maria July 14, 2018, 3:35 am

    “Liver problems: While shorter chain MCTs are thought to bypass the liver, longer chain MCTs (e.g. C12 lauric acid) may result in liver problems. ”

    How do you determine how long the chain of MCT oil you are taking? I bought mine from Sprouts and enjoyed a surge of energy for 6 weeks while combining it with the Plant Paradox diet. I decided to run a blood test to establish a baseline, feeling certain that it would reflect great numbers.

    Instead, the doctor called me right away, saying I needed further testing (a $400 dollar test) on my liver! I stopped taking the oil… I was also taking Ghee with my coffee, and lots of other good fats (avocado, olive oil) in larger amounts than the usual.

    I haven’t gone back to re run my tests. I am back to feeling tired and drained. :( I would like to know the difference between long and short chain MCTs. I must have been taking the long chain.

  • Larry July 6, 2018, 12:05 am

    MCT, no problem. I’m 66 years old and experienced a little slight burning on upper stomach after starting first time with 2 TBL spoons. Not any problems after that. Just wanted to say to those interested that not everyone has these dramatic effects.

  • George June 28, 2018, 4:32 am

    Second day of 1 TSP dose. My first was in a smoothie, second was in my Life brand cereal. Sure it’s not a ketogenic diet, but I’m simply trying to add the MCT’s in my diet before going full bore. Got a pretty bad migraine, took me out for most of the day.

    I’ve had a very bad concussion, that left me with partial amnesia, as well as a debilitated state in which I misplace words, or forget words. As example, I had at one point forgotten the word for water.

    And instead of not being able to find the such words that I misplace, with difficulty the last two days I’m able to find them. MCT oil has already changed my life, two days in.

  • SRR1 June 18, 2018, 5:29 pm

    I almost ended up in the hospital again this morning but thankfully realized it was the Bulletproof Brain Octane Oil causing the symptoms. I have been taking it for about 3 months and combine it with collagen peptides in my morning coffee. I was out of collagen this morning and took about 2tbs of oil in my coffee.

    About an hour later I began experiencing severe symptoms that included diarrhea, vomiting, dizziness, perceptual changes like feeling separated from my body, increased heart rate, a burning feeling in my stomach and shaking. These same symptoms occurred about a month before when I was picking my children up from school. I had to pull over and call my husband for help.

    He took me to the ER. They did blood work but could find nothing. We chalked it up to a stomach bug and I felt better the next day. I have been experiencing bloating, depression (for the first time in my life) and sleep disturbances lately and after reading the other comments I feel sure that it is the oil that is causing this. Obviously, this is not a product I will continue using.

  • Ruth May 10, 2018, 3:11 pm

    First time I tried MCT oil was with a coffee and got a upset stomach and vomiting five hours later. I thought it was the combination of coffee and the MCT oil. I didn’t realize it was the oil that got me sick.

    Today I tried it again, 1 tablespoon MCT oil currently dealing with bad nausea loose stools. I’m waiting be vomit. I’m not giving up. I will bring the dose down to 1/4 teaspoon. Boy, the directions should not say start with 1 to 3 tablespoons.

    It’s very misleading and makes you want to throw in the towel and give up. I’m using the natural force brand of MCT oil. It’s been four hours and then side effects are still with me. 😬

  • nancylou thomas April 19, 2018, 9:53 am

    I discontinued after the initial shock of pain, cramping, dizziness, weakness, flushing and rash… but found MTC powder in a flavored drink… No problems whatsoever. Now to get rid of that large bottle of oil!!!

  • Laur April 18, 2018, 1:35 pm

    Have been taking the MCT oil in my coffee for 5 weeks now. It’s been happening more and more – I get very severe burning on my right side (I’m assuming my liver) with hot flashes and dizziness. Probably going to have to cease ingestion for a bit. Too much!

  • Nancy March 27, 2018, 11:43 pm

    Started today with NOW MTC. Made my protein drink and took 1 level tsp… finished protein drink… yikes. Minutes later: severe cramps, belly ache, hot flashes, nausea off to the powder room… sat down… whew… it passed (did notice a pink rash on part of arms but that too passed and no diarrhea.

    Several hours passed: no more/other side effects. Okay, tomorrow will try just 1/4 to 1/2 tsp. maybe after a small bowl of hot oatmeal… and see if that helps. Thanks.

  • Debbie March 26, 2018, 12:55 am

    I’ve been taking NOW brand MCT oil for roughly 4-5 weeks. Started at 1 Tbsp. Horrific cramps and quality time on the toilet. Lowered dose to 1 tsp after a week. No side effects. Sweet! Continued with 1 tsp for a week before going to 2 tsps.

    It was a hit and miss on the side effects. Some days good. Some days an intestinal hell. Now I am steady on the side effects. Bloating, gas, going between loose and frequent to not going at all, horrific indigestion, hot flashes, anxiety, depression, insomnia and irritability… just to name a few.

    I eat clean, exercise, and am 47 without a gall bladder. I’m sad MCT oil hates me so because the brain power and fog removal were amazing. But definitely not worth all this!

  • Lulu March 10, 2018, 10:37 pm

    I discovered today a trick that helped. I took more MCT oil than usual to get back into ketosis after a little slip up. I took about 1.5 TBSP (of course on an empty stomach – doh!) and a few minutes later started to get that familiar severe stomach ache.

    I immediately drank some water, hoping to dilute the oil in my stomach but that did not help. When I felt the next wave coming on I drank some HOT water and the wave passed quickly and after that I felt great, no more stomach ache, no nausea, no gassiness, no diarrhea, no nothing.

    I don’t know if it will work again or if it’s a one and done but it’s worth trying.

    • Jenn April 19, 2018, 2:20 pm

      Thanks for the tip. I’ll keep some hot water handy, maybe it’ll help? I just tried MCT oil for the first time (mixed 1 tbsp with diluted coconut milk, vanilla, a little agave syrup, and 1 tbsp of coconut oil.)

      Felt normal for 6 hours and then got terribly sick… =/ I don’t want to give up entirely though! I’m going to try scaling it back to 1 tsp and cross my fingers.

Leave a Comment