Humira (Adalimumab) is a biologic, immunosuppressant medication sold and marketed by the pharmaceutical company AbbVie Inc. More specifically, Humira functions as a TNF inhibitor whereby it binds to and blocks the physiologic effect of the proinflammatory cytokine known as “TNF-alpha.” Blockade of inflammation induced by TNF-alpha makes Humira useful for the treatment of many autoimmune conditions, including: rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn’s disease, ulcerative colitis, chronic psoriasis, hidradenitis suppurativa, and juvenile idiopathic arthritis.
Through is suppression of TNF-alpha, many Humira users find that the medication effectively manages symptoms of their autoimmune conditions. That said, because Humira substantially modulates immune function and other aspects of physiology, many individuals experience side effects. A side effect that many prospective Humira users are concerned with and/or may experience is weight gain.
Humira (Adalimumab) & Weight Gain (Potential Causes)
In the event that you experience weight gain as a side effect of Humira, listed below are some possible causes. Realize that the specific cause(s) of weight gain among Humira users is subject to individual variation. Certain Humira users may gain weight as a result of reversing their autoimmune condition (that was causing their body to stay underweight), whereas others may gain weight as a result of changes in metabolic rate. If you have questions about why you’re gaining weight on Humira, talk to a medical doctor – preferably a rheumatologist.
- Appetite increase: Some Humira users have reported increased appetite as a side effect of treatment. If your appetite increases, this may lead you to consume more food (i.e. calories) than usual which would explain your weight gain. In some cases, an appetite increase along with greater food consumption is actually a good thing – especially among those who had abnormally low appetites and/or were underweight as a result of an untreated autoimmune condition. For some, an appetite increase may be a sign that an underlying autoimmune condition is being adequately treated.
- Bloating: A subset of Humira users might experience bloating and/or increased water retention as a side effect. This increased water retention may be noticeable in the stomach, midsection, and/or throughout the body. If you’re bloated and step on the scale, your body weight may be noticeably heavier than usual. That said, while bloating may be uncomfortable, the weight gain that you’re experiencing may be mostly water weight (not fat accumulation).
- Constipation: A side effect of Humira treatment that some individuals experience is constipation, or the inability to efficiently pass bowel movements. If you experience increased constipation while taking Humira, this may explain some of your weight gain. If digested food hasn’t been excreted (because you’re constipated), you’re going to weigh more than usual when you step on the scale.
- Cravings: In addition to experiencing an overall increase in appetite, some individuals report strong food cravings while using Humira, particularly for carbohydrates and/or unhealthy (hyperpalatable, calorically-dense) foods such as: candies, cookies, pastries, etc. It is unclear as to why food cravings might occur among Humira users. In the event that you experience food cravings that you cannot resist while taking Humira, there’s a good chance that you won’t be able to resist – which might result in weight gain.
- Depression: Although excessive inflammation and untreated autoimmune disorders can cause depression, some individuals experience depression as a side effect of TNF inhibitors like Humira. If depression occurs, this could cause some individuals to increase food consumption as a coping mechanism. That said, depression is also associated with decreased motivation, lower energy levels, and poorer self-control – each of which could indirectly lead to weight gain via reduced physical activity, slowed metabolism, and/or making unhealthy food choices.
- Fat storage: It is understood that TNF (tumor necrosis factor) can influence aspects of lipolysis and fat storage. What’s more, research suggests that high concentrations of TNF-alpha can induce fat loss (and weight loss) among persons with autoimmune conditions. Because Humira blocks the action of TNF-alpha, individuals who’ve lost fat from high TNF-alpha concentrations may regain or store more body fat than usual. Any increase in fat storage throughout the body will account for some weight gain on Humira.
- Fatigue: Untreated autoimmune disorders can cause significant fatigue and lethargy whereby it becomes difficult to get out of bed each morning. Treating an autoimmune condition usually helps increase one’s energy level. That said, a side effect reported by some Humira (adalimumab) users is extreme fatigue. If you are exceptionally fatigued while using adalimumab, this may cause you to reduce your physical activity throughout the day such that you burn fewer calories than usual – and end up gaining weight.
- Gut bacteria: Most evidence suggests that autoimmune disorders are associated with unfavorable changes in gut bacteria (i.e. dysbiosis) and that treatment with adalimumab usually improves gut bacteria composition. That said, it is unclear as to whether all changes in gut bacteria during adalimumab treatment are favorable. It’s possible that Humira might increase concentrations of certain gut bacteria that stimulate appetite, cause bloating, and/or increase fat storage – all of which are associated with weight gain.
- Hormone changes: A majority of data indicate that autoimmune disorders are associated with hormonal abnormalities, and that treatment with TNF-inhibitors like Humira generally normalizes hormone concentrations. Nevertheless, it’s possible that Humira might affect concentrations of circulating hormones in a way that promotes weight gain and/or fat storage. If you notice significant changes in the concentrations of certain hormones while using Humira, there’s a chance that these might explain some of your weight gain.
- Lower motivation: Because many patients experience mental fatigue as a side effect of Humira, this could result in lower motivation to stay active or exercise. If you experience a motivational deficit while taking Humira, and the deficit leads you to exercise less than you normally would – this may result in decreased energy expenditure, slowing of your metabolism, and predictably, weight gain.
- Muscle gain: Many autoimmune conditions like rheumatoid arthritis are associated with weight loss as a result of muscle wasting. Muscle wasting refers to decreased strength and mass in the muscles. When a person starts using a medication like Humira, it may help reverse the autoimmune-induced muscle wasting (cachexia) and rebuild some muscle mass. Assuming a significant amount of muscle is added during treatment, this could account for some weight gain.
- Slowed metabolism: It is thought that Humira treatment might slow resting metabolic rate (RMR) such that your body burns fewer calories at rest than it did before treatment. There are many potential ways that Humira could slow resting metabolic rate including: reducing TNF alpha; altering concentrations of various hormones; and inducing fatigue (which makes it difficult for you to exercise and keep your metabolism high). If your metabolism slows while under the influence of Humira, this effect may be responsible for your weight gain.
Humira (Adalimumab) & Weight Gain (Research)
Included below are journal articles in which the effect of Humira or TNF-inhibitors on body weight was documented. Based on the available data, it seems as though weight gain is a common side effect associated with the use of TNF-inhibitors, including Humira.
2013: Weight gain and tumour necrosis factor-alpha inhibitors in patients with psoriasis.
Tan, Baker, and Foley conducted a trial comparing the effects of TNF-inhibitors to non-TNF modulators – on bodyweight and body mass index (BMI) of 143 patients with psoriasis. Researchers conducted a retrospective analysis whereby they assessed bodyweights and BMIs of patients before initiation of treatments, as well as at week 12, week 24, and week 48 of treatment. A total of 286 treatment courses were administered in total to the 143 patients, including: 178 treatments with TNF-inhibitors (54 adalimumab; 61 etanercept, 63 infliximab) and 108 treatments with non-TNF modulators (73 on efalizumab and 35 on ustekinumab).
Findings indicated that use of TNF inhibitors (adalimumab and infliximab) yielded significant weight gain from week 12 until week 48. At week 12, the 54 adalimumab (Humira) recipients gained an average of 1.5 kg (3.3 lbs.), and by week 24, had gained an average of 2.2 kg (4.8 lbs.). At the week 48 (trial endpoint), the adalimumab recipients had gained 2.4 kg (5.29 lbs.).
Researchers concluded that treatment with adalimumab (Humira) is associated with a significant increase in bodyweight and BMI (body mass index). This research clearly supports the idea that adalimumab (Humira) induces weight gain. Moreover, it’s unknown as to how much additional weight gain might’ve been observed in an even longer-term study (exceeding 48 weeks).
- Source: https://www.ncbi.nlm.nih.gov/pubmed/24164178
2012: Weight Gain and Hair Loss during Anti-TNF Therapy.
Lutf and Hammoudeh conducted a study to determine the effect of anti-TNF medications on rates of weight gain and hair loss among patients with rheumatic diseases. For this study, researchers gathered data from 150 patients diagnosed with rheumatic diseases (82 rheumatoid arthritis; 34 ankylosing spondylitis; 32 psoriatic arthritis; 4 non-specified conditions). To gather data about anti-TNF medication side effects, researchers interviewed patients with questionnaires at rheumatology clinics.
Patients who complained of weight gain and/or hair loss were asked additional questions to elucidate the relationship between these adverse effects and anti-TNF medication use. For example, patients were asked if they ever stopped using their medication as a result of adverse effects and if the adverse effects reversed (e.g. weight was lost) after medication discontinuation. Furthermore, medical files of each patient were reviewed to determine weight changes before, during, and after cessation of anti-TNF medications.
Results indicated that clinically significant weight gain occurred in 20 (13.3%) of the 150 patients being treated with anti-TNF medications. The average weight gain among these patients was 5.5 kg (12.12 lbs.). In 5 patients, the weight gain was deemed problematic enough to warrant discontinuation of anti-TNF medication. Researchers concluded that weight gain appears to be associated with anti-TNF therapy and may be a reason as to why a subset of patients discontinue anti-TNF medications.
- Source: https://www.ncbi.nlm.nih.gov/pubmed/22927859
Based on the research, how much weight will you gain from Humira (Adalimumab)?
A significant amount. Firstly, understand that not all Humira users will gain a significant amount of weight during treatment. Research suggests that around 13.3% of individuals who use TNF-inhibitor medications will experience significant weight gain. If you are a person who is prone to Humira-induced weight gain, the amount of weight that you gain will likely be clinically significant (defined as a weight increase by at least 7% from pre-treatment).
Both short-term and long-term data (in which the effect of Humira on body weight was assessed) indicate that Humira users may gain the following amounts:
- Within 12 weeks: ~3.3 lbs. (possibly up to 13.22 lbs.)
- Within 24 weeks: ~4.8 lbs. (possibly up to 14.55 lbs.)
- Within 48 weeks: ~5.29 lbs. (possibly up to 19.4 lbs.)
A study in which patients receiving TNF-inhibitors (not just Humira) reported average weight gains (among patients who experienced weight gain as a side effect) of 5.5 kg (12.12 lbs.) in just 12 weeks. The evidence is abundantly clear that some Humira users will gain a significant amount of weight over the short-term and long-term. It is unknown as to whether weight gain might persist after 1-year of treatment, and if it does, to what extent. Moreover, it remains unknown as to how long it may take for body weight to plateau (after the gain) and remain stable after Humira initiation.
Variables that influence Humira (Adalimumab) weight gain
There are multiple variables that might influence the amount of weight gain that you experience while using Humira. These variables include: your pre-treatment weight; prior medication use; duration of Humira treatment; genetics; lifestyle; Humira dosage; and concurrent substance use. In most cases, it is the combination of these variables that determines which Humira users will end up gaining weight, as well as the significance of the weight gain.
- Autoimmune-related weight loss: It is known that for many individuals, untreated autoimmune disorders can lead to significant weight loss via appetite suppression, muscle wasting, and fat loss. Some suspect that autoimmune-induced weight loss is caused chiefly by elevated concentrations of TNF-alpha. In any regard, if you exhibited autoimmune-induced weight loss prior to taking Humira, you may be more likely to regain weight during Humira treatment than persons who never experienced weight loss attributable to their autoimmune condition. Essentially, gaining some weight with Humira may be your body’s way of reverting itself back to a healthier homeostasis – especially if you were underweight.
- Prior medication use: If you used other medications before transitioning to Humira, there’s a chance that those medications might’ve induced weight gain or weight loss. If you used a medication (before Humira) that caused weight loss (e.g. methotrexate), you may end up gaining weight back once you switch to Humira. In this case, any weight gain that occurs after transitioning to Humira may be more due to homeostatic rebound effects (opposite of what was experienced on the previous medication) than a side effect of Humira. On the other hand, if you were already using a medication (before Humira) that caused weight gain, you may not experience any weight gain while using Humira (because your body weight has already plateaued).
- Duration of Humira use: Certain individuals may experience significant weight gain after a short-term of Humira treatment (e.g. 12 weeks) followed by a plateau, whereas others might only experience significant weight gain after a moderate-term (e.g. 24 weeks) or long-term (e.g. 48 weeks) of treatment. Others might experience ongoing weight gain that starts in the short-term and continues over a long-term. Nonetheless, you should consider that the total duration over which you’ve used Humira might determine the amount of weight you gain. Research suggests that long-term Humira use is associated with greater weight gain than short-term use.
- Humira dosage: It’s possible that the dosage of Humira administered influences likelihood of weight gain and/or significance of weight gain among users. Among persons who are prone to weight gain on Humira, it’s likely that larger doses will induce greater weight gain than smaller ones. This is because larger doses exert more substantial immunomodulatory effects (via TNF-alpha inhibition) and physiologic effects than smaller doses. For this reason, you should not be surprised if you gain more weight on a high Humira dose than a lower one.
- Genetics: Individuals who gain weight while taking Humira may have genetics that differ from the majority of the population. It is known that a majority of Humira users will not experience clinically significant weight gain (defined as 7% body weight increase), even over a long-term. For this reason, it is suspected that individuals who gain weight on Humira may express certain genes (or epigenetic expressions) that increase susceptibility to Humira-induced weight gain. Another possibility is that individuals who gain weight lack certain genes that protect against Humira-induced weight gain. Although the exact role of gene expression in regards to Humira-induced weight gain is unknown, drug-gene-weight interactions are a possibility.
- Concurrent substances: If you’re using other substances (medications and/or supplements) with Humira, it’s possible that concurrent substance use might explain your weight change (or lack thereof) on Humira. You should first evaluate whether the concurrent substance(s) that you’re taking are associated with weight change. For example, if you’re using another medication that’s known to cause weight gain, perhaps most of your weight gain is actually related to the other medication. Another possibility could be that the mechanisms of Humira-induced weight gain are synergistic with those of another medication you’re using – ultimately amplifying the amount of weight that you gain during treatment. On the other hand, using medications that cause weight loss (e.g. methotrexate) with Humira – might prevent Humira-induced weight gain. In short, realize that your weight change on Humira may not be entirely attributable to Humira if you’re taking other medications.
- Lifestyle: While Humira can cause weight gain, not everyone who gains weight while taking Humira should necessarily blame the drug. If you live a sedentary lifestyle, are highly stressed, eat unhealthy foods, eat excessive calories, and/or don’t get proper sleep – these lifestyle factors could directly contribute to your weight gain, regardless of Humira. On the other hand, if you stay physically active, eat a balanced diet, restrict your calories, practice stress reduction, and get quality sleep – you may be less prone to Humira-induced weight gain.
How to minimize weight gain on Humira (Adalimumab)
It is known that significant weight gain can occur as a side effect of Humira. If you want to minimize your chances of gaining weight on Humira (or prevent further weight gain), you may want to consider implementing some of the strategies listed below. Understand that you should never implement any of these strategies without first consulting a medical professional (e.g. rheumatologist) to ensure that they’re safe in accordance with your current medical status.
- Control your calories: While some weight gain may be inevitable while using Humira, you may want to minimize the amount of weight that you gain. One strategy for minimizing weight gain involves tracking and controlling your calories. If your body burns an average of 2000 calories per day, you should eat around 2000 calories to maintain your current weight – or slightly less than this amount to gradually lose weight.
- Stay physically active: Because not everyone bothers tracking calories while taking Humira, another option could be to stay physically active. You don’t need to do intense workouts, but try to get some light physical exercise each day (e.g. go for a 30-minute walk). Staying physically active will help keep your metabolism high and enable you to burn more calories than staying sedentary.
- Manage Humira side effects: Sometimes Humira side effects may be culpable for your weight gain. For example, if you’re experiencing bloating and/or constipation, this could account for a heavier body weight when you step on the scale. Asking your doctor about medications and/or supplements that might help you manage side effects (e.g. fatigue, constipation, etc.) that are leading to weight gain might help you get your weight under control.
- Dosage adjustments: Usually your rheumatologist will have calibrated your Humira dosage to effectively treat your autoimmune condition. However, if you’re gaining a lot of weight during treatment, you may want to ask your doctor whether you could try a lower Humira dose – or attempt to find the “minimal effective dose” (lowest dose needed to control your symptoms). If a lower Humira dose (than what you’re currently using) manages to control autoimmune symptoms, you may lose some weight when you decrease the dosage.
- Concurrent medications: If you’re taking other substances with Humira and are gaining weight, you may want to stop using all medically-unnecessary substances. In some cases, cutting out medically-unnecessary medications and/or supplements from your regimen may stop or reverse the weight gain that you experienced. On the other hand, if you aren’t taking other substances with Humira, you may want to ask your doctor about prescribing adjunct medications and/or supplements to increase your energy level, metabolism, motivation, and/or self-control to prevent weight gain.
Note: If you’ve gained an unhealthy amount of weight while using Humira and/or experienced severe Humira side effects, you may want to talk to your rheumatologist about transitioning to another medication (one that isn’t associated with weight gain). Moreover, realize that if Humira is effectively treating your autoimmune condition, you may need to accept some weight gain as a tradeoff.
Have you experienced weight gain on Humira (Adalimumab)?
If you’ve used Humira and experienced weight gain, weight loss, or no weight change – share this in the comments section below. If you gained or lost weight, mention the approximate amount that you gained or lost. Provide some details about your weight change on Humira such as: whether you were underweight before treatment; how your body composition has changed since starting Humira (e.g. increased muscle, increased fat, etc.); and how quickly you experienced the weight change after starting treatment.
Also note things like: how long you’ve been using Humira; your Humira dosage; and whether you’re taking other medications (or supplements) along with Humira. If you’re taking other medications with Humira, have you considered that those substances might’ve also affected your weight? If you’re a long-term Humira user, mention whether the weight gain has continued or eventually reached a plateau.
Are there any specific reasons that you believe you ended up gaining weight on Humira? Examples of possible reasons might include: increased appetite; slower metabolism; lower energy and decreased motivation for exercise. Have you tried controlling your calories and physical activity throughout treatment to keep your weight stable? If you’ve figured out any ways to keep your weight stable while using Humira, share these strategies in the comments section.