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What is 5-HTP and Why Was It Banned?

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5-HTP or 5-hydroxytryptophan is a dietary supplement that is used by many people to help with conditions such as depression, anxiety, sleep disorders, and primary fibromyalgia syndrome. Some people use it to treat migraines or other types of chronic primary headache. 5-HTP is sold under the brand name Oxitriptan as an over-the-counter product. Although there is limited evidence supporting 5-HTP’s place in therapy for the listed conditions, 5-HTP plays a role in a wide variety of health conditions caused by low serotonin levels. More research is needed to have a better understanding of the role of this chemical. Please continue reading to learn more about this popular supplement.

What is 5-HTP?

The body makes 5-hydroxytryptophan (5-HTP) from an essential amino acid called L-tryptophan, which is naturally found in red meat, poultry, eggs, and dairy. 

After tryptophan is converted to 5-HTP, it can be further converted into the neurotransmitter serotonin. Therefore, the amino acid tryptophan and 5-HTP are called serotonin precursors since they are used to make the final product, serotonin. Serotonin relays signals between nerve cells in the central nervous system and regulates mood, appetite, and behavior, among other important aspects affecting our overall health. As you may know, low serotonin levels can lead to depression, sleep problems, anxiety, and unwanted weight gain. The beneficial effects of 5-HTP are due to its ability to increase serotonin levels in the body. 

As mentioned above, tryptophan is found in foods. However, eating foods that contain neurotransmitter precursors like the amino acid L-tryptophan does not raise serotonin levels in the body very much. For this reason, 5-HTP dietary supplements are available to support serotonin synthesis. These supplements are commercially produced from an African plant called Griffonia simplicifolia

What is 5-HTP used for?

One thing to keep in mind is that 5-HTP is a herbal supplement, and the U.S. Food and Drug Administration (FDA) does not regulate supplements the same way they do with prescription medications. Therefore, for 5-HTP or any other supplements, there is not enough data to prove or invalidate the supplement’s side effects and effectiveness. 

5-HTP can boost serotonin levels and have a positive effect on mood, depression, anxiety, sleep, appetite, and pain. However, there is no strong scientific evidence that 5-HTP can quantify the increase in serotonin production or the body’s serotonin levels. Nonetheless, here are some of the potential benefits of taking this serotonin precursor. 


Depression is a mental health condition that occurs due to an imbalance in serotonin levels in the body. Taking a clinically effective serotonin precursor like 5-HTP can help to manage depression symptoms in some people. This supplement has even been found to work as effectively as prescription antidepressant drugs in some depressed patients. Moreover, some people with treatment-resistant depression have benefited from taking 5-HTP to restore serotonin levels. Research suggests 5-HTP has stronger antidepressant effects when combined with other supplements or antidepressant medications. However, there is not enough scientific evidence to support the use of 5-HTP to treat depression at the current time. 

Weight Loss

5-HTP may help in promoting weight loss by counteracting hunger-producing hormones and increasing satiety (feelings of fullness). Studies have found that people who take 5-HTP every day consume fewer calories compared to those not taking this supplement. Moreover, obese adult subjects treated with 5-HTP have been shown to have reduced carbohydrate intake, which can help with blood sugar control. In addition, the antidepressant efficacy of 5-HTP is believed to reduce excessive calorie intake due to stress eating caused by depression. 


This is a condition characterized by generalized muscle pain, weakness, fatigue, anxiety, and sleep problems. The cause of fibromyalgia remains unclear, but low serotonin levels are believed to play a role. This has led scientists to suggest that supplementing with 5-HTP may improve symptoms in people with fibromyalgia. However, there has yet to be enough research to draw any firm conclusions.

Migraine headaches

Research suggests that migraine and chronic tension-type headache may be associated with low serotonin levels. 5-HTP can, therefore, potentially help treat migraines. Studies have shown that taking 5-HTP can help with the intensity and duration of migraine headaches.

Is there a downside to taking 5-HTP dietary supplements?

Side Effects

Common side effects of 5-HTP include gastrointestinal symptoms like stomach pain, heartburn, nausea, vomiting, and diarrhea. Less commonly, this supplement can cause adverse effects like headache, insomnia, muscle problems, sexual difficulties, and a rapid or irregular heartbeat. Taking very large doses of 5-HTP (more than 6 grams a day) can cause severe muscle spasms and stomach issues. 

Eosinophilia-Myalgia Syndrome

5-HTP has been linked to certain potentially fatal adverse reactions, specifically eosinophilia-myalgia syndrome (EMS). There is not enough evidence to prove whether EMS is caused by 5-HTP itself, some contaminant in 5-HTP products, or other factors. Doctors advise taking 5-HTP with caution until we know more about this serious complication. 

Drug Interactions 

It is also important to check for drug interactions between 5-HTP and your other non-prescription and prescription drugs. Taking this supplement with other serotonergic drugs like selective serotonin reuptake inhibitors (SSRIs) or monoamine oxidase inhibitors (MAOIs) can lead to too much serotonin and a serious condition called serotonin syndrome. Other drugs and supplements that can interact with 5-HTP include carbidopa, St. John’s Wort, and SAM-e. Also, 5-HTP can interfere with the results of a 5-HIAA urine test that is used to diagnose or monitor certain types of cancers. 

Does 5-HTP make you sleepy?

Taking 5-HTP leads to increased serotonin levels in the body. Serotonin can be converted into the hormone melatonin, which plays a vital role in sleep regulation. By increasing melatonin production in the body, 5-HTP can cause drowsiness and promote sleep. Supplements containing a combination of 5-HTP and another neurotransmitter called gamma-aminobutyric acid (GABA) have been found to significantly decrease the time it takes to fall asleep and improve sleep duration and sleep quality. 

Is 5-HTP or melatonin better for sleep?

For people with sleep disorders, either a 5-HTP or melatonin supplement may be helpful. 5-HTP is a melatonin precursor, meaning your body uses it to produce melatonin. Even though it is generally safe to take melatonin with 5-HTP, 5-HTP may interact with other medications; therefore, always talk to your doctor first to see what they might recommend. In many cases, they’d suggest taking both together. 

Melatonin regulates the body’s circadian rhythms while synchronizing the sleep-wake cycle throughout the day. Functional, appropriate levels of melatonin promote consistent, quality sleep. Even though there is no official recommended dosage for melatonin, doses of melatonin in the range of 1 mg to 5 mg are appropriate for most adults to help promote good sleep quality and normal circadian rhythms (sleep-wake cycles). 

Compared to melatonin, which nearly has an immediate effect, it may take 6 to 12 weeks for 5-HTP to be fully effective as a sleep supplement. Researchers recommend 200 to 400 mg at night to stimulate serotonin, which leads to melatonin production. Keep in mind that the 5-HTP dosage will change depending on why you’re taking it. You should ask your doctor or pharmacist for their recommendation of 5-HTP dosage for you.    

Should I take 5-HTP every day?

You should get professional medical advice from a healthcare provider before starting 5-HTP. An appropriate dose of this supplement is usually safe for most people. Studies about the role of 5-HTP and depression were distributing 5-HTP 200 to 300 mg per day, divided into 3 to 4 doses to alleviate nausea and other gastrointestinal side effects.  However, your provider will tell you your recommended dosing, considering the condition being treated, your medical history, and your concurrent medications. Pregnant women should consult their physician before taking 5-HTP or any supplement in general. Currently, there is no data regarding the safety and efficacy of 5-HTP in pregnant women and women who are breastfeeding. 

Why was 5-HTP banned?

Tryptophan supplements were banned in 1989 when they were found to contain a contaminant called Peak X. An outbreak of eosinophilia-myalgia syndrome (EMS) was potentially linked to the contaminated products. As a result, the U.S. Food and Drug Administration (FDA) pulled all tryptophan supplements off the market. Since then, Peak X has also been found in some 5-hydroxytryptophan supplements. There have even been some reports of EMS linked to taking 5-HTP. However, 5-HTP supplements do not contain Peak X in high enough quantities to cause any adverse reactions unless you take very high doses. In any case, it is always a good idea to talk to your healthcare professional before taking 5-HTP or any supplement. If you do decide to take 5-HTP, make sure you purchase a supplement made by a reputable manufacturer. 


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