5-Hydroxytryptophan (HTP) Side Effects and Benefits

Richard N. Fogoros, MD, is a retired professor of medicine and board-certified internal medicine physician and cardiologist. He is Verywell's Senior Medical Advisor.

If you're considering the use of 5-HTP supplements, talk with your primary care provider first. Self-treating a condition and avoiding or delaying standard care may have serious consequences. Curcumin In Food

5-Hydroxytryptophan (HTP) Side Effects and Benefits

5-HTP is a substance that is sometimes used as a supplement. It can be converted in the body to serotonin, which has led to an interest in its use to treat depression, anxiety, insomnia, and some other conditions.

This article discusses what 5-HTP is, how it is used, and research on its potential effects. It also covers some of the potential side effects and drug interactions that may occur.

5-Hydroxytryptophan (5-HTP) is a compound produced in the body from the amino acid tryptophan. It is a precursor to the neurotransmitter serotonin and the hormone melatonin.

5-HTP is manufactured from the seeds of an African plant, Griffonia simplicifolia. The supplements have become popular because it is thought that providing the body with 5-HTP in pill form can boost the body's serotonin levels, similar to the antidepressants that are thought to increase the amount of serotonin available to the brain.

Serotonin is a type of neurotransmitter that carries signals between nerve cells in the brain. It helps to regulate a variety of functions in the body, including attention, behavior, and mood. By increasing serotonin levels in the brain, mood can often improve.

In alternative medicine, 5-hydroxytryptophan supplements are purported to help in the treatment of conditions including:

However, it is important to note that support for the claim that 5-HTP can treat any condition safely and effectively is lacking. More research is needed before this supplement can be recommended as a potential treatment for any condition.

Here's a look at some of the research studies so far.

Several small clinical trials have found that 5-HTP may be as effective as antidepressants. For example, in a six-week clinical trial, 63 people were given either 5-HTP (100 mg three times a day) or an antidepressant (fluvoxamine, 50 mg three times a day). The 5-HTP was found to be as effective as the antidepressant, with fewer side effects.

However, one systematic review of studies published between 1966 to 2000 found that only one out of 108 studies met the quality standards. The small study that did meet the quality criteria found that 5-HTP worked better than a placebo at alleviating depression.

Other research suggests that the antidepressant effects of 5-hydroxytryptophan may be most beneficial when used to augment other depression medications. A 2017 study found that a combination of creatine and 5-HTP was effective when used to augment SSRI or SNRI antidepressants in women who were experiencing treatment-resistant depression.

Never take 5-HTP if you are currently taking other medications, supplements, or substances without consulting your doctor first. Potentially dangerous drug interactions may occur.

Serotonin is converted into melatonin, a hormone needed to regulate sleep-wake cycles. Because 5-HTP is thought to increase serotonin levels, it may increase melatonin and help normalize sleep patterns.

A 2021 clinical trial found that supplementation with 5-HTP improved sleep latency for eight weeks among older adults. However, such effects were not observed over a prolonged period, possibly due to the body acclimating the long-term 5-hydroxytryptophan supplementation.

Some older research indicates that 5-HTP may be beneficial in the treatment of other conditions including migraines and fibromyalgia. Newer, higher-quality research is needed.

While side effects can occur, they are often mild. Potential side effects of 5-HTP include:

One older study found that such side effects are dose-dependent. In other words, they are worse the more of the supplement you take.

Rarely, an allergic reaction to the supplement may occur. Symptoms of an allergic reaction may include skin rash, hives, or swelling of the tongue, lips, or throat. A severe allergic reaction may result in anaphylaxis. If you experience any of these symptoms, seek medical attention immediately.

In 1998, the Food and Drug Administration (FDA) reported having detected a chemical compound known as "peak x" in some 5-HTP products. Peak x had been previously associated with the supplement tryptophan, which is made into 5-HTP in the body.

Tryptophan was taken off the market when thousands of people developed a severe blood disorder called Eosinophilia-Myalgia Syndrome (EMS) due to the way the product was manufactured. Some reports suggest that purity may be a potential problem for 5-HTP as well. No cases of EMS resulting from 5-HTP use have been reported, however.

Children with Down's syndrome should not take 5-HTP. Individuals who have high blood pressure or diabetes should consult a healthcare professional before taking 5-HTP. It should also not be taken by people who are currently taking an antidepressant or who have liver disease.

Some of the drugs that may potentially interact with 5-HTP supplements include:

These medications elevate serotonin levels. When combined with 5-HTP, they can increase the risk of experiencing serotonin syndrome. Symptoms of serotonin syndrome include high blood pressure, poor coordination, rapid breathing, and tremors. In severe cases, people may experience high fever, loss of consciousness, rapid changes in blood pressure/heart rate, and seizures.

If you or someone you know experiences such symptoms, go to the emergency room or call 911 immediately.

There is not enough scientific data to provide a recommended dose of 5-HTP. However, in scientific studies, a dose of 150-800 mg daily is commonly taken for 2-6 weeks in the treatment of depression. Less commonly, higher doses are used.

The appropriate dose for you may depend on factors including your age, gender, and medical history. Speak to your healthcare provider to get personalized advice.

You can boost your dietary intake of L-tryptophan, which the body converts to 5-HTP. Food sources of L-tryptophan include:

5-HTP supplements are found in health food stores, online, and at some drug stores. Be careful not to confuse 5-HTP with 5-hydroxytryptamine (5-HT), the chemical name for the neurotransmitter serotonin.

Always exercise caution when buying this or any supplement. Supplements haven't been tested for safety and due to the fact that dietary supplements are largely unregulated, the content of some products may differ from what is specified on the product label.

Also keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established.

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5-Hydroxytryptophan (HTP) Side Effects and Benefits

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