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What is it?

5-hydroxytryptophan (5-HTP) can be converted to serotonin in the body. It is often used for depression. It has less evidence for insomnia and anxiety.

5-HTP is a chemical byproduct of the protein building block L-tryptophan. It is produced commercially from the seeds of an African plant known as Griffonia simplicifolia. 5-HTP works in the brain and central nervous system by increasing the production of the chemical serotonin. Serotonin can affect sleep, appetite, temperature, sexual behavior, and pain sensation.

Since 5-HTP increases serotonin levels, it is used for conditions in which serotonin is believed to play an important role. These include depression, anxiety, and many other conditions, but there is no good scientific evidence to support most of these uses.

How effective is it?

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for 5-HTP are as follows:

Possibly effective for...

  • Depression. Taking 5-HTP by mouth seems to improve symptoms of depression in some people. It might work as well as some prescription antidepressant drugs.

Possibly ineffective for...

  • Down syndrome. Most research shows that taking 5-HTP by mouth does not improve muscle strength or development in children with Down syndrome.
There is interest in using 5-HTP for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Is it safe?

When taken by mouth: It is possibly safe to take 5-HTP in doses of up to 400 mg daily for up to one year. The most common side effects include heartburn, stomach pain, nausea, vomiting, diarrhea, drowsiness, sexual problems, and muscle problems. Large doses of 5-HTP, such as 6-10 grams daily, are possibly unsafe. These doses have been linked to severe stomach problems and muscle spasms.

Some people who have taken 5-HTP have developed a serious health condition called eosinophilia-myalgia syndrome (EMS). Some people think EMS might be caused by an accidental contaminant in some 5-HTP products. But there's not enough scientific evidence to know if EMS is caused by 5-HTP, a contaminant, or some other factor. Until more is known, 5-HTP should be used cautiously.

Special precautions & warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if 5-HTP is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.

Children: It is possibly safe for children to take 5-HTP by mouth at appropriate doses. In children under 12 years of age, 5-HTP seems to be safe at a dose of up to 5 mg/kg daily for up to 3 years.

Surgery: 5-HTP can affect a brain chemical called serotonin. Some drugs administered during surgery can also affect serotonin. Taking 5-HTP before surgery might cause too much serotonin in the brain and can result in serious side effects including heart problems, shivering, and anxiety. Tell patients to stop taking 5-HTP at least 2 weeks before surgery.

Are there interactions with medications?

Be cautious with this combination.
Carbidopa (Lodosyn)
5-HTP can affect the brain. Carbidopa can also affect the brain. Taking 5-HTP along with carbidopa can increase the risk of serious side effects including rapid speech, anxiety, aggressiveness, and others.
Sedative medications (CNS depressants)
5-HTP might cause sleepiness and slowed breathing. Some medications, called sedatives, can also cause sleepiness and slowed breathing. Taking 5-HTP with sedative medications might cause breathing problems and/or too much sleepiness.
Serotonergic drugs
5-HTP might increase a brain chemical called serotonin. Some medications also have this effect. Taking 5-HTP along with these medications might increase serotonin too much. This might cause serious side effects including heart problems, seizures, and vomiting.

Are there interactions with herbs and supplements?

Herbs and supplements with sedative properties
5-HTP might cause sleepiness and slowed breathing. Taking it along with other supplements with similar effects might cause too much sleepiness and/or slowed breathing in some people. Examples of supplements with this effect include hops, kava, L-tryptophan, melatonin, and valerian.
Herbs and supplements with serotonergic properties
5-HTP increases a brain chemical called serotonin. Taking it along with other supplements that have this effect might cause serious side effects, including heart problems, seizures, and vomiting. Examples of supplements with this effect include black seed, L-tryptophan, SAMe, and St. John's wort.

Are there interactions with foods?

There are no known interactions with foods.

How is it typically used?

5-HTP has most often been used by adults in doses of 150-800 mg daily. Very large doses of 5-HTP, such as 6-10 grams daily, can cause serious side effects and should be avoided. Speak with a healthcare provider to find out what dose might be best for a specific condition.

Other names

2-Amino-3-(5-Hydroxy-1H-Indol-3-yl) Propanoic Acid, 5 Hydroxy-Tryptophan, 5 Hydroxy-Tryptophane, 5-Hydroxytryptophan, 5-Hydroxytryptophane, 5-Hydroxy L-Tryptophan, 5-Hydroxy L-Tryptophane, 5-Hydroxy Tryptophan, 5-L-Hydroxytryptophan, L-5 HTP, L-5-Hydroxytryptophan, L-5-Hydroxytryptophane, Oxitriptan.


To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.


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Last reviewed - 09/15/2023