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From the National Institutes of HealthNational Institutes of Health

5-HTP


What is it?

5-HTP (5-Hydroxytryptophan) is a chemical by-product of the protein building block L-tryptophan. It is also produced commercially from the seeds of an African plant (Griffonia simplicifolia).

Don’t use 5-HTP until more is known. 5-HTP might be UNSAFE. Some people who have taken it have come down with eosinophilia-myalgia syndrome (EMS), a serious condition involving extreme muscle tenderness (myalgia) and blood abnormalities (eosinophilia). Some people think the EMS might be caused by an accidental ingredient (contaminant) in some 5-HTP products. But there is not enough scientific evidence to know if EMS is caused by 5-HTP, a contaminant, or some other factor. Until more is known, avoid taking 5-HTP.

5-HTP is used for sleep disorders, depression, anxiety, migraine and tension-type headaches, fibromyalgia, binge eating associated with obesity, premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD), attention deficit-hyperactivity disorder (ADHD), and along with prescription drugs to treat seizure disorder and Parkinson's disease.

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. There is some evidence that 5-HTP might be about as effective as some prescription drugs for depression.
  • Fibromyalgia. Taking 5-HTP by mouth appears to improve symptoms of fibromyalgia including pain severity, morning stiffness, and sleeplessness.

Possibly ineffective for...

  • Tension headaches. Taking 5-HTP doesn’t seem to reduce pain or the number of headaches suffered by people with chronic tension-type headaches.

Insufficient evidence to rate effectiveness for...

  • Alzheimer's disease. Early studies suggest that 5-HTP doesn’t help symptoms of Alzheimer’s disease.
  • Anxiety. There is some evidence suggesting that 5-HTP might reduce symptoms of anxiety disorders.
  • Weight loss and obesity. Preliminary evidence suggests that taking 5-HTP might help reduce appetite, caloric intake, and weight in obese people.
  • Premenstrual syndrome (PMS).
  • Premenstrual dysphoric disorder (PMDD).
  • Attention deficit-hyperactivity disorder (ADHD).
  • Sleep disorders.
  • Other conditions.
More evidence is needed to rate the effectiveness of 5-HTP for these uses.

How does it work?

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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 the synthesis of serotonin, it is used for several diseases where serotonin is believed to play an important role including depression, insomnia, obesity, and many other conditions.

Are there safety concerns?

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5-HTP is POSSIBLY UNSAFE for use. There is concern that it can cause a serious side effect called eosinophilia myalgia syndrome. Some people think this side effect is only caused by a contaminant in some 5-HTP products; but there is not enough scientific evidence to know if it is caused by 5-HTP, a contaminant, or some other factor. Until more is known, 5-HTP should be avoided.

Other potential side effects of 5-HTP include heartburn, stomach pain, nausea, vomiting, diarrhea, drowsiness, sexual problems, and muscle problems.

Special precautions & warnings:

Pregnancy and breast-feeding: 5-HTP is POSSIBLY UNSAFE in pregnancy and breast-feeding. Avoid using it.

Down syndrome: There are reports of 5-HTP causing seizures in some people with Down syndrome. In one group studied, 15% of people with Down syndrome receiving long-term 5-HTP treatment experienced seizures.

Are there interactions with medications?

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Major

Do not take this combination.

Medications for depression (Antidepressant drugs)
5-HTP increases a brain chemical called serotonin. Some medications for depression also increase serotonin. Taking 5-HTP along with these medications for depression might increase serotonin too much and cause serious side effects including heart problems, shivering, and anxiety. Do not take 5-HTP if you are taking medications for depression.

Some of these medications for depression include fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft), amitriptyline (Elavil), clomipramine (Anafranil), imipramine (Tofranil), and others.

Medications for depression (MAOIs)
5-HTP increases a chemical in the brain. This chemical is called serotonin. Some medications used for depression also increase serotonin. Taking 5-HTP with these medications used for depression might cause there to be too much serotonin. This could cause serious side effects including heart problems, shivering, and anxiety.

Some of these medications used for depression include phenelzine (Nardil), tranylcypromine (Parnate), and others.

Moderate

Be cautious with this combination.

Carbidopa (Lodosyn)
5-HTP can affect the brain. Carbidopa (Lodosyn) 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.

Dextromethorphan (Robitussin DM, and others)
5-HTP can affect a brain chemical called serotonin. Dextromethorphan (Robitussin DM, others) can also affect serotonin. Taking 5-HTP along with dextromethorphan (Robitussin DM, others) might cause too much serotonin in the brain and can result in serious side effects including heart problems, shivering, and anxiety. Do not take 5-HTP if you are taking dextromethorphan (Robitussin DM, and others).

Meperidine (Demerol)
5-HTP increases a chemical in the brain called serotonin. Meperidine (Demerol) can also increase serotonin in the brain. Taking 5-HTP along with meperidine (Demerol) might cause too much serotonin in the brain and serious side effects including heart problems, shivering, and anxiety.

Pentazocine (Talwin)
5-HTP increases a brain chemical called serotonin. Pentazocine (Talwin) also increases serotonin. Taking 5-HTP along with pentazocine (Talwin) might increase serotonin too much. This could cause serious side effects including heart problems, shivering, and anxiety. Do not take 5-HTP if you are taking pentazocine (Talwin).

Tramadol (Ultram)
Tramadol (Ultram) can affect a chemical in the brain called serotonin. 5-HTP can also affect serotonin. Taking 5-HTP along with tramadol (Ultram) might cause too much serotonin in the brain and might result in side effects including confusion, shivering, stiff muscles, and others.

Are there interactions with herbs and supplements?

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Herbs and supplements with serotonergic properties
5-HTP might increase the effects and side effects of products that increase serotonin levels, including Hawaiian baby woodrose, L-tryptophan, S-adenosylmethionine (SAMe), and St. John's wort.

Are there interactions with foods?

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There are no known interactions with foods.

What dose is used?

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The appropriate dose of 5-HTP depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for 5-HTP. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Other names

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5HTP, 5 HTP, 5 Hydroxy-Tryptophan, 5 Hydroxy-Tryptophane, 5-hydroxytryptophan, 5-Hydroxytryptophane, 5-Hydroxy L-Tryptophan, 5-Hydroxy L-Tryptophane, 5-Hydroxy Tryptophan, 5-Hydroxy Tryptophane, 5-L-Hydroxytryptophan, L-5 HTP, L-5 hydroxytryptophan, L-5 Hydroxytryptophane, Oxitriptan.

Methodology

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To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.methodology (http://www.nlm.nih.gov/medlineplus/druginfo/natural/methodology.html).

References

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To see all references for the 5-HTP page, please go to http://www.nlm.nih.gov/medlineplus/druginfo/natural/794.html.

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  7. Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3.
  8. FDA. Information paper on L-tryptophan and 5-hydroxy-L-tryptophan. Office of Nutritional Products, Labeling, Dietary Supplements. Center for Food Safety and Applied Nutrition. February 2001.
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  10. Ribeiro CA. L-5-Hydroxytryptophan in the prophylaxis of chronic tension-type headache: a double-blind, randomized, placebo-controlled study. Headache 2000;40:451-6.
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  9. Cangiano C, Ceci F, Cancino A, et al. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan. Am J Clin Nutr 1992;56:863-7.
  10. Sarzi Puttini P, Caruso I. Primary fibromyalgia syndrome and 5-hydroxy-L-tryptophan: a 90-day open study. J Int Med Res 1992;20:182-9.
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Last reviewed - 05/04/2011

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Page last updated: 27 September 2012