Reviewed on 9/16/2021

What Is L-tryptophan Used For?

L-tryptophan is an amino acid used for depression. It may also be used for insomnia, sleep apnea, anxiety, facial pain, a severe form of premenstrual syndrome called premenstrual dysphoric disorder (PMDD), smoking cessation, grinding teeth during sleep (bruxism), attention deficit-hyperactivity disorder (ADHD), Tourette's syndrome, and to improve athletic performance.

L-tryptophan is available under the following different brand names: tryptophan.


Depression is a(n) __________ . See Answer

Dosages for L-tryptophan?

Dosages of L-tryptophan:

8-12 g/day orally divided three to four times daily

Dosage Considerations – Should be Given as Follows:


8-12 g/day orally divided three to four times daily

Lower dosage effective in combination with other antidepressants

Administration: Take with low-protein, carbohydrate-rich meals or snacks

Pediatric: Safety and efficacy not established

What Are Side Effects Associated with Using L-tryptophan?

Side effects of L-tryptophan include:

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with L-tryptophan?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

  • L-tryptophan has no known severe interactions with other drugs.
  • Serious interactions of L-tryptophan include:
  • L-tryptophan has moderate interactions with at least 57 different drugs.
  • L-tryptophan has no known mild interactions with other drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

What Are Warnings and Precautions for L-tryptophan?


This medication contains L-tryptophan. Do not take tryptophan if you are allergic to L-tryptophan or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


Documented hypersensitivity

Effects of Drug Abuse

No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using L-tryptophan?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using L-tryptophan?"


Pregnancy and Lactation

Use L-tryptophan with caution during pregnancy if benefits outweigh risks. Animal studies show risk and human studies are not available or neither animal nor human studies were done.

Avoid use of L-tryptophan during breastfeeding.


Learn to Spot Depression: Symptoms, Warning Signs, Medication See Slideshow

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