L-tryptophan (Tryptophan, Tryptan) (cont.)

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PREPARATIONS: L-tryptophan is available in 500 mg and 1000 mg tablets and capsules.

STORAGE: L-tryptophan is stored in tightly closed containers. Due to multiple companies producing this medication, storage requirement may vary based on manufacturer.


  • Adults: Take 8 to 12 grams of L-tryptophan by mouth per day. L-tryptophan should be taken in divided doses of three or four times a day.
  • Pediatric: Safe and effective use in pediatric patients is not determined.

DRUG INTERACTIONS: L-tryptophan should be used with caution with other anti-depressants like citalopram (Celexa), desvenlafaxine (Pristiq), vilazodone, linezolid, and phenelzine because of increased risk of a serious condition called serotonin syndrome caused by excessive serotonin in the brain.

PREGNANCY: There are no adequate studies done on L-tryptophan to determine safe and effective use in pregnant women.

NURSING MOTHERS: It is not known whether L-tryptophan enters breast milk; however, it is best to avoid L-tryptophan during breastfeeding to avoid risk to the newborn.

Medically reviewed by Eni Williams, PharmD


Medically Reviewed by a Doctor on 9/29/2015

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