Health Guide


What is it?

Tryptophan is an herbal medicine/supplement used to help you sleep and to treat depression.

Other names for tryptophan include: L-tryptophan.

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement)
  • are pregnant or plan to become pregnant while using this medicine
  • are breastfeeding
  • have any other health problems, such as high blood pressure or heart or blood vessel disease


Talk with your caregiver about how much tryptophan you should take. The amount depends on the strength of the medicine and the reason you are taking tryptophan. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.

Drug and Food Interactions:

Do not take tryptophan without talking to your doctor first if you are taking:

  • Medicines called SSRIs used to treat depression (examples: duloxetine (Cymbalta(R)); fluoxetine (Prozac(R)); fluvoxamine (Luvox(R)); paroxetine (Paxil(R))) (2-5)
  • Medicines called MAOIs used to treat depression (examples: clorgyline; isocarboxazid (Marplan(R)); phenelzine (Nardil(R)); selegiline (Emsam(R)); tranylcypromine (Parnate(R))) (6-11)
  • sibutramine (Meridia(R)) (12)
  • Medicines used to treat a condition called fibromyalgia, which causes muscle pain and stiffness. This medicine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI) (example: milnacipran (Savella(R))) (13)


  • Before taking tryptophan, tell your doctor if you are pregnant or breastfeeding

Side Effects:

Call your doctor right away if you have any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hand, swelling or tingling in your mouth or throat, chest tightness, trouble breathing, or rash.
  • Serotonin syndrome: Agitation or confusion, facial flushing, fever, diarrhea, muscle spasms and tremor (1).

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • Dizziness, drowsiness (1)
  • Dry mouth, loss of appetite (1)


1. Product Information: Alti-Tryptophan(R), L-tryptophan. AltiMed Pharmaceutical Company, Mississauga, Ontario, Canada, May 1999.

2. Product Information: CYMBALTA(R) delayed-release oral capsules, duloxetine hydrochloride. Eli Lilly and Company, Indianapolis, IN, 2008.

3. Product Information: PROZAC(R) oral capsules, delayed-release capsules, solution, fluoxetine oral capsules, delayed-release capsules, solution. Eli Lilly and Company, Indianapolis, IN, 2007.

4. Product Information: Luvox(R), fluvoxamine. Solvay Pharmaceuticals, Marietta, GA, 1998.

5. Product Information: Paxil(R), paroxetine hydrochloride. GlaxoSmithKline, Research Triangle Park, NC, 2004.

6. Pope HG Jr, Jonas JM, Hudson JI, et al: Toxic reactions to the combination of monoamine oxidase inhibitors and tryptophan. Am J Psychiatry 1985; 142:491-492.

7. Levy AB, Bucher P, & Votolato N: Myoclonus, hyperreflexia and diaphoresis in patients on phenelzine-tryptophan combination treatment. Can J Psychiatry 1985; 30:434-436.

8. Product Information: Marplan(R), isocarboxazid. Roche Laboratories, Nutley, NJ, 1999.

9. Product Information: Nardil(R), phenelzine. Parke-Davis, Morris Plains, NJ, 1997.

10. Sternbach H: The serotonin syndrome. Am J Psychiatry 1991; 148:705-713.

11. Product Information: Parnate(R) oral tablets, tranylcypromine sulfate oral tablets. GlaxoSmithKline, Research Triangle Park, NC, 2007.

12. Product Information: Meridia(R), sibutramine. Abbott Laboratories, North Chicago, IL, 2003.

13. Product Information: Savella(R) oral tablets, milnacipran HCL oral tablets. Forest Pharmaceuticals, St Louis, MO, 2009.

Last Updated: 7/4/2018
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