Product Reviews
L-Tryptophan and 5-Hydroxytryptophan (5-HTP) Supplements

Reviewed and edited by Tod Cooperman, M.D. Tod Cooperman, M.D.
 Initial Posting: 7/27/18   Last Update: 1/19/19
L-Tryptophan and 5-HTP (5-Hydroxy-L-tryptophan) Supplements Reviewed By

Choose the Best L-Tryptophan and 5-HTP Supplements

CL Tests Identify High Quality L-Tryptophan and 5-HTP (5-Hydroxy-L-Tryptophan) at the Best Value

Alphabetical list of 5-hydroxy-L-tryptophan (5-HTP) and L-tryptophan supplement brands compared in this review
BioScience Nutrition 5-HTP Finest Nutrition [Walgreens] 5-HTP Natural Factors 5-HTP
Doctor's Best Best L-Tryptophan With TryptoPure Natrol 5-HTP Swanson Ultra L-Tryptophan TryptoPure
BioScience Nutrition 5-HTP Doctor's Best Best L-Tryptophan With TryptoPure Finest Nutrition [Walgreens] 5-HTP Natrol 5-HTP Natural Factors 5-HTP Swanson Ultra L-Tryptophan TryptoPure
Make sure the L-tryptophan or 5-HTP or supplement you take passed our tests. Isn't your health worth it?
L-tryptophan supplements are often promoted to improve sleep and mood, and 5-HTP supplements to help with depression. But there have been reports in the past of serious illness (eosinophilia-myalgia syndrome or EMS) associated with the use of certain L-tryptophan supplements, and even 5-HTP.

So, do L-tryptophan and 5-HTP supplements really work, and are they safe to use? And which products are best?  

To find out, recently tested popular L-tryptophan and 5-HTP supplements, carefully checking them to see if they contained their listed amounts of L-tryptophan or 5-HTP and whether they were contaminated with heavy metals or chemical impurities. We also reviewed the clinical evidence for and against L-tryptophan and 5-HTP. 

We identified a number of high-quality products. Among these we identified two that provide the best value (because L-tryptophan and 5-HTP especially can be expensive) — making them our Top Picks.

You must be a member to get the full test results along with's Top Picks. You'll get results for six supplements: five selected by and one other product that passed the same testing in our voluntary Quality Certification Program. In the review, you'll learn:
    • ConsumerLab's Top Picks for L-tryptophan and 5-Hydroxy-L-tryptophan (5-HTP) supplements based on quality, dose and value  
    • Which products passed or failed our tests and why
    • How L-tryptophan and 5-HTP supplements compare on ingredients, dosage, and cost
    • Information about branded L-tryptophan ingredients (such as TryptoPure) and what to look for on the label when choosing an L-tryptophan or 5-HTP supplement
    • Dosage of L-tryptophan and 5-HTP for specific uses and the evidence for or against those uses (including sleep, depression, migraine, weight loss, and fibromyalgia)
    • Safety concerns, including information about eosinophilia-myalgia syndrome (EMS) associated with use of L-tryptophan and 5-HTP supplements, as well as potential side effects and drug interactions

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Learn more about L-Tryptophan and 5-HTP Supplements Answers -- for L-Tryptophan and 5-Hydroxytryptophan (5-HTP) Supplements
I take fluoxetine (Prozac), a SSRI drug to treat depression. Are there supplements I should avoid, or be taking, due to this drug? Get the answer >>

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Which supplements can cause diarrhea? Get the answer >>
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