Initially Posted: 07/27/2018 | Last Updated: 01/19/2019
L-Tryptophan and 5-HTP (5-Hydroxy-L-tryptophan) Supplements Reviewed By

Alphabetical list of 5-hydroxy-L-tryptophan (5-HTP) and L-tryptophan supplement brands compared in this review


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

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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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