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White Plains, New York, July 31, 2018 — L-tryptophan supplements are often promoted to improve sleep and 5-HTP supplements to help with depression. However, use of L-tryptophan, as well as that of 5-HTP (5-hydroxytryptophan), has been linked in the past to a serious illness known as eosinophilia-myalgia syndrome, or EMS. So, are L-tryptophan and 5-HTP supplements safe to use and do they really work? And if so, which products on the market are best?

To find out, ConsumerLab recently purchased and tested popular L-tryptophan and 5-HTP supplements sold in the U.S., checking to see if they contained their listed amounts of L-tryptophan or 5-HTP and whether they were contaminated with chemical impurities or heavy metals. ConsumerLab also carefully reviewed the clinical evidence regarding the safety and efficacy of L-tryptophan and 5-HTP. Finally, ConsumerLab compared the cost to obtain equal amounts of L-tryptophan or 5-HTP from the products to determine which among those best in quality also offered the best value.

The findings are available online now in ConsumerLab's L-Tryptophan and 5-HTP Supplements Review, which also discusses the risk of EMS and summarizes the clinical evidence for and against L-tryptophan for sleep, and 5-HTP for depression and other conditions such as migraine and fibromyalgia. The Review also explains dosage, potential side effects and drug interactions, what to look for on labels when choosing a L-tryptophan or 5-HTP supplement, and how L-tryptophan can be obtained through the diet.

The Review includes test results and comparisons for six supplements including five selected for testing by ConsumerLab and one that passed the same testing through CL's voluntary Quality Certification Program. Products covered in the report are: BioScience Nutrition 5-HTP, Doctor's Best Best L-Tryptophan With TryptoPure, Finest Nutrition [Walgreens] 5-HTP, Natrol 5-HTP, Natural Factors 5-HTP, and Swanson Ultra L-Tryptophan TryptoPure. Among these, ConsumerLab identifies its Top Picks.

Founded in 1999, is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. Membership to is available online and provides immediate access to reviews of more than 1,000 products from over 400 brands. The company is privately held and based in Westchester, New York. It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products.

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