L-Tryptophan and 5-Hydroxytryptophan (5-HTP) Supplements
HOW PRODUCTS WERE EVALUATED:
How Products were Selected:
Products tested represent those commonly sold and/or available nationally in the U.S. ConsumerLab.com purchased products on the open market through retail stores, on-line retailers, and direct sales or multi-level marketing companies. Products were not accepted directly from manufacturers.
5-HTP containing products were analyzed in one or more independent laboratories for the following:
- Quantification of 5-HTP and L-tryptophan by High Performance Liquid Chromatography (HPLC).
- Quantification of total impurities before and after 5-HTP or L-tryptophan by HPLC.
- Quantitative analyses of lead, cadmium and arsenic by ICP/MS.
- Disintegration of non-chewable, non-capsule and non-time released formulations utilizing United States Pharmacopeia (USP) () <2040> recommendations entitled "Disintegration and Dissolution of Nutritional Supplements."
Any products not passing testing was sent to another independent laboratory to repeat testing for criterion on which it did not pass.
ConsumerLab.com may modify or use other appropriate test methods if necessary to test special product formulations.
Identities of the products were not disclosed to laboratories performing the testing.
To achieve a "Pass" in the testing, a product had to meet the following criteria:
* Passing scores allow for specific margins of technical error associated with each analysis. ConsumerLab.com reserves the right to disqualify a product at any time from passing its testing if it considers such product to present a safety risk or to provide misleading or inaccurate information in its labeling.
- Contain no less than 100% and no more than 130% of label claim for 5-HTP or L-tryptophan.
- Contain a maximum of 0.01% total impurities eluting before 5-hydroxy-L-tryptophan or L-tryptophan and maximum 0.03% total impurities eluting after 5-hydroxy-L-tryptophan or L-tryptophan. Maximum 0.5% tryptophan in 5-HTP supplements. (USP 40).
- Heavy Metals: Products must not exceed the following limits:
- Products marketed for use by children may not exceed the State of California's Prop 65 limits for lead in dietary supplements of 0.5 mcg per recommended daily serving with an additional allowance of 0.8 mcg if the product contains more than 1,000 mg/day of calcium.
- Products with a single serving weights of less than 5 grams which are not marketed for use by children, may not exceed the State of California's Prop 65 limits for lead in dietary supplements of 0.5 mcg per recommended daily serving with an additional allowance of 0.4 mcg if containing 250-999 mg/day of any combination of elemental calcium, magnesium and potassium or 0.8 mcg if containing more than 1,000 mg/day of any combination of these minerals. An additional allowance of 0.5 mcg is provided if containing 250-999 mg/day of whole herb (not extract) or 1.0 mcg if containing 1000 mg/day or more of whole herb (not extract). However, total lead allowance will not exceed 2 mcg.
- Products with single serving weights of 5 grams or more which are not marketed for children may not exceed 2.5 mcg per serving nor 4.0 mcg per daily serving.
- If marketed for use by children, may not exceed 3.0 micrograms of cadmium per recommended daily serving (based on Canada's limit for a child weighing 75lbs). If not marketed for use by children, may not exceed 4.1 micrograms of cadmium per recommended daily serving (based on the State of California's Prop 65 limit).
- Contain less than 10 micrograms of total arsenic and no more than 5 micrograms of inorganic arsenic per daily serving (EPA and state of New Jersey limits - based on 1 liter of water.
- If applicable to the product, it must meet recommended USP <2040> parameters of disintegration for dietary supplements (excluding capsule, chewable and time-release products).
- Be in compliance with FDA labeling requirements.
** Based on state of California Prop 65 limits. California requires supplements exceeding this limit to bear a warning label.
ConsumerLab.com reserves the right to disqualify a product at any time from passing its testing if it considers such product to present a safety risk or to provide misleading or inaccurate information in its labeling.
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