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Labdoor analyzed 9 of the best-selling biotin supplements in the United States for biotin content and heavy metal (arsenic, cadmium, lead, mercury) contamination.

Overall, biotin measurements in this batch analysis ranged from 571 mcg to 10700 mcg per serving, deviating from label claims by an average of 14%. 2 out of every 3 products recorded less biotin than claimed, with one product recording as little as 57% of its label claim for biotin. All products passed heavy metal screenings.

For the US population, biotin deficiency is rare, but can lead to skin rash, hair loss, high cholesterol, and heart problems. To prevent deficiencies, the Adequate Intake (AI) per day for biotin has been defined as 30 mcg for most adults and 35 mcg for breastfeeding women. Claims that biotin intake above this level is effective for treating acne, eczema, and hair loss have not been proven1. Currently, biotin does not have an established Tolerable Upper Intake Level (UL) as reports of side effects are limited. Biotin has been found to be safe even at doses of up to 10000 mcg per day2.

Analytical Chemistry Methods: LC-UVDAD (biotin); ICP-MS (arsenic, cadmium, lead, mercury).



Half of the tested products measured biotin underages of 10% or more compared to product label claims.

Measured biotin in this batch analysis deviated from label claims by an average of 14%. 6 of the 9 products measured less biotin than claimed, recording an average underage of 19%. In Vitafusion Biotin, measured biotin was 43% less than its respective label claim.



All 9 products passed heavy metal screens for arsenic, cadmium, lead, and mercury.

All products passed heavy metal screens. This means that each product's heavy metal recordings per serving fell below California Proposition 65's3 proposed and established MADLs (Maximum Allowable Dose Levels) and NSRLs (No Significant Risk Levels): no more than 10 mcgday of inorganic arsenic, 4.1 mcgday of cadmium, 0.5 mcgday of lead, and 0.3 mcgday of mercury (proposed).



Biotin products averaged a 99.9 (out of 100) in Nutritional Value scores.

Biotin products in this batch recorded minimal quantities of calories, fats, carbohydrates, and sugars.



No flagged artificial sweeteners, colors, or preservatives were recorded in this batch analysis.

Biotin currently does not have an established safe upper limit as reports of side effects are rare. The NIH reports that no side effects have been reported for biotin in amounts up to 10000 mcg per day2. 2 of the 9 products measured more than 10000 mcg of biotin per serving. High doses of biotin have been associated with acne breakouts. Biotin can also interact with certain medications1. Please consult your physician before supplementation, especially if you have a medical condition, are pregnant, or are taking any other drugs or dietary supplements.

No synthetic sweeteners, artificial colors, or controversial preservatives were recorded in this batch.



On average, products measured 5374 mcg of biotin per serving.

Biotin content averaged 5374 mcg per serving, ranging from 517 mcg in Vitafusion Biotin to 10700 mcg in Natrol Biotin Maximum Strength. Serving sizes are not standardized. 6 products recorded less than 5000 mcg of biotin per serving. 2 products recorded more than 10000 mcg of biotin per serving.

Biotin, also known as Vitamin H, is used by the body to process carbohydrates, fats, and amino acids. Although very rare, deficiencies in biotin can lead to hair loss, skin rashes, high cholesterol, heart problems, and generalized fatigue. The established Adequate Intake (AI) for biotin to prevent deficiencies is 30 mcg per day for most adults and 35 mcg per day for breastfeeding women. Biotin supplementation may be helpful for controlling blood sugar levels in diabetics and improving symptoms of diabetic neuropathy. Biotin supplements are also often taken to strengthen hair and nails, although research has not shown biotin intake above the AI to be effective for this purpose1. Please consult a physician for specific dosing.



  • 1 University of Maryland Medical Center. (2013). Vitamin H (Biotin).
  • 2 Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes and its Panel on Folate, Other B Vitamins, and Choline. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline.
  • 3 CA OEHHA. (2016). Proposition 65.