Characterization of ingredients present in thermogenic and weight loss supplements

Dietary supplements with label or packaging references to thermogenesis, fat burn, weight loss, or similar terms contain poorly documented ingredient identities. The 98 US products contained 337 ingredients that were divided into six categories using manufacturer product labeling and indicated quantities. There were 135 different raw plant or plant extract ingredients, with 22 present in three or more products, and green tea (521 ± 1,334 mg) being most common in 32 products. There were 49 small molecule isolates, with 11 in three or more products, with caffeine (181 ± 59 mg) being the most common in 36 products. There were 14 minerals, with 10 in three or more products, and chromium (268 ± 282 mg) being most common in 12 products. There were 13 vitamins, with 10 in three or more products, and cobalamin (49 ± 78 µg) being most common in 15 products. Amino acid and lipid categories were also identified with under 10 ingredients in each class. Ingredients described as proprietary, formulas, or blends were present in 44 of the 98 products. Thermogenic and weight loss supplement ingredients are very heterogeneous, complicating clinical understanding of their efficacy or safety for use in the USA or global marketplace.