BoneScience Blog — Kaempferia parviflora

Two black ginger bottles can both say 500 mg and contain different things. Seven checks on the back label: extract versus powder, the flavone percentages, which extracts were tested in people, proprietary blends, the Latin name, the certificate of analysis and the fine print.

Sirtmax® is a branded black ginger extract from Tokiwa Phytochemical in Japan, standardized to 15% polymethoxyflavones. One 12-week randomized trial gave 100 mg a day to adults with overweight. Here are its numbers, its limits, and three label checks.

Black ginger has about ten human trials. Three 12-week trials measured less body fat than placebo, two measured a stronger grip, a single dose did nothing, and no trial ran longer than 12 weeks. Here is each one, plus the doses and what is still unknown.