To assess the effects of Rhodiola rosea on a mouse model of T2D, we treated a cohort of 6 week-old leptin receptor-knockout (db/db) mice with an extract of R. rosea that was verified for quality based on validated biomarkers (see “Methods”), administered daily at a dose of 25 mg/kg by oral gavage for 4 weeks. This evidence concerns the gene LEPR and type 2 diabetes mellitus.