Repeat dose study of the cancer chemopreventive agent resveratrol in healthy volunteers: safety, pharmacokinetics, and effect on the insulin-like growth factor axis

Brown VA, Patel KR, Viskaduraki M, Crowell JA, Perloff M, Booth TD · Cancer Research

The definitive human dosing study. Resveratrol was safe overall, but 2.5 g and 5 g daily caused mild to moderate gastrointestinal symptoms. Sulfate and glucuronide metabolites reached areas under the curve up to 20.3-fold higher than parent resveratrol. Circulating IGF-1 and IGFBP-3 fell (p<0.04 for both), most markedly at 2.5 g.

Population

Healthy volunteers

Intervention

Resveratrol 0.5, 1.0, 2.5 or 5.0 g daily for 29 days

Comparator

Dose comparison

Limitations

Twenty-nine days in healthy volunteers; no placebo arm for the IGF-1 comparison. Establishes where gastrointestinal tolerance breaks down — well above the 500 mg supplement dose — and confirms that the conjugates, not free resveratrol, dominate exposure.