Benefits
Antioxidant defense
Grape seed OPCs are polyphenols that show antioxidant activity in laboratory assays. The single human trial cited on this page did not measure antioxidant status or oxidative-stress markers, so this describes a proposed mechanism rather than a demonstrated outcome in people.
Blood pressure — one pilot finding
In the single cited pilot trial, both grape seed proanthocyanidin doses were associated with lower blood pressure in middle-aged women. Broader claims about blood-vessel function and circulation come from the wider grape seed polyphenol literature, which is not cited here and has not been demonstrated for Vitaflavan® specifically.
Menopausal support
In one randomized, double-blind, placebo-controlled pilot trial (Terauchi 2014; n=96 enrolled, 91 completed), middle-aged women took 100 or 200 mg/day of a grape seed proanthocyanidin extract or placebo. The higher dose improved physical-symptom, hot-flash and insomnia scores; both doses reduced anxiety scores and blood pressure, and muscle mass increased. This is a single pilot study, and the extract tested was not identified as Vitaflavan®.
Mechanism of action
Proanthocyanidin antioxidant action
In laboratory studies, OPCs neutralize free radicals and influence antioxidant enzyme activity. This is a proposed mechanism; the human pilot trial cited on this page did not measure antioxidant or oxidative-stress endpoints.
Endothelial support
Grape seed polyphenols have been reported to influence nitric-oxide-mediated blood-vessel relaxation in preclinical and general grape seed research. No study cited on this page tested this mechanism, and it has not been shown for Vitaflavan® specifically.
Clinical trials
Randomized, double-blind, placebo-controlled PILOT trial of 100 or 200 mg/day grape seed proanthocyanidin extract on menopausal symptoms, body composition and cardiovascular parameters; n=96 enrolled, 91 completed. The product was described as grape seed extract tablets and is not identified in the paper as Vitaflavan®. (Terauchi et al. 2014, Menopause)
Middle-aged women; 96 randomized, 91 completed.
The 200 mg/day dose improved physical-symptom, hot-flash and insomnia scores versus placebo; both the 100 and 200 mg/day doses reduced anxiety scores and blood pressure, and muscle mass increased. These are pilot-study results in a small sample and need confirmation in a larger trial of the branded extract.