Get full access to Outside Learn, our online education hub featuring in-depth nutrition, fitness and adventure courses, and more than 2,000 instructional videos when you sign up for Outside+..
Studies have found that two different supplements can lower blood pressure over time:
Black raspberry powder: 312 mg daily for 8 weeks
Grapeseed extract: 300 mg daily for 6 weeks
Both supplements appear to have a dilating effect on blood vessels. Other studies have found that garlic supplements, flax seeds, and blueberries also help keep blood pressure in line.