Grapeseed extract can also be dangerous for people with bleeding disorders or who are taking blood thinning medications, including warfarin and aspirin.

Arginine (L-arginine) is an amino acid that helps the body make protein. It is found in meat, poultry, fish, eggs, dairy products, and legumes. If you eat a balanced diet that includes these foods, you’ll get around 4 to 5 grams of arginine per day, experts at the Mayo Clinic say. Arginine is converted in the body to nitric oxide, which dilates blood vessels to increase blood flow. It can be helpful for blood pressure.

However, limited studies of arginine supplements have shown little to no effect on increasing blood flow or blood pressure. Doses of up to 9 grams per day appear to be safe, but some people report side effects such as nausea and diarrhea, according to the National Institutes of Health Office of Dietary Supplements.

As you can see, even supplements can have side effects. We’re just not so clear on what they are, as research on many of these products is often limited. In addition, products marketed as dietary supplements do not have to go through strict safety measures like drugs do. That is why you should always have them performed by your health care provider, who knows your individual health needs.

And yes, I have a recommendation for an over the counter product that helps lower blood pressure without the usual side effects. It’s called the DASH diet – a well-researched diet high in potassium, calcium, and magnesium. The right combination of these nutrients in food has been shown to lower blood pressure. Check it out at www.nhlbi.nih.gov/health-topics/dash-eating-plan.