High blood pressure is the number one modifiable risk factor for heart disease, heart attack, and stroke. It occurs when the force of blood pushing against the walls of your arteries is too great, causing damage to the epithelial cells there, which can lead to a condition called atherosclerosis, resulting in fat buildup that forms plaques in the blood vessels.

But despite the fact that there are effective medications for high blood pressure, the majority of people with the condition (some estimates are as high as 75 percent) have difficulty controlling it, even with multiple drugs.

Nitric oxide regulates vascular (blood vessel) tone, therefore controlling blood pressure. In fact, the loss of nitric oxide production — called “endothelial dysfunction” — is the earliest danger sign for developing high blood pressure.

This has led to tremendous interest in nitric oxide for preventing high blood pressure. It’s a good reason to consider taking nitric oxide not as a substitute for high blood pressure medication, but in addition to it if your blood pressure is high.

If your blood pressure is normal, nitric oxide can help keep it that way. A review of 22 studies published in 2021 by the journal Nitric Oxide found that taking the supplement significantly reduced blood pressure, especially in people 65 or over who were overweight or had mild hypertension (prehypertension).

In another small study, researchers from Florida State University in Tallahassee gave four men and five women with high blood pressure an extract containing L-arginine daily for six weeks. All demonstrated improved arterial function, which consequently lowered their blood pressure.

Some research also finds that the compound can benefit people who have pulmonary hypertension, a form of high blood pressure that affects the vessels in the lungs.

Once again, L-arginine is not a substitute for blood pressure medication. And if your blood pressure is well controlled by a medication, check with your doctor before using L-arginine to make sure it won’t fall too low with the supplement.