Fish oil, garlic, coenzyme Q10, and vitamin C may lower blood pressure a small amount. They need further study to be sure this effect is true. No studies have been done to prove they lower the risk of blood pressure complications like heart disease or stroke.  Most experts and doctors do not recommend supplements and herbal remedies to lower blood pressure. 

Dietary supplements and herbal remedies aren’t regulated the way other medicines are. That means they can be sold without proven effectiveness. It also means they are not tested for safety. In fact, some may not actually contain what the label claims. It is best to talk to your doctor before you take herbs or supplements. They don’t always mix well with other medicines. Some of them can even be harmful to your health.

Dietary Supplements with Some Evidence 

Fish Oil 

Fish oil is found in oily fish like salmon and herring. It contains omega-3 fatty acids. They may have heart-healthy effects. You can get omega-3 from eating fish or by taking fish oil pills. Some studies show taking fish oil lowers blood pressure slightly. Side effects of fish oil include stomach upset and burping. In large doses, fish oil may cause bleeding. 

Garlic 

Garlic is an edible bulb. It is sold fresh, in powder or oil form, and in a pill. Some studies show it may lower blood pressure slightly. But more study is needed to prove this. It appears to be safe for most people. Side effects include bleeding, upset stomach, body odor, and bad breath. It may make some other medicines less effective, too. 

Coenzyme Q10 

Coenzyme Q10 is an antioxidant some people take as a supplement. It occurs naturally in the body, but levels are lower in some people. Antioxidants can protect the body’s cells from damage. Some studies show coenzyme Q10 can lower blood pressure. Others say the effect on blood pressure is small at best. As far as is known, there are few harmful effects. It may cause upset stomach or headaches. People taking other medicines such as blood thinners, insulin, or cancer treatments should use caution when taking coenzyme Q10. 

Vitamin C 

Vitamin C occurs in many foods such as green vegetables and citrus fruits. It is also sold as a supplement. It is an antioxidant. This means it may prevent cell damage in the body. It may help to lower blood pressure slightly in people already taking medicine for blood pressure. It may be more helpful to older people than younger people, but more study is needed. 

Dietary Supplements without Strong Evidence 

Many other herbs and supplements claim to lower blood pressure. But there is just not enough scientific evidence to prove these claims. In fact, they could cause more harm than good. You should be cautious if you choose to use them. 

The Bottom Line 

Talk to your doctor before taking an herbal remedy or supplement. Some may help your blood pressure slightly. Most will not lower your blood pressure. Some may actually interfere with other medicine or treatments. If you do use an herbal remedy or supplement, do so with caution.