Just because a weight-loss pill advertises that it is “natural” doesn’t necessarily mean that it’s safe, especially if you have high blood pressure. Because these weight-loss pills aren’t regulated by the U.S. Food and Drug Administration, they can be marketed with little evidence to buttress their health claims and little research into their side effects.
Consult Your Doctor
If you have high blood pressure, consult your doctor before taking any weight-loss pills. Don't speak in generalities: Because they differ widely, bring in the actual weight-loss supplement so that she can advise you if it’s safe to take it or if the pill contains ingredients that could raise your blood pressure or interact with any medication you are taking.
Orlistat is marketed as Xenical (prescription) and Alli (over the counter). It controls the amount of fat absorbed into your body through the digestive tract, helping reduce your caloric intake. While it is considered safe to take with regard to blood pressure, it can cause digestive issues in some patients.
Water pills—also known as diuretics—can help prevent bloating and provide short-term weight loss, as they cause the body to shed excess fluid. Some physicians prescribe them as an initial treatment for high blood pressure, as they don’t cause the side effects that many blood-pressure medications can cause.
A study published in the December 2002 issue of "The Journal of the American Medical Association" showed that diuretics were better at lowering the systolic blood pressure reading than many newer medications. It should be noted, however, that their extended use can be taxing on the kidneys, so consult your doctor before using them over the counter.
General Weight-Loss Advice
If you are overweight, shedding excess pounds can help lower your blood pressure. According to the Mayo Clinic, losing even 5 to 10 percent of your body weight over a year can result in significant improvements to your blood pressure and triglyceride and insulin levels. Although you may see short-term results when using diet pills, the weight loss will be temporary if you don't change your eating and exercise habits and burn more calories each day than you consume.
Why Most Pills Are Contra-Indicated
Be aware that many weight-loss pills work by accelerating your metabolism so that your body burns more calories. However, this creates an elevated heart rate, which can in turn increase your blood pressure.