As of 2015, there are no medically supported studies indicating herbs raise blood sugar levels; however, alternative medical therapies can be either effective or harmful, according to WebMD. Herbal supplements as treatment for diabetes are considered complementary and alternative medicine, used to support or replace conventional medical treatment. Patients should consult their health care providers before using alternative methods for treating diabetes.
Many herbal supplements make unsupported claims about their effectiveness, and patients should look for packaging that identifies the herb's common and scientific name, side effects, expiration date, dosage and manufacturer's name and address, advises WebMD. In some cases, herbal supplements have been recalled and banned by the FDA due to harmful side effects, including high blood pressure, urinary retention, insomnia and glaucoma. Ephedrine, an herbal weight-loss supplement, was banned after it became associated with several instances of stroke.
Herbal supplements that are currently undergoing testing for treating diabetes include American ginseng, which has demonstrated in clinical studies to lower blood sugar levels during fasting and post-meal periods, states WebMD. However, larger long-term studies are necessary before making recommendations regarding medical use. There are several varieties of ginseng on the market, but only American ginseng has been tested for treating diabetes. Other varieties have a range of blood sugar-lowering properties that have not yet been determined.
Other supplements associated with lowering blood sugar include magnesium, chromium and vanadium, notes WebMD. Diabetics with low levels of magnesium may experience more complications, including less control of blood sugar and insulin secretion. Vanadium has been shown to normalize blood sugar in animal studies, but safe dosages and side effects in humans are still undetermined.