Goldenseal

Background

• Goldenseal is a plant native to the northeastern United States and southeastern Canada. It has a bright yellow rhizome (underground stem). Wild goldenseal has been overharvested and is available in limited amounts. The plant is grown commercially but is expensive to cultivate.
• Historically, Native Americans used goldenseal to treat a variety of conditions, such as digestive disorders, wounds, skin and eye conditions, and cancer.
• Currently, goldenseal is promoted as a dietary supplement for the common cold and other upper respiratory tract infections, hay fever, diarrhea, constipation, and other conditions.

How Much Do We Know?

• There is not enough evidence to determine whether goldenseal is useful for any health conditions. More research would be needed before any conclusions can be reached.

What Have We Learned?

• No rigorous studies have been done to evaluate the effects of goldenseal on health conditions in people.
• Berberine, a substance found in goldenseal, has been studied for its effects on blood sugar, blood cholesterol levels, body weight, and other health-related outcomes. However, when people take goldenseal orally (by mouth), very little berberine may be absorbed by the body, so study results on berberine may not apply to goldenseal.

What Do We Know About Safety?

• In small research studies, goldenseal has been administered at doses of about 3 g per day for short periods of time without serious harmful effects. The safety of taking goldenseal for longer periods is uncertain.
• Some commercial goldenseal products have been found to contain other herbs or ingredients not listed on the label in addition to or instead of goldenseal.
• Goldenseal may change the way your body processes many medications. For example, a study funded by the National Center for Complementary and Integrative Health (NCCIH) found that levels of metformin—the most commonly prescribed diabetes medicine—decreased about 25 percent in healthy adults who were given goldenseal extract plus metformin. This drop was enough to potentially hinder glucose control in people with type 2 diabetes taking metformin. If you take any type of medicine, talk with your health care provider before using goldenseal or other herbal products; some herbs and medicines interact in harmful ways.
• Women who are pregnant or breastfeeding should not use goldenseal, and it should not be given to infants. The berberine constituent of goldenseal can be harmful to newborns.

Keep in Mind

• Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.
• Federal Regulation of Herbal Products
  • Depending on what’s in them, how they’re intended to be used, and how they’re administered (orally or topically), herbal products are regulated in a variety of ways. Many herbal products intended for oral use are marketed as dietary supplements. The rules for making and distributing dietary supplements are less strict than those for drugs.
  • Unlike drugs, dietary supplements are not approved by the U.S. Food and Drug Administration (FDA) before they are sold to the public. When public health concerns arise about the safety of a dietary supplement or an ingredient including an herb, the FDA can take action to protect the public. Manufacturers and distributors of supplements are responsible for evaluating the safety and labeling of their products before marketing to ensure that they meet all regulatory requirements.

For More Information

• Using Dietary Supplements Wisely
• Know the Science: How Medications and Supplements Can Interact
• Know the Science: How To Make Sense of a Scientific Journal Article

Key References