Echinacea

Background

• Echinacea species are perennials that are closely related to sunflowers, daisies, and ragweed. Though widely cultivated today, echinacea species are native to areas east of the Rocky Mountains in the United States. 
• The E. purpurea species of echinacea was originally discovered by Native Americans in North America, who used the plant medicinally for respiratory tract infections, tooth pain, and snakebite.
• Today, echinacea products are primarily promoted as a dietary supplement for the common cold and other respiratory tract infections, based on the idea that certain species of echinacea may stimulate the immune system.
• Some echinacea products may be promoted for topical use (application to the skin) for various skin problems, like eczema.

How Much Do We Know?

• Many studies have been done in people on echinacea for the common cold and other respiratory tract infections. Much less research has been done on the use of echinacea for other health purposes.

What Have We Learned?

• Taking echinacea may slightly reduce your chances of catching a cold. It’s still unclear whether echinacea can shorten the length of a cold. More research is needed to confirm these findings.
• One recent study found that echinacea might reduce the chance of respiratory tract infection and associated complications in children, but overall, there isn’t enough evidence to support a clear connection. Before giving a child an echinacea product, talk with the child’s health care provider. 
• It’s unclear whether echinacea is helpful for other health conditions, including eczema.
• Recent National Center for Complementary and Integrative Health (NCCIH)-sponsored research suggests that the activity of echinacea extracts is influenced by soil conditions that affect the plant’s bacterial community.

What Do We Know About Safety?

• It’s likely safe for most adults to consume products with extracts of E. purpurea, and some mixtures of E. purpurea and E. angustifolia, for short periods of time. However, some people have allergic reactions to echinacea, which may be severe. The most common side effects of echinacea are digestive tract symptoms, such as abdominal pain, nausea, or stomach pain.
• It’s possibly safe for children to consume E. purpurea extract for short periods of time. However, some children participating in a clinical trial of echinacea developed rashes, which may have been caused by an allergic reaction. There is concern that allergic reactions could be severe in some children. Before giving echinacea to a child, talk with the child’s health care provider.
• There is conflicting evidence about whether echinacea interacts with some drugs metabolized by the liver, and there are theoretical reasons to suspect that echinacea might interact with immunosuppressants or caffeine. If you take any type of medicine, talk to your health care provider before using echinacea or other herbal products; some herbs and medicines interact in harmful ways.
• Some studies of the use of solid or liquid extracts of E. purpura and E. angustifolia suggest it is possibly safe for up to 7 days during the first trimester of pregnancy. If you’re considering using echinacea while pregnant, consult your health care provider. Little is known about whether it’s safe to use echinacea while breastfeeding.

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