What to Know About Herbs and Surgery

By Iliades, Chris 
March 20, 2017

What to Know About Herbs and Surgery

Millions of Americans use an herbal supplement for health benefits. It could be echinacea to avoid a cold or gingko to improve memory. On the surface, using these products sounds like a good idea. They are considered “natural” and are sold in pharmacies and health stores. You might think that they must be safe.

Unfortunately, natural doesn’t necessarily mean safe. The FDA doesn’t regulate herbal supplements the same way it does prescription and over-the-counter (OTC) medicines. The standards of safety are not the same. That could be a problem for you, especially if you need to have surgery.

The American Society of Anesthesiologists, among other health organizations, recommends that all herbal supplements be stopped 2 to 3 weeks before surgery. That's because these herbs can have side effects that could make surgery more dangerous for you.

Herbs as medicine

The use of plants as medicines goes back to ancient times. The Egyptians used aloe vera to prolong life. The Bushmen of the Kalahari in Africa have used the flowering cactus hoodia for centuries to ward off hunger. In India and China herbal medicines are important parts of medical practice.

Many of the medicines we depend on every day, including digitalis, aspirin, morphine, and even some important cancer medicines, are based on plants. The problem is that when you take an herbal supplement that has not been tested or regulated for safety by the FDA, you don't really know what you are getting.

Herbs can have unexpected side effects. And, for many herbal supplements, all the active ingredients may not be known. Since most of these products have not been studied in large, controlled research trials, their safety, side effects, and their effectiveness aren’t reliably known. And, since the manufacturing process isn't well-regulated, some supplements may contain ingredients that are not on the label. 

The problem with herbs and surgery

Taking herbs in the weeks before surgery could cause a negative reaction with anesthesia medicines or prolonged bleeding during and after surgery. This is especially dangerous because many people taking herbal supplements don't tell their surgeon or anesthesiologist about them.

An article published in the Journal of the American Medical Association listed these 8 common herbal supplements in particular that could be a problem if you need to have surgery:

  • Echinacea. This herb comes from the purple cornflower and is taken for colds, infections, arthritis, and ulcers. If you have liver disease and you have anesthesia while taking echinacea, you could end up with liver damage.

  • Ephedra. Also called ma-huang, this herb from the plant ephedra sinica is used for asthma and to suppress appetite. When combined with some anesthesia medicines, it can cause high blood pressure and abnormal heart rhythms. The FDA banned it in 2003 after being linked to several deaths.

  • Garlic. Garlic supplements are used to lower blood pressure and cholesterol. Garlic can increase the effects of medicines used to control blood sugar, blood thinners, and some OTC pain relievers, and it can increase bleeding during or after surgery.

  • Ginkgo. Ginkgo biloba is used to improve memory. But it may cause prolonged bleeding during or after surgery and make the sedation effects of anesthesia last longer.

  • Ginseng. Ginseng is commonly used for an energy boost or to lower blood sugar levels. During surgery, ginseng may cause high blood pressure and a rapid heart rate.

  • Kava. Kava comes from the piper methysticum plant and is used for muscle relaxation and to calm the nerves. It may be dangerous for people having surgery because of its interactions with other medicines. It may also cause liver damage.

  • St. John's wort. Also known as goatweed, this herb is taken to relieve depression and anxiety. During a surgical procedure, St. John's wort may interfere with some anesthesia medicines and make it harder for you recover from the effects of anesthesia.

  • Valerian. This herb from the plant valeriana officinalis is used to relieve anxiety. It may increase the effects of anesthesia and make it more difficult to wake up after surgery. It may also cause irregular heart rhythms.

Other herbal supplements that may increase bleeding include feverfew, ginger, and saw palmetto. Herbal supplements that could interfere with your blood pressure during surgery include goldenseed, licorice, and milk thistle.

Remember that herbal supplements are not FDA-approved medicines. They may have many benefits, but they don't have the same reliability and safety as prescription medicines and OTC medicines.

The best advice is to talk with your healthcare provider about all OTC medicines and herbal supplements you’re taking. If you have any surgery scheduled in your future, have this discussion as soon as possible. Also, plan to stop these herbal supplements in the weeks before your operation. 


March 20, 2017


Herbal Medicines and Perioperative Care. Ang-Lee M. Journal of the American Medical Association. 2001;286(2):208-16.

Reviewed By:  

Demuro, Jonas, MD,Taylor, Wanda, RN, Ph.D.