Hepatitis C and Dietary Supplements

About Hepatitis C

Hepatitis C is a liver disease caused by a virus. It’s usually chronic (long-lasting), but most people don’t have any symptoms until the virus causes liver damage, which can take 10 or more years to happen. Without medical treatment, chronic hepatitis C can eventually cause liver cancer or liver failure. Hepatitis C is usually treated with a combination of medicines.

Hepatitis C virus is contagious. People usually get the virus through contact with blood from a person who’s already infected or, less commonly, through having sex with an infected person. The infection usually becomes chronic.

An estimated 2.7 to 3.9 million people in the United States have chronic hepatitis C.

About Dietary Supplements for Hepatitis C

Several dietary supplements have been studied for hepatitis C, and many people with hepatitis C have tried dietary supplements. The most commonly used supplement for hepatitis C is silymarin (an extract from milk thistle).

What the Science Says About Dietary Supplements for Hepatitis C

Silymarin (Milk Thistle)

• Milk thistle (scientific name Silybum marianum) is a plant from the aster family. Silymarin is an extract from milk thistle.
  • A 2014 evaluation of five studies of silymarin in people with hepatitis C, involving a total of 389 participants, did not show silymarin to be beneficial. The supplement did not improve liver function or decrease levels of the hepatitis C virus.
  • One of these studies, cofunded by the National Center for Complementary and Integrative Health (NCCIH) and NIDDK, showed that higher-than-usual doses of silymarin, given for 24 weeks, were no better than a placebo (an inactive substance) in improving a measure of liver function in people who had not responded to drug treatment for chronic hepatitis C. The study, completed in 2012, had 154 participants. Those receiving silymarin also showed no significant differences from participants receiving the placebo in hepatitis C virus levels or quality of life.
  • Side effects have been uncommon in studies of silymarin in people with hepatitis C. When side effects occurred, they were usually mild digestive problems, like bloating, indigestion, nausea, or diarrhea.

Probiotics

• Probiotics are live microorganisms that are intended to have a health benefit. Research hasn’t produced any clear evidence that probiotics are helpful in people with hepatitis C. In healthy people, probiotics usually have only minor side effects, if any. However, in people with underlying health problems (for example, weakened immune systems), serious side effects such as infections have occasionally been reported.

Zinc

• Preliminary studies, most of which were conducted outside the United States, have examined the use of zinc for hepatitis C. Zinc supplements might help to correct zinc deficiencies associated with hepatitis C, reduce some symptoms, or improve patients’ response to treatment, but the evidence for these possible benefits is limited. Zinc is generally considered to be safe when used appropriately, but it can be toxic if taken in excessive amounts.

Licorice Root and Glycyrrhizin

• Dietary supplements containing glycyrrhizin—a compound found in licorice root—have been tested in a few studies in people with hepatitis C, but there’s currently not enough evidence to determine if they’re helpful. Glycyrrhizin or licorice can be dangerous in people with a history of hypertension (high blood pressure), kidney failure, diabetes, or cardiovascular diseases.

Colloidal Silver

• Colloidal silver has been suggested as a treatment for hepatitis C, but there’s currently no research to support its use for this or any other purpose. Colloidal silver is known to cause serious side effects, including a permanent bluish discoloration of the skin called argyria.

Other Dietary Supplements

• Preliminary studies have examined the potential of the following products for treating chronic hepatitis C: TJ-108 (a mixture of herbs used in Japanese Kampo medicine), oxymatrine (an extract from the sophora root), chlorella (a type of algae), black cumin(Nigella sativa), S-adenosyl-L-methionine (SAMe), and thymus extract (from cattle). The limited research on these products hasn’t produced convincing evidence that they’re helpful for hepatitis C.
• A few preliminary studies have looked at the effects of combining supplements such as lactoferrin, SAMe, or zinc with conventional drug therapy for hepatitis C. The evidence isn’t sufficient to draw clear conclusions about benefit or safety.
• Preliminary research has looked at substances that might reduce the risk of liver cancer in people with hepatitis C, including dietary supplements such as carotenoids and vitamin K, but the evidence is too limited for conclusions to be reached.

Key References

• Dhiman RK, Chawla YK. Herbal medicines for liver diseases. Digestive Diseases and Sciences. 2005;50(10):1807-1812.
• Fried MW, Navarro VJ, Afdhal N, et al. Effect of silymarin (milk thistle) on liver disease in patients with chronic hepatitis C unsuccessfully treated with interferon therapy: a randomized controlled trial. JAMA. 2012;308(3):274-282.
• Grüngreiff K, Reinhold D. Zinc: a complementary factor in the treatment of chronic hepatitis C? Molecular Medicine Reports. 2010;3(3):371-375.
• Kaito M, Iwasa M, Fujita N, et al. Effect of lactoferrin in patients with chronic hepatitis C: combination therapy with interferon and ribavirin. Journal of Gastroenterology and Hepatology. 2007;22(11):1894-1897.
• Matsumura H, Nirei K, Nakamura H, et al. Zinc supplementation therapy improves the outcome of patients with chronic hepatitis C. Journal of Clinical Biochemistry and Nutrition. 2012;51(3):178-184.
• Prasad AS. Zinc: role in immunity, oxidative stress and chronic inflammation. Current Opinion in Clinical Nutrition and Metabolic Care. 2009;12(6):646-652.
• Yang Z, Zhuang L, Lu Y, et al. Effects and tolerance of silymarin (milk thistle) in chronic hepatitis C virus infection patients: a meta-analysis of randomized controlled trials. BioMed Research International. 2014;2014:941085.

NCCIH Pub No.: D422

Last Updated: May 2018