What’s the Bottom Line?

What do we know about the effectiveness of dietary supplements for hepatitis C?

• No dietary supplement has been shown to be effective for hepatitis C.
• Several studies of silymarin (milk thistle) dietary supplements in people with hepatitis C did not find beneficial effects.

What do we know about the safety of dietary supplements for hepatitis C?

• Colloidal silver, which has been claimed to be helpful for hepatitis C, is not safe; it can cause irreversible side effects.
• In studies of silymarin (milk thistle) supplements for hepatitis C, side effects were uncommon and usually mild.
• Data on the safety of other supplements is limited. However, some can have side effects or may interact in harmful ways with medications.

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.

NCCIH-Funded Research

NCCIH-supported research on hepatitis C includes projects studying:

• Potential drugs for treating hepatitis C derived from rare and endangered plants
• The interactions of silymarin with liver cells.

More To Consider

• Don’t use any complementary health approach to replace conventional treatment for hepatitis C or as a reason to postpone seeing your health care provider about any medical problem.
• Be aware that dietary supplements may have side effects or interact with conventional medical treatments.
• If you’re pregnant or nursing a child, or if you’re considering giving a child a dietary supplement, it’s especially important to consult your (or the child’s) health care provider. Many supplements have not been tested in pregnant women, nursing mothers, or children.
• Tell all your health care providers about any complementary or integrative health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.

Current research suggests that milk thistle is no better than placebo as a treatment for hepatitis C.

What Does the Research Show?

• A 2014 meta-analysis of five randomized controlled trials found that the effects of silymarin on alanine aminotransferase (ALT) levels of patients with hepatitis C were similar to those of placebo; however, no beneficial effects were found for silymarin. Improvements in the quality of life of silymarin and placebo recipients were relatively identical.
• A 2012 controlled trial showed that two higher-than-usual doses of silymarin were no better than placebo in reducing alanine aminotransferase (ALT) levels in patients with chronic hepatitis C. Decreases in serum ALT levels are correlated with improvement in hepatic necroinflammatory activity after interferon therapy for hepatitis C.
• Findings from the 2008 HALT-C study suggest that silymarin use by hepatitis C patients was associated with fewer and milder symptoms of liver disease and somewhat better quality of life, but there was no beneficial effect found on serum ALT or hepatitis C virus RNA levels. It is important to note that the finding of improved quality of life in patients taking silymarin was not confirmed in the more rigorous 2012 study described above.
• A 2009 Cochrane systematic review assessed the beneficial and harmful effects of milk thistle in patients with alcoholic liver disease and/or hepatitis B or C liver diseases and found that there is not enough high-quality evidence to support the use of this intervention.

Safety

• Available evidence from clinical trials in people with liver diseases suggests that milk thistle is generally well-tolerated.
• Side effects can include a laxative effect, nausea, diarrhea, abdominal bloating and pain, and occasional allergic reactions.

Only a few studies have examined the effects of probiotics on hepatitis C, and of those studies, there isn’t any clear evidence that probiotics are helpful in people with hepatitis C.

What Does the Research Show?

• A 2014 randomized controlled trial involving 53 patients with chronic liver disease found that short-term probiotic administration is effective in alleviating small intestinal bacterial overgrowth and clinical symptoms, but ineffective in improving intestinal permeability and liver function.

Safety

• Most people can use probiotics without experiencing any side effects—or with only mild gastrointestinal side effects—but there have been some case reports of serious adverse effects in people with underlying serious health conditions.

Preliminary studies, most of which were conducted outside the United States, have found that 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.

What Does the Research Show?

• A 2015 multicenter randomized controlled trial in 53 patients with hepatitis C found that branched-chain amino acids (BCAA) and zinc-enriched supplements reduced the serum α‑fetoprot (AFP) levels in patients who had elevated serum AFP levels at baseline. The authors of the study concluded that BCAA and zinc-enriched supplementation may prolong the survival of patients with hepatitis C by improving amino acid imbalance and zinc deficiency, and by partly down regulating AFP.
• A 2012 study evaluating the effects of vitamins E, C, and zinc on oxidative stress in patients with hepatitis C found that the antioxidant supplementation had a protective effect on participants, attenuating oxidative stress related to the disease.

Safety

• Zinc is generally considered to be safe when used appropriately, but it can be toxic if taken in excessive amounts.

There is currently insufficient evidence to determine if glycyrrhizin is efficacious for hepatitis C.

What Does the Research Show?

• A 2012 randomized controlled trial in 379 patients with chronic hepatitis C who failed to respond to previous interferon-based therapies found that glycyrrhizin exhibited a significantly higher ALT reduction compared to placebo after 12 weeks of therapy and an improvement of necro-inflammation and fibrosis after 52 weeks of treatment.

Safety

• In large amounts, glycyrrhizin or licorice can be dangerous in people with a history of hypertension, renal failure, or cardiovascular diseases.

Hepatitis C is a liver disease caused by a virus. It is usually chronic (long-lasting), but most people do not 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. Conventional medical treatments are available for chronic hepatitis C. Some people with hepatitis C also try complementary health approaches, especially dietary supplements.

If you are considering any dietary supplement for hepatitis C, here are some things you should know.

1. No dietary supplement has been shown to be effective for hepatitis C or its complications.

2. The results of research supported by the National Institutes of Health have shown that silymarin, the active extract of milk thistle and the most popular complementary health product taken by people with liver disease, was no more effective than placebo in people with hepatitis C.

3. Research on other dietary supplements for hepatitis C, such as zinc, licorice root (or its extract glycyrrhizin), SAMe, and lactoferrin, is in its early stages, and no firm conclusions can be reached about the potential effectiveness of these supplements.

4. Colloidal silver is sometimes promoted for treating hepatitis C, but is not safe. Colloidal silver can cause irreversible side effects, including a permanent bluish discoloration of the skin.

5. Check with your health care provider before using any dietary supplement to make sure that it is safe for you and compatible with any medical treatment that you are receiving for hepatitis C or any other health problem.