Everything we eat, drink, breathe, smoke, inject and apply to the skin passes through the liver. The liver processes everything it can, and tries to eliminate or metabolize potentially harmful substances, such as drugs or alcohol. If a substance is toxic, or if there is too much of it, the liver can become overburdened. This is particularly true about alcohol and drugs, whether prescription, nonprescription, or illicit. Smoking cigarettes or marijuana may also harm the liver.



To protect your liver, try to avoid all alcohol use if you have liver disease. Research shows that alcohol increases hepatitis replication, promotes damage to the liver and increases the likelihood of developing cirrhosis. Even moderate amounts of alcohol may increase your risk of fibrosis. Heavy alcohol use increases the risk of hepatocellular carcinoma, a type of liver cancer.


If you can’t or don’t want to stop drinking, try to limit your alcohol intake. The U.S. Department of Agriculture and U.S. Department of Health and Human Services’ Dietary Guidelines for Americans 2010 for moderate alcohol consumption is one drink per day for women and two drinks per day for men. The size of standard drinks depends on what you are drinking:

  • 12 ounces of regular beer, which is usually about 5 percent alcohol
  • 5 ounces of wine, which is typically about 12 percent alcohol
  • 5 ounces of distilled spirits, which is about 40 percent alcohol 

Binge drinking is especially harmful to the liver, so not drinking during the week so you can drink more on the weekends is risky. If stopping or reducing alcohol is a goal for you but you find it difficult to do, ask your doctor for help.



In addition to harming the liver, people who inject drugs are at high risk for acquiring and spreading viruses, such as hepatitis. Anything used in the process of preparing and injecting drugs may be a vehicle for spreading hepatitis, including syringes, cookers, cotton filters, preparation water, the surface on which the drug is prepared, and the drug itself. Disinfecting needles and syringes with household bleach may prevent hepatitis transmission.


Inhaling drugs may also transmit hepatitis via tiny droplets of blood passed on straws. The nasal passages break easily, particularly when they are dry. There is also a risk of passing hepatitis through mouth sores, chapped lips or bleeding gums when sharing items like crack pipes.


To reduce risk of contracting or transmitting hepatitis and to protect the liver, consider stopping illicit drug use. Treatment programs can help with this. If you do continue to use, some ways that may reduce your risk are:

  • Don’t share needles, syringes, water or drug preparation equipment.
  • Only use needles, syringes and other equipment that was new and obtained from a reliable source, such as a pharmacy or needle-exchange program.
  • Be sure the surface you are preparing drugs on is clean and has not been exposed to hepatitis.
  • Use clean water from a reliable source (bottled or fresh tap water) and from a container that has not held previously contaminated water.
  • Use a new cooker and filter to prepare drugs.
  • Safely dispose of syringes so that others are not harmed. 


Smokers with hepatitis have a higher rate of liver cancer than nonsmokers. Recent research using mice found that nicotine aerosol (vaping) demonstrated profound adverse effects on the liver.


Switching to vaping may be less harmful than continuing to smoke, but a growing body of evidence shows that using aerosolized nicotine is hazardous too. Quitting nicotine is always a good idea, but stopping can be hard. If you are interested in quitting nicotine, talk to your health care provider. 


Last Reviewed: June 29, 2023