Herbal Supplements and Alcohol Interactions

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on June 26, 2024.

Many people believe "natural products" are safe to use when drinking alcohol, but this is not always the case. For example, supplements like St. John's Wort, melatonin or valerian may interact with alcohol and lead to drowsiness, confusion, dizziness, impaired driving or other side effects.

Well-designed clinical trials evaluating interactions between dietary supplements and alcohol use are often lacking, even though alcohol, herbal products, vitamins and dietary supplements are widely used by the public.

In many cases, you'll need to check with your doctor or pharmacist to determine if there is a possible risk when combining an herbal supplement with alcohol use.

Learn More: Check Herbal Supplements for Drug Interactions

Drowsiness, Central Nervous System (CNS) Depression

Use caution if combining alcohol with any over-the-counter herbal or dietary supplement that causes drowsiness. Review the label on the bottle and speak with your pharmacist or doctor if you plan on mixing an herbal dietary supplement and alcohol.

Do not drive, operate machinery or perform other hazardous activities if you have been drinking or if your supplement makes you feel tired.

These herbal drugs have been known to lead to drowsiness in some patients, which may be increased when combined with alcohol:

Panax ginseng (ginseng) has been reported to reduce the blood concentrations of alcohol (ethanol) in one case report.

Liver Damage

Some herbal products may lead to liver damage as well. Chronic alcohol abuse and alcoholism can lead to liver disease such as cirrhosis. The effects may be additive when combined with herbs or other dietary supplements that can also harm the liver.

Examples of herbal products that may cause liver toxicity include:

The fat soluble vitamins A, D, E and K are usually consumed from your diet and play an important role in your health. If you take these vitamins in the form of supplements, it is important not to exceed recommended doses. High doses of these vitamins may lead to liver damage. Alcohol combined with high doses of fat-soluble vitamins may theoretically lead to, or worsen, liver damage.

Alcohol can also inhibit the proper absorption of other vitamins like vitamin B1 (thiamin), vitamin B12, folic acid, and zinc.

Alcohol itself holds little to no nutritional value, can cause dehydration and is a source of empty calories that may lead to weight gain.

Low Blood Pressure

Rauwolfia serpentina and alcohol may have additive effects in lowering your blood pressure (medically called hypotension). Side effects can include headache, dizziness, lightheadedness, fainting, or changes in heart rate. These side effects are most likely to be seen when you start treatment, when your dose is increased, or if treatment is restarted after you have stopped therapy.

Rauwolfia serpentina

*Note: This is not a complete list of interactions; always check with your pharmacist or doctor for possible drug-alcohol interactions. Tell your healthcare providers about all the other medications you use, including prescription, over-the-counter (OTC) drugs, vitamins, dietary supplements and herbal products.

Bottom Line

Drug interactions between alcohol use and herbal or dietary supplements like St. John's Wort, black cohosh or fat-soluble vitamins are possible and can lead to varied side effects.
Enhanced drowsiness or confusion, liver toxicity or effects on blood pressure are just some of the side effects that may occur when herbal supplements are combined with alcohol.
Certain people may be at greater risk when alcohol is mixed with supplements or vitamins. The older population tend to break down alcohol more slowly in their body, women (who have a lower percent body water and concentrate alcohol) and those who take multiple medications are all at greater risk for serious drug interactions.

Types of Drug Interactions With Alcohol

Sources

Weathermon R, Crabb DW. Alcohol and medication interactions. Alcohol Res Health. 1999;23(1):40–54. Accessed June 18, 2024 at PMID: 10890797.
Miller L. Herbal Medicinals: Selected Clinical Considerations Focusing on Known or Potential Drug-Herb Interactions. Arch Intern Med. 1998;158(20):2200-2211. June 18, 2024 at doi:10.1001/archinte.158.20.2200
Ekors M. The growing use of herbal medicines: issues relating to adverse reactions and challenges in monitoring safety. Front Pharmacol. 2013; 4: 177. Accessed June 18, 2024 at doi: 10.3389/fphar.2013.00177.
Lee FC, Ko JH, Park JK, et al. Effects of Panax ginseng on blood alcohol clearance in man. Clin Exp Pharmacol Physiol 1987; 14(6): 543–6
Jamieson DD, Duffield PH. Positive interaction of ethanol and kava resin in mice. Clin Exp Pharmacol Physiol 1990; 17: 509–14
How alcohol affects you. UC San Diego. Accessed June 12, 2024 at https://studenthealth.ucsd.edu/resources/health-topics/alcohol-drugs/nutrition-endurance.html

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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