Valerian : Safety

by MedlinePlus

(Page 2 of 2)

Allergies

People with allergies to plants in the Valerianaceae family may be allergic to valerian.

Side Effects and Warnings

Studies report that valerian is generally well tolerated for up to 4 to 6 weeks in recommended doses, and side effects may occur no more often than with placebo (sugar pill). Valerian has occasionally been reported to cause headache, excitability, stomach upset, uneasiness, dizziness, unsteadiness (ataxia) and low body temperature (hypothermia). Chronic use (longer than 2-4 months) may result in insomnia. Slight reductions in concentration or complicated thinking may occur for a few hours after taking valerian. Use caution if you are driving or operating heavy machinery. Some research suggests that valerian may not cause sedation.

A drug "hangover" effect has been reported in people taking high doses of valerian extracts. "Valerian withdrawal" may occur if you stop using valerian suddenly after chronic high-dose use, including confusion (delirium) and rapid heartbeat. These symptoms may improve with the use of benzodiazepines such as lorazepam (Ativan®). Although unknown, valerian may have similar brain activity as benzodiazepines (which are commonly used to treat anxiety and insomnia), through effects on the brain chemical gamma-amino-butyric-acid (GABA).

Valerian has been on the U.S. Food and Drug Administration's GRAS (generally regarded as safe) list, and no deaths due to overdose have been reported. Symptoms with overdose or chronic use may include low blood pressure, slow or abnormal heart rhythm, chest tightness, lightheadedness, constipation, excitability, blurred vision, tremor, headache, hypersensitivity (allergic) reactions, insomnia, and stomach upset.

Liver toxicity has been associated with some multi-herb preparations that include valerian. However, the contribution of valerian itself is not clear due to the potential liver toxicity of other included ingredients, or the possibility of contamination with unlisted herbs.

Pregnancy and Breastfeeding

Because there is limited human safety data, valerian use during pregnancy and breastfeeding is not recommended. There are theoretical concerns over the adverse effects of chemical components that are toxic in laboratory studies.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

Based on animal and human studies, valerian may increase the amount of drowsiness caused by some drugs, although this is an area of controversy. Examples include benzodiazepines such as lorazepam (Ativan®) or diazepam (Valium®), barbiturates such as phenobarbital, narcotics such as codeine, some antidepressants, and alcohol. Caution is advised while driving or operating machinery. In one human study, a combination of valerian and 20 milligrams of the beta-blocker drug propranolol (Inderal®) reduced concentration levels more than valerian alone. A brief episode of confusion was reported in one patient using valerian with loperamide (Imodium®) and St. John's wort ( Hypericum perforatum L.).

An episode of agitation, anxiety and self-injury was reported in a patient after taking valerian with fluoxetine (Prozac®) for a mood disorder (the person was also drinking alcohol). In theory, valerian may interact with anti-seizure medications, although there is no human data of such an interaction. Valerian tinctures may contain high alcohol content (15-90%), and theoretically may cause vomiting if taken with metronidazole (Flagyl®) or disulfiram (Antabuse®). Valerian may interact with certain drugs metabolized by the liver.

Interactions with Herbs and Dietary Supplements

Based on theoretical concerns, valerian may increase the amount of drowsiness caused by some herbs or supplements. Examples include: calamus, calendula, California poppy, capsicum, catnip, celery, couch grass, dogwood, elecampane, German chamomile, goldenseal, gotu kola, hops, kava (may help sleep without drowsiness), lavender aromatherapy, lemon balm, melatonin, sage, sassafras, skullcap, shepherd's purse, Siberian ginseng, St. John's wort, stinging nettle, wild carrot, wild lettuce, withania root, and yerba mansa. Caution is advised while driving or operating machinery. Valerian may have effects that counteract stimulation caused by caffeine.

A brief episode of confusion was reported in one patient during use of valerian with loperamide (Imodium®) and St. John's wort ( Hypericum perforatum L.). Nausea, sweating, muscle cramping, weakness, elevated pulse and high blood pressure were reported after a single dose of a combination product with St. John's wort, kava, and valerian. Valerian may interact with certain herbs and supplements that are metabolized by the liver.

About the Author

medlineplus.gov
MedlinePlus will direct you to information to help answer health questions. MedlinePlus brings together authoritative information from NLM, the National Institutes of Health (NIH), and other government agencies and health-related organizations. MedlinePlus also has extensive information about drugs, an illustrated medical encyclopedia, interactive patient tutorials, and latest health news.