Valerian Root & Possible Side Effects

Valerian has been used as a treatment for insomnia, anxiety, restlessness and stomach cramps for centuries. The root, which is obtained from the flowering grassland plant native to Europe and Asia, may reduce the amount of time it takes to fall asleep and may help you sleep better, although the results from studies have been mixed. While valerian seems to have benefits, it comes with possible side effects and interactions. Talk with your doctor before taking valerian root.

Valerian root may cause headache, sleepiness and irritability. (Image: Heike Rau/iStock/Getty Images)

The Nitty Gritty

Researchers aren't sure exactly how valerian works, but it is believed to cause an increase in gamma aminobutyric acid, or GABA - a chemical in the brain that helps regulate nerve cells and calm anxiety. This GABA-increasing effect is similar to the drug action of anti-anxiety medications like Xanax and Valium, although valerian is weaker.

Side Effects

Side effects of valerian are rare when taken in recommended dosages for a four- to six-week period. The most commonly reported short-term side effect associated with valerian is sleepiness. Long-term use of valerian root may cause headaches, restlessness, blurred vision, nausea, gastrointestinal upset and heart palpitations. In some cases, valerian may cause excitability and inability to sleep. Although uncommon, allergic reactions to valerian may occur. If you experience difficulty breathing, hives or swelling of the lips, tongue, throat or face, seek emergency medical attention. In rare cases, valerian root has been linked to liver damage. Let your doctor know if you are taking valerian so that your liver function can be monitored.

Do Not Mix With Medication

Valerian may increase the effectiveness of sedatives, such as antidepressants, alcohol, anti-convulsants, barbiturates, benzodiazepines and drugs to treat insomnia as well as sedating herbs, like chamomile, lemon balm and catnip. Valerian may interact with other drugs that are broken down by liver enzymes, such as statins, antihistamines and anti-fungals. The effects of anesthesia are increased by valerian root, so it is vital to inform your doctor and your anesthesiologist if you are taking valerian and having surgery.

Take Heed

You should speak with your doctor before using valerian root, especially if you have existing liver or kidney disease. Pregnant and breast-feeding women should not take valerian. Do not use valerian root while driving or operating heavy machinery. Valerian should not be used for longer than one month without the approval of your health care provider.