Valerian Side Effects and Warnings

Safety Issues

Valerian is on the FDA's GRAS (generally recognized as safe) list and is approved for use as a food. In animals, it takes enormous doses of valerian to produce any serious adverse effects. ¹ Valerian has shown an excellent safety profile in clinical trials. ² In a suicide attempt, one young woman took approximately 20 g of valerian (20 to 40 times the recommended dose). Only mild symptoms developed, including stomach cramps, fatigue, chest tightness, tremors, and light-headedness. All of these resolved within 24 hours, after two treatments with activated charcoal. ³ The woman's lab tests—including tests of her liver function—remained normal. Keep in mind that this does not mean that you can safely exceed the recommended dose!

One report did find toxic results from herbal remedies containing valerian mixed with several other herbal ingredients, including skullcap . Four individuals who took these remedies later developed liver problems. ⁴ However, skullcap products are sometimes contaminated with the liver-toxic herb germander, and this could have been the explanation.

There have also been about 50 reported cases of overdose with a combination preparation called Sleep-Qik, which contains valerian as well as conventional medications. ⁵ Researchers specifically looked for liver injury, but found no evidence that it occurred.

There are some safety concerns about valepotriates, constituents of valerian, because in test tube studies they have been found to affect DNA and cause other toxic effects. However, valepotriates are not present to a significant extent in any commercial preparations. ⁶ Although no animal studies or controlled human trials have found evidence that valerian causes withdrawal symptoms when stopped, one case report is sometimes cited in support of the possibility that this might occur. ⁷ It concerns a 58-year-old man who developed delirium and rapid heartbeat after surgery. According to the patient's family, he had been taking high doses of valerian root extract (about 2.5 g to 10 g per day) for many years. His physicians decided that he was suffering from valerian withdrawal. However, considering the many other factors involved (such as multiple medications and general anesthesia), it isn't really possible to conclude that valerian caused his symptoms.

In clinical trials, use of valerian has not been associated with any significant side effects. A few people experience mild gastrointestinal distress, and there have been rare reports of people developing a paradoxical mild stimulant effect from valerian.

Valerian does not appear to impair driving ability or produce morning drowsiness when taken at night. ^{8 9 10} As noted above, most studies have failed to find any immediate sedative effect with valerian. However, one study reported finding mild impairment of attention for a couple of hours after taking valerian. ¹¹ For this reason, it isn't a good idea to drive immediately after taking it.

There have been no reported drug interactions with valerian, and two studies found reasons to believe that valerian should not raise or lower the blood levels of too many medications. ¹² Nonetheless, there are at least theoretical concerns that valerian might amplify the effects of sedative drugs. A 1995 study was somewhat reassuring on this score because it found no interaction between alcohol and valerian. ¹³ However, animal studies have found that valerian extracts may prolong the effects of some sedatives, ¹⁴ and there have been some worrisome case reports suggesting that the combination of valerian and alcohol can lead to excessive sedation in some people. ¹⁵ For this reason, we recommend that you do not combine valerian with central nervous system depressants except under doctor’s supervision.

Safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established.

Interactions You Should Know About

If you are taking sedative drugs such as benzodiazepines ; don't take valerian in addition to them, except under physician supervision.