Results from several small or short-term studies indicate that valerian — a tall, flowering grassland plant — may reduce the amount of time it takes to fall asleep and help you sleep better. However, not all studies have shown valerian to be effective, and there may be some dangers.

Before you decide to take a valerian supplement for insomnia, consider the following:
•Medication may not be the answer for insomnia. Cognitive behavioral therapy — for instance, replacing worries about not sleeping with positive thoughts — may be more effective and safer than medications for dealing with chronic insomnia.
•Product claims may be misleading. Be a smart consumer and do a little homework. Don’t just rely on a product’s marketing. Look for objective, research-based information to evaluate a product’s claims. Of the many valerian species, only the carefully processed roots of the most widely studied species, Valeriana officinalis, are known to contain the most effective mix of active compounds.
•Dosage is unclear. Valerian seems to be most effective after you take it regularly for two or more weeks. Since there have been relatively few rigorous studies involving valerian, it’s not clear what dose is most effective or for how long you should take a particular dose.
•Possible side effects exist. Although valerian is thought to be fairly safe, headache, dizziness, gastrointestinal problems and sleeplessness can occur. Valerian may not be safe if you’re pregnant or breast-feeding. If you have liver disease, avoid taking valerian.
•Drug interactions are possible. Valerian may increase the effects of other sleep aids. It also increases the sedative effect of other depressants, such as alcohol and diazepam (Valium). Check with your doctor if you’re thinking of taking a valerian supplement to make sure that it won’t interact with any other medications you’re taking.

Ultimately, persistent insomnia indicates a problem, such as a medical or psychological condition or poor sleep habits. If you have persistent insomnia, talk to your doctor about possible causes and treatment strategies or consider getting an evaluation at a sleep medicine center that’s accredited by the American Academy of Sleep Medicine.