Quick answer

Valerian appears safe for short-term use by most adults: NCCIH says it has been used with apparent safety at 300 to 600 mg a day for up to 6 weeks. Side effects include headache, stomach upset, mental dullness and vivid dreams. Rare liver injury has been reported, and long-term safety is unknown.^1,2

Key facts

Across 60 studies with 6,894 people, no serious adverse events were reported.³
A 2024 review of 8 systematic reviews judged valerian's safety profile good.⁴
NIH's lactation database has no data on valerian's safety for nursing mothers or their babies.⁵
FDA considers valerian generally recognized as safe for use in food.⁵

Side effects reported

Side effects of valerian include headache, stomach upset, mental dullness, excitability, uneasiness and vivid dreams.¹

In clinical trials, headaches, dizziness, itching and stomach upset were the most common effects reported, but people taking placebo reported similar effects.⁶

A minority of people in studies felt agitated or restless rather than calm, and in one study a higher dose of the same product raised anxiety while a lower dose did not.³

In one small study, people felt sleepier the morning after a 900 mg dose.⁶

Next-day alertness

In studies of healthy adults and older volunteers, single doses of standardized extracts from 100 to 1,600 mg did not impair thinking or reaction speed.³

A trial of 102 volunteers, run by the extract's maker, found the same for 600 mg in the evening: no slower reactions the next morning, after one dose or after two weeks.⁷

Liver

In very rare cases, liver injury has been reported in people taking valerian, most often in combination with other herbs. NIH's LiverTox database links valerian to rare instances of liver injury, and its long-term effect on the liver is unknown.^1,2

Because the reported cases mostly involved valerian combined with other herbs, it is hard to say which ingredient was responsible. Ask a doctor before using valerian if you have liver disease.^1,2

Stopping after long use

Some people may have withdrawal symptoms, including anxiety, irritability, heart disturbances, insomnia and, in rare cases, hallucinations, if they stop suddenly after long-term use.¹

Long-term daily users should plan stopping with a doctor rather than quitting overnight.¹

Alcohol, sedatives and other sleep aids

Ask your pharmacist or doctor first

NIH's Office of Dietary Supplements says valerian might add to the effects of sedatives and other medicines that slow the nervous system. It names benzodiazepines such as alprazolam, diazepam, lorazepam and triazolam, and barbiturates and other depressants such as phenobarbital, morphine and propofol. NCCIH says valerian should not be taken along with alcohol or sedatives.^1,6

Expected from how the two work, not shown in studies

NIH also names supplements with sedative properties: St. John's wort, kava and melatonin. Blends can combine several of these, and our own Sleep formula pairs valerian with melatonin, so read the full ingredient list of everything you take.⁶

Who should not take it, or should ask first

Children under 3: NIH says they should not take valerian, because the risks at that age have not been evaluated⁶
Pregnant or nursing women, unless a doctor advises it: the risks to a baby have not been evaluated^1,6
Anyone with surgery planned: NIH lists the anesthetic propofol among the medicines valerian might add to⁶
Anyone with long-lasting poor sleep: NCCIH reports that sleep medicine guidelines advised against valerian for chronic insomnia¹

On breastfeeding, NIH's lactation database says valerian is often not recommended because of theoretical concerns about some of its compounds, and that another option may be better, especially with a newborn or a baby born early.⁵

Questions people ask

Is valerian root safe to take every night?

For a few weeks it appears to be for most adults: NCCIH cites apparent safety at 300 to 600 mg a day for up to 6 weeks. Beyond that, long-term safety is unknown, and stopping suddenly after long use can bring withdrawal symptoms.¹

Can valerian cause weird dreams?

Yes. NCCIH lists vivid dreams among valerian's side effects, along with headache, stomach upset, mental dullness, excitability and uneasiness.¹

Does valerian cause weight gain?

None of the sources on this page lists weight gain among valerian's side effects. If you notice a change you did not expect, tell your doctor.^1,6

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Sources

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.