Valerian Side Effects: What to Know Before You Take It

For most adults, valerian is not harmful when taken at the doses stated on the label and for short periods. The available reviews found no serious adverse events associated with its use in people aged 7 to 80 ¹, and one systematic review described it as "safe, but not effective" for sleep ². That does not mean it is harmless: the effects are real, there are reports of drowsiness and gastrointestinal discomfort, and there are groups — pregnant women, children, people with liver disease or taking certain medicines — in which the risk changes and the decision should be made with a healthcare professional.

This page answers the most common safety questions: which effects are expected, what constitutes "too much", what it interacts with and when to stop. If you are looking for information on effectiveness, see the article on how valerian works.

What the evidence says about valerian safety

The largest systematic review on the subject pooled 60 studies with 6,894 participants and concluded that there were no serious adverse events associated with taking valerian in people aged 7 to 80 ¹. An earlier systematic review, with 16 randomised placebo-controlled trials in 1,093 patients, suggested that valerian may improve sleep quality without producing side effects, although the authors noted important methodological problems in the studies and considerable variation in the doses and preparations used ³.

There is, however, a signal that deserves attention: in a meta-analysis of 14 randomised trials with 1,602 participants with insomnia, the number of adverse events per person was higher in the valerian group than in the placebo group ⁴. This does not indicate severity — it indicates that valerian is not "neutral" and that some users experience effects. An umbrella review, which looked only at systematic reviews, reinforced that the safety profile is good, but that effectiveness for insomnia is not demonstrated ⁵.

Which side effects are most common

The effects described in the literature and in clinical reports are generally mild and reversible:

• Daytime drowsiness, especially if taken in the morning or if you are sensitive to the sedative effect.
• Dizziness or light-headedness.
• Headache.
• Gastrointestinal discomfort — nausea, gas, feeling of a heavy stomach.
• Dry mouth.

A randomised, double-blind, placebo-controlled trial with 102 volunteers specifically assessed the impact of 600 mg of valerian root extract on reaction time, alertness and concentration. Neither a single evening dose nor 14 days of use significantly impaired these abilities ⁶. This is reassuring for anyone worried about feeling "foggy" the next day, but it does not remove individual risk: if you feel drowsy, do not drive or use machinery until you know how you react.

A crossover trial with a single 1,600 mg dose of valerian found no significant differences in sobriety tests or in a driving simulator, but the authors admitted that the study may have had insufficient statistical power to detect differences ⁷. In other words: the evidence does not show a clear driving risk, but it does not safely rule one out either.

Is "too much" the same as "dangerous"?

No. There is a difference between a dose that causes discomfort and a dose that poses serious danger. Valerian does not have a narrow therapeutic window like some medicines, and there are no reliable reports of death from valerian alone. There are reports of intense drowsiness, dizziness and malaise in people who took amounts well above the recommended level.

The practical problem is different: the amount of extract varies widely between products and between studies, and extract quality is one of the reasons given for inconsistent results ¹. The label dose is therefore the limit you should respect. If you feel you need more to get an effect, do not increase it on your own — talk to a healthcare professional. More is not better.

Who should take extra care

Some groups are not necessarily prevented from taking valerian, but the risk-benefit ratio should be assessed by a doctor or pharmacist:

• Pregnant and breastfeeding women: there are not enough data to guarantee safety. Prudence dictates avoiding it and talking to a healthcare professional.
• Children: the effect on the developing nervous system is not well studied. The meta-analysis that assessed safety included participants aged 7 and over ¹, but that is not the same as a paediatric recommendation. Never give doses to children without a healthcare professional's instruction.
• People with liver disease: valerian is metabolised by the liver and there are rare cases of liver injury associated with its use. If you have liver problems, do not take it without medical supervision.
• People with psychiatric disorders or taking psychotropic medicines: valerian acts on the GABA system, the same target as many anxiolytics and some antidepressants. Do not combine them without talking to the doctor who is treating you.
• Anyone scheduled for surgery: inform the anaesthetist and discuss stopping before the operation.

If you take valerian and are going to have surgery, the prudent recommendation is to stop the supplement at least two weeks beforehand and inform the anaesthetist, since there may be an interaction with anaesthesia and with the medicines used during the procedure.

If you are pregnant or breastfeeding, see also the specific article on valerian in pregnancy.

Interactions with medicines: what is known

Valerian does not interact with everything, but there are clinically significant interactions. The most relevant involve substances that also affect the central nervous system or that are metabolised by the liver:

• Sedatives and anxiolytics (benzodiazepines, zolpidem and other sleep-inducing medicines): the combined effects can cause excessive drowsiness and difficulty waking up.
• Antidepressants, especially those that affect serotonin or GABA: the effect may be unpredictable.
• Medicines for high blood pressure: valerian can lower blood pressure, and combining it with antihypertensives can cause dizziness.
• Alcohol: alcohol enhances the sedative effect. Avoid combining them.
• Medicines metabolised by the liver: valerian can interfere with liver enzymes, altering the rate at which other medicines are processed.

If you take any medicine, speak to your pharmacist before starting. There are further details in the article on valerian and medicine interactions.

Warning signs: when to stop and seek help

Most effects are harmless, but there are signs that should not be ignored. If you experience any of these, stop taking it and seek medical advice:

• Jaundice — yellowing of the skin or whites of the eyes, dark urine, pale stools.
• Severe palpitations or irregular heart rhythm.
• Confusion, disorientation or difficulty speaking.
• Difficulty breathing or chest tightness.
• Allergic reaction — skin rash, severe itching, swelling of the face or lips.
• Extreme drowsiness that does not go away, even hours after waking.

These symptoms are rare, but if they appear do not wait for them to resolve. Take the product with you when you seek help.

What if you take valerian in gummies?

There are no studies directly comparing valerian gummies with tablets or capsules, so it is not possible to say that they are equivalent or superior. What is known is that the active substance is the same and that the format has its own practical considerations.

Gummies usually contain sugars or polyols. Polyols such as maltitol can cause gastrointestinal discomfort when consumed in excess — an effect that can be confused with that of valerian itself. If you have diabetes or are managing your weight, check the label. And because they are chewed, contact with the teeth is greater: if you take them every night, brush your teeth afterwards.

In addition, the dose per gummy is fixed and the taste makes it easy to take one too many. Resist. Keep the bottle out of the reach of children: gummies look like sweets and a child could eat several without realising. If that happens, contact a doctor, pharmacist or poisons information centre immediately.

If you suspect a child has accidentally taken too many, do not wait to see what happens: contact your doctor, pharmacist or poisons information centre straight away.

If you are looking for a product from the range, you can browse valerian gummies or the sleep and relaxation category. Always read the label: the amount of extract varies between brands.

What we still do not know

Valerian has been used for centuries, but modern research has gaps that must be acknowledged.

We do not know what the ideal dose is for each person. Studies use different extracts, with different concentrations of active compounds, which makes results hard to compare — and this variability is cited as one of the causes of inconsistent results ¹. We also do not know whether long-term use over months or years is safe: most trials cover weeks, not decades. And the full range of medicine interactions is unknown; those identified are the most likely, not the only ones.

These uncertainties do not make valerian dangerous. They mean it must be used with respect, like any substance with biological effects.

Myths and truths about valerian safety

Claim	What the evidence indicates
"It is a weak sedative, almost homeopathic"	False. It acts on the GABA system, the same target as many anxiolytics, and has measurable effects 8.
"It works for everyone"	False. Study results are mixed and some people feel no difference 2.
"It is addictive like a benzodiazepine"	There is no evidence of physical or psychological dependence in that sense. There are reports of symptoms after stopping prolonged use, but the data are limited.
"It interacts with medicines"	True. The most relevant interactions are with sedatives, antidepressants, antihypertensives and alcohol.
"It is natural, so it cannot do harm"	False. "Natural" does not mean harmless. Valerian has bioactive compounds and can cause side effects.
"The evidence is solid"	Partially. Some studies suggest subjective improvement in sleep quality, but effectiveness for insomnia is not demonstrated 5.

What to do next

If you are thinking about taking valerian, begin by talking to your pharmacist or doctor, especially if you take medicines, have a chronic condition or are pregnant or breastfeeding. Read the product label, respect the stated dose and monitor how you feel in the first few weeks. If you notice persistent effects or any warning sign, stop and seek help.

Valerian is a tool, not a magic solution. Sleeping well depends on many factors — routine, environment, stress, diet and physical activity. If valerian helps, that is good. If it does not, do not force it: there are other options, and a professional can guide you. To understand better what the science says about effectiveness, see the article on valerian benefits.

Frequently asked questions

Is valerian bad for your liver?

There are rare cases of liver injury associated with valerian use, but most reviews found no serious adverse events. If you have liver disease or take medicines metabolised by the liver, talk to a doctor before taking it. Signs such as yellowing of the skin or eyes require immediate medical assessment.

Can I take valerian every day?

Most studies assess short periods of weeks, and there are no solid data on use over months or years. If you intend to take it continuously, it is prudent to talk to a healthcare professional and take breaks. Do not increase the dose on your own if you feel the effect is wearing off.

Does valerian make you drowsy the next day?

In a trial with 102 volunteers, neither a single 600 mg evening dose nor 14 days of use significantly impaired reaction, alertness and concentration. Even so, individual response varies: if you feel drowsy, do not drive or use machinery until you know how you react.

Does valerian interact with alcohol?

Yes. Alcohol enhances the sedative effect of valerian, and the combination can cause excessive drowsiness and lack of coordination. The most sensible approach is to avoid drinking alcohol on nights when you take valerian.

Is valerian safe in pregnancy and breastfeeding?

There are not enough data to guarantee safety during these periods. The prudent recommendation is to avoid it and talk to a healthcare professional before taking any valerian supplement. The same applies to children, who should not be given doses without medical instruction.

Is valerian addictive?

There is no evidence of physical or psychological dependence like that seen with opioids or benzodiazepines. There are reports of symptoms after stopping prolonged use, but the data are limited. If you have been taking it for a long time, reduce gradually and talk to a professional if you notice symptoms.