Understanding the Answer to: Does valerian have side effects?

October 8, 2025 •

4 min read

While often promoted as a natural sleep aid, research suggests that valerian is generally safe for short-term use, though the safety of long-term use is not well-established. Knowing the answer to “Does valerian have side effects?” is crucial for anyone considering this popular herbal supplement for insomnia or anxiety.

Quick Summary

Valerian is an herbal supplement associated with some potential adverse reactions, including headaches and digestive upset. It can also interact with other medications, particularly sedatives and alcohol, increasing the risk of over-sedation. Long-term use or abrupt cessation can lead to withdrawal symptoms.

Key Points

Common Side Effects: Mild reactions to valerian can include headache, stomach upset, and next-day grogginess, though it is generally well-tolerated.
Risky Drug Interactions: Valerian poses a significant interaction risk with alcohol, sedatives, and other central nervous system depressants due to its additive sedative effects.
Withdrawal Potential: Abruptly stopping chronic, high-dose valerian use can cause withdrawal symptoms like anxiety and irritability; a gradual dose reduction is advised.
Hepatotoxicity Warning: Though rare, valerian has been implicated in cases of liver injury, so individuals with liver disease should avoid it and others should be aware of potential signs of liver issues.
Long-Term Safety Unknown: The safety profile for long-term valerian use is not established, as most research focuses on short-term application.
Consult a Doctor: Always talk to a healthcare provider before taking valerian, especially if pregnant, breastfeeding, on other medications, or have underlying health conditions.

Common Adverse Effects of Valerian

While valerian root is typically well-tolerated, some individuals may experience mild and transient side effects. These reactions are generally not severe but are worth noting, especially for those sensitive to herbal supplements. The most commonly reported issues include headaches, stomach upset, and next-day grogginess. Unlike many conventional sleep aids, valerian is often noted for not causing a "hangover" effect at standard dosages, but this can occur, particularly with higher doses.

Some people may experience an unexpected reaction, such as a feeling of restlessness or excitability, which can be counterproductive when trying to achieve relaxation or sleep. Other less frequent, but still possible, side effects include vivid dreams or abnormal heartbeats. The potential for side effects underscores the need for individuals to start with a low dose and monitor their body’s response.

Important Drug and Substance Interactions

A significant safety concern with valerian involves its potential to interact with other drugs and substances, primarily due to its sedative properties. This is particularly relevant for those taking prescription medications for sleep, anxiety, or other conditions affecting the central nervous system (CNS).

Alcohol

Combining valerian with alcohol is strongly discouraged. Both substances are CNS depressants, and taking them together can lead to an additive sedative effect. This can cause excessive drowsiness, coordination issues, and potentially dangerous respiratory depression.

Sedatives and CNS Depressants

Valerian may increase the effects of other sleep-inducing or anxiety-reducing medications, including benzodiazepines like alprazolam (Xanax) and diazepam (Valium), barbiturates, and narcotics. This combination can increase the risk of over-sedation and breathing problems. Anyone taking these medications should consult a doctor before adding valerian to their regimen.

Liver-Metabolized Medications

Valerian can impact the liver's ability to metabolize certain medications, specifically those processed by the cytochrome P450 enzyme systems (CYP3A4 and CYP2D6). This can alter the effects and side effects of these drugs. One case report detailed acute renal failure in a patient taking valerian with the statin drug rosuvastatin, which is metabolized by the liver, highlighting the potential for serious interactions.

Valerian Risks and Precautions

Beyond basic side effects and interactions, several important precautions should be considered before and during valerian use. Since herbal supplements are not as strictly regulated by the FDA as prescription drugs, their quality and consistency can vary.

Considerations for Long-Term Use and Withdrawal

Research on valerian primarily focuses on short-term use (up to 4-6 weeks), and the safety of long-term use is largely unknown. For those who use valerian chronically, abruptly stopping the supplement could trigger withdrawal symptoms. These can include anxiety, irritability, insomnia, and rapid heartbeat. A gradual reduction in dosage is recommended after extended use.

Hepatotoxicity Concerns

While rare, cases of liver injury have been reported in connection with valerian use, often when combined with other herbal supplements. Individuals with pre-existing liver disease should avoid taking valerian to prevent potential complications.

Special Populations

There is insufficient evidence regarding the safety of valerian in pregnant or breastfeeding women, so it should be avoided by these groups. Similarly, valerian has not been adequately evaluated for safety in children under the age of three.

A Comparison of Valerian and Melatonin Side Effects


Feature	Valerian Root	Melatonin
Primary Use	Traditionally used for sleep, anxiety, and stress.	Primary for resetting the body’s sleep-wake cycle.
Typical Side Effects	Headache, dizziness, upset stomach, next-day drowsiness, vivid dreams.	Daytime sleepiness, dizziness, headache, nausea.
Drug Interactions	Significant interaction risk with alcohol, sedatives, and liver-metabolized drugs.	Can interact with anticoagulants, immunosuppressants, and some blood pressure medications.
Withdrawal Potential	Possible withdrawal symptoms after abrupt cessation of long-term, high-dose use.	Dependence and withdrawal are generally not reported, though safety of long-term use is still unknown.
Pregnancy/Breastfeeding	Not recommended due to insufficient safety data.	Not recommended due to insufficient safety data.

Conclusion: Cautious Use is Advised

While valerian is considered relatively safe for short-term use by many adults, answering the question, “Does valerian have side effects?” requires recognizing its potential for adverse reactions and interactions. The supplement is not without risks, including gastrointestinal issues, next-day drowsiness, and, in rare instances, more serious issues like liver injury or withdrawal symptoms.

It is imperative to talk to a healthcare provider before taking valerian, especially if you have pre-existing medical conditions, are pregnant or breastfeeding, or take other medications. Because valerian is not regulated like prescription drugs, quality and consistency can vary significantly among products. For those seeking alternatives for sleep issues, addressing underlying causes and exploring behavioral therapies can often be more effective and safer. This herbal remedy should be used with informed caution and proper medical guidance.

For more information on the efficacy and safety of herbal supplements, consult the National Center for Complementary and Integrative Health (NCCIH)(https://www.nccih.nih.gov/health/valerian).

Frequently Asked Questions

Yes, although it's rare, withdrawal symptoms such as anxiety, irritability, and rapid heartbeat have been reported following the abrupt cessation of long-term, high-dose valerian use. To avoid this, it is best to reduce the dosage slowly over a week or two.

No, it is not safe. Combining valerian with alcohol or other central nervous system depressants, such as benzodiazepines or narcotics, can dangerously increase their sedative effects and lead to excessive drowsiness or breathing problems.

In very rare cases, liver injury has been reported in individuals taking valerian, particularly when combined with other herbs. Anyone with liver disease should avoid valerian, and all users should be vigilant for signs of liver problems, like jaundice or stomach pain.

Individuals who are pregnant or breastfeeding, children under three, and people with liver disease should not take valerian without medical supervision due to insufficient safety data or potential risks. You should also avoid it if you need to drive or operate machinery.

The most common side effects are mild and include headache, dizziness, stomach upset, and, in some cases, next-morning drowsiness. Some users may also experience restlessness or vivid dreams.

Valerian is generally considered safe for short-term use, typically up to 4 to 6 weeks. The long-term safety is not well-researched, so it is best to use it for limited periods and under a doctor's guidance.

Yes, valerian can interfere with various prescription drugs, particularly those that are also metabolized by the liver. It is crucial to inform your doctor about your valerian use to ensure it won't negatively interact with your other medications.