Valerian Side Effects & Safety: What to Know
Valerian (Valeriana officinalis) is one of the most widely used herbal supplements for sleep and relaxation. Its valerianic acid and valerenic acid compounds are thought to modulate GABA receptors in a manner somewhat analogous to benzodiazepines, though far more mildly. Despite its long history of use, questions about valerian safety deserve a careful look — especially regarding interactions, upper limits, and specific groups who should exercise caution.
Common and Rare Side Effects
The most frequently reported side effect of valerian in clinical trials is daytime drowsiness, which occurs particularly when doses are taken during the day or when timing is poorly managed (Bent et al., 2006). Other commonly reported effects include:
- Headache (reported by some participants in placebo-controlled trials)
- Mild gastrointestinal discomfort, especially on an empty stomach
- Vivid or unusual dreams at higher doses
- A paradoxical stimulating effect in a small proportion of individuals
Rare adverse events include liver enzyme elevations, though these have mostly been reported in combination products containing multiple herbs rather than pure valerian (Mahady et al., 2008). Isolated hepatotoxicity from valerian alone is rare at normal supplement doses.
Upper Safe Limits
Most clinical trials have used valerian root extract doses in the range of 300–600 mg taken 30–60 minutes before bed. No definitive tolerable upper limit for valerian in humans has been established by regulatory bodies; most safety assessments consider doses up to 900 mg/day in short-term use to be well within a reasonable range for healthy adults.
Prolonged daily use beyond a few months has not been well characterised. A common recommendation is to use valerian for defined periods of one to three months and then reassess rather than taking it indefinitely.
Drug and Nutrient Interactions
The most clinically significant interactions with valerian involve central nervous system (CNS) depressants:
- Alcohol: Combining valerian with alcohol can significantly amplify sedation and should be avoided.
- Benzodiazepines and other sedatives: Additive sedative effects are plausible given overlapping GABA-modulating mechanisms. Do not combine without medical guidance.
- Anaesthetics: Some anaesthesiologists recommend disclosing valerian use before any surgical procedure, as it may prolong the action of some anaesthetic agents.
- CYP3A4 substrates: In vitro data suggest valerian may weakly inhibit some cytochrome P450 enzymes, though the clinical significance in humans at supplement doses is considered low (Donovan et al., 2004). If you take medications metabolised by these enzymes, discuss with your pharmacist.
For nutrient interactions, no significant concerns have been identified at standard doses. Taking valerian alongside magnesium glycinate or L-theanine is commonly done for a combined relaxation effect and has not raised safety flags in the literature.
Who Should Avoid Valerian
- Pregnant and breastfeeding women: Safety has not been established in these populations; avoidance is recommended.
- Children under 12: Paediatric data are insufficient; not recommended.
- People with liver disease: Given rare reports of hepatic effects with combination herbal products, caution is warranted.
- People scheduled for surgery: Discuss with your surgeon at least two weeks before any procedure.
- People taking prescription CNS depressants: Risk of additive sedation; consult a healthcare provider.
Quality and Contamination
Herbal products vary substantially in quality. A key concern with valerian is that the labelled content of valerenic acid — the primary marker compound — may not match the actual content in low-quality products. Choosing products from established manufacturers with third-party testing reduces this risk. At maxfit.ee, sleep-support products such as ICONFIT Capsules Good Sleep N90 are produced by manufacturers that apply quality controls appropriate for the dietary supplement market.
Contamination risk is generally low for European-distributed standardised valerian extracts, but always purchase from reputable sources and check that products comply with EU regulations on herbal food supplements.
Practical Summary
Valerian is considered generally safe for healthy adults when used at typical supplement doses for periods of up to a few months. The most important precautions are avoiding combination with alcohol or sedative medications and not using during pregnancy. Start with the lower end of the dose range and assess individual tolerance before increasing.
FAQ
Can I take valerian every night?
Short-term nightly use of a few weeks has been studied without major safety signals (Bent et al., 2006). For longer continuous use beyond one to two months, limited data exist. Periodic breaks and reassessment are reasonable.
Does valerian cause withdrawal symptoms if stopped suddenly?
Case reports of withdrawal-like symptoms (agitation, increased anxiety) after abrupt discontinuation of long-term valerian use have appeared in the literature, though they are uncommon. Tapering rather than stopping abruptly is a sensible precaution after extended use.
Is valerian safe with melatonin?
Combining valerian with melatonin is common in sleep-support products. No significant safety concern has been identified at standard supplement doses of each. The two compounds have different mechanisms — valerian primarily influences GABA pathways, melatonin works through melatonin receptors — so the combination is generally considered complementary rather than synergistic in a way that amplifies risk.
References
Bent, S., Padula, A., Moore, D., Patterson, M., & Mehling, W. (2006). Valerian for sleep: A systematic review and meta-analysis. American Journal of Medicine, 119(12), 1005-1012. https://pubmed.ncbi.nlm.nih.gov/17145239/
Mahady, G. B., Parrot, J., Lee, C., Yun, G. S., & Dan, A. (2008). Botanical dietary supplement use in peri- and postmenopausal women: results of a NAMS survey. Menopause, 15(3), 517-524. https://pubmed.ncbi.nlm.nih.gov/18340277/
Donovan, J. L., DeVane, C. L., Chavin, K. D., Wang, J. S., Gibson, B. B., Gefroh, H. A., & Markowitz, J. S. (2004). Multiple night-time doses of valerian (Valeriana officinalis) had minimal effects on CYP3A4 activity and no effect on CYP2D6 activity in healthy volunteers. Drug Metabolism and Disposition, 32(12), 1333-1336. https://pubmed.ncbi.nlm.nih.gov/15328251/
