Valerian Root for Sleep: An Old Remedy With a Thin Modern Evidence Base

Valerian (Valeriana officinalis) has been used for insomnia since ancient Greece and Rome — it’s one of the oldest sleep remedies still sold today, marketed on that history as much as on any clinical trial. The traditional-use story is real and long. The modern trial evidence, once you actually weigh it the way a clinical guideline committee does, is thinner than the history suggests — and the field’s own 2024 synthesis of the evidence reached a notably blunter verdict than the individual studies underneath it.

Here’s what the research says, and where it pulls in different directions depending on how you measure “worked.”

The short version

• The largest recent meta-analysis of RCTs (21 trials, 1,433 participants) found valerian had a small-to-moderate effect on self-reported sleep quality (Pittsburgh Sleep Quality Index score improvement, SMD = −1.21) and improved the odds of self-reported better sleep quality and duration. That sounds like a real effect.
• But when the same trials were checked with objective measurements — actigraphy, polysomnography, the tools that don’t rely on what someone remembers about how they slept — valerian showed no significant effect on total sleep time or sleep efficiency, and only one secondary measure (time spent in NREM stage 3 sleep) reached significance.
• A 2024 umbrella review — a review of reviews, pooling 8 systematic reviews and 5 meta-analyses of the whole valerian-for-insomnia literature — concluded there is “no evidence of efficacy” for treating insomnia, despite acknowledging the same subjective-improvement pattern above. That’s the field’s own highest-level synthesis being more skeptical than any single meta-analysis underneath it.
• The American Academy of Sleep Medicine’s 2017 clinical practice guideline explicitly recommends against using valerian for chronic insomnia in adults — the same guideline body that recommends against melatonin for the same use, for similar reasons: the trial base doesn’t clear the bar for a general treatment recommendation.
• Safety looks good short-term, but valerian has a real, well-documented withdrawal syndrome if stopped abruptly after regular use — a fact that sits awkwardly next to how it’s usually marketed as a gentle, non-habit-forming alternative to sleep medication.
• A specific methodological problem, not just a general “more research needed”: valerian has a strong, distinctive odor that multiple reviewers say makes properly blinding placebo-controlled trials difficult — meaning some of the subjective-improvement signal above may reflect participants correctly guessing which pill they got, not a pharmacological effect.

What valerian studies actually test

Valerian is used as dried root/rhizome extract, most commonly at 300–600 mg taken before bed, sometimes for as little as a single night and sometimes for several weeks. Trials vary widely in preparation (aqueous extract, ethanol extract, whole root), dose, and how “sleep quality” gets measured — a heterogeneity the meta-analyses themselves flag as their primary source of statistical noise.

The subjective-vs-objective gap is the central finding

The 2023 meta-analysis (Zhang, Xu, and colleagues, Current Sleep Medicine Reports) pooled 21 RCTs and found valerian improved subjective outcomes clearly: PSQI score (SMD = −1.21, 95% CI −1.92 to −0.51), self-reported sleep-quality improvement (RR = 1.37, 95% CI 1.13–1.68), and self-reported sleep duration (RR = 1.27, 95% CI 1.02–1.57). All three of those are things people reported about their own sleep, not measured directly.

For objective sleep parameters — the subset of included trials that used actigraphy or sleep-lab measurement — the only significant finding was increased time in NREM stage 3 sleep (SMD = 0.89, 95% CI 0.35–1.43), a specific, secondary sleep-architecture measure. Total sleep time and sleep efficiency, the outcomes most people actually care about, did not improve significantly on objective measurement in this pooled analysis.

That gap — real subjective improvement, not confirmed objectively — is exactly the pattern that shows up across herbal sleep aids generally, and it’s why we’re not rating valerian higher than Limited despite the PSQI numbers looking sizable on their own.

The umbrella review: a more skeptical verdict from a higher vantage point

Valente et al.’s 2024 umbrella review (European Neuropsychopharmacology) sits a level above individual meta-analyses — it pooled 8 systematic reviews, 5 of them with their own meta-analyses, to assess the whole body of evidence at once. Its stated conclusion: valerian shows no evidence of efficacy for treating insomnia, even while acknowledging that subjective sleep-quality measures improved in multiple of the underlying meta-analyses. We read this finding via search-result summaries and a research-database entry, not the full original paper, so we’re presenting its topline conclusion with that caveat rather than citing specific numbers from it we haven’t verified ourselves.

This is a genuinely useful case study in how evidence synthesis can disagree with itself depending on the bar being applied: a single meta-analysis pooling raw effect sizes can look favorable, while a review of reviews — weighing study quality, blinding, and consistency across the whole literature — reaches a flatly more skeptical conclusion from the same underlying trials.

A guideline body has already weighed in, and said no

NCCIH’s own fact sheet on valerian states plainly that “the evidence on whether valerian is helpful for sleep problems is inconsistent,” and cites the American Academy of Sleep Medicine’s 2017 clinical practice guideline, which recommends against using valerian for chronic insomnia in adults. This is the same guideline, and the same “recommends against” verdict, we already flagged for melatonin’s general-insomnia use in our melatonin article — a pattern worth noticing: two of the most commonly marketed “natural sleep aid” ingredients both fail to clear the bar for a formal clinical recommendation, for the same chronic-insomnia use case, from the same guideline body.

NCCIH is also explicit that there isn’t enough evidence to draw conclusions about valerian for anxiety, depression, premenstrual syndrome, dysmenorrhea, or stress — the other uses it’s traditionally promoted for beyond sleep. Three small studies suggest a possible benefit for menopause symptoms, but NCCIH says that’s not enough evidence to be certain either.

The withdrawal risk that cuts against the “gentle and natural” pitch

This is the complication we think is easiest to miss in valerian marketing, and worth surfacing directly rather than leaving in the safety section as a minor footnote. NCCIH’s fact sheet states that stopping valerian abruptly after chronic use can produce withdrawal symptoms — anxiety, irritability, heart disturbances, insomnia (the exact thing it’s taken for), and in rare cases hallucinations. That’s a real dependence-adjacent pattern, not a hypothetical one, and it sits uncomfortably next to how valerian is typically positioned in the market: as a mild, “not habit-forming” alternative to prescription sleep medication. We’re not aware of evidence that this withdrawal pattern is common or severe for most users at typical doses, but its existence at all is worth knowing before stopping valerian suddenly after weeks of regular use — taper rather than stop cold, and loop in a healthcare provider if you’ve been using it regularly for an extended period.

Safety and regulatory status

NCCIH describes valerian as generally safe for short-term use by most adults, with apparent safety at 300–600 mg/day for up to 6 weeks in the research reviewed; the safety of longer-term use is not established either way. Reported side effects include headache, stomach upset, mental dullness, excitability, uneasiness, and vivid dreams — a mixed bag that includes both sedation-type effects and, in some people, the opposite (excitability, uneasiness). Some people experience next-day grogginess, particularly at higher doses.

Because valerian may have a sedative effect, NCCIH advises against combining it with alcohol or other sedatives. In very rare cases, liver injury has been reported in people taking valerian, most often as part of combination products with other herbs rather than valerian alone — NCCIH is explicit that valerian’s long-term effect on liver function isn’t established either way. Little is known about safety in pregnancy or breastfeeding. As with every ingredient on this site, valerian is regulated as a dietary supplement, not a drug — it is not FDA-approved or FDA-reviewed for effectiveness before sale.

What we could not check

• We did not read the full text of the 2024 umbrella review (Valente et al.) — its topline conclusion is drawn from search-result summaries and a research-database entry, not the original paper, and is presented with that caveat rather than as a fully independently verified primary-source read.
• We did not independently verify the blinding-difficulty claim against a specific trial’s own methods section — it’s drawn from a clinical review (Taibi et al., Sleep Medicine Reviews, 2007) discussing the literature generally, not confirmed study-by-study.
• We did not test any product. We have no independent data on what’s actually in any specific valerian supplement sold today, including whether it’s standardized to valerenic acid content or what that would mean for comparability to the trial doses above.
• We did not evaluate valerian in combination with other herbs (hops, lemon balm, and similar pairings are common in commercial sleep products) — the evidence above is for valerian on its own, and combination-product evidence is a distinct question we haven’t reviewed here.

Who should talk to someone first

Anyone pregnant, breastfeeding, taking sedatives, benzodiazepines, or alcohol regularly, or managing a liver condition should talk to a healthcare provider before starting valerian, given the safety gaps NCCIH itself flags above. Anyone who has been taking valerian regularly for an extended period should taper rather than stop abruptly, given the documented withdrawal pattern. Nothing here is medical advice, and no one on our team is a clinician — stated plainly on our About page.

Our rating, and why

For sleep quality/insomnia: Limited. Under our evidence scale, this reflects a real, measurable subjective effect in pooled trial data that does not hold up as clearly under objective measurement, is undermined by a documented blinding-difficulty problem specific to this ingredient, and is explicitly rated “no evidence of efficacy” by the most recent umbrella-level synthesis of the field. A formal clinical guideline (AASM 2017) recommends against use for chronic insomnia. We’re not calling this “no effect” — the subjective data is real — but we’re not rating it above the bar the field’s own most careful reviewers have set.

For anxiety, menopause symptoms, PMS, and other traditional uses: Limited-to-Anecdotal. NCCIH is explicit that there isn’t enough evidence for anxiety, depression, PMS, or dysmenorrhea, and only a handful of small studies exist for menopause symptoms specifically. This is squarely the traditional-use-versus-controlled-evidence gap this piece set out to illustrate.

If a well-conducted, larger objective-measures trial changes this picture, or the umbrella review’s full methodology turns out to weight things differently than its topline conclusion suggests, this rating will be revisited.

Sources

1. National Center for Complementary and Integrative Health (NCCIH). Valerian: Usefulness and Safety. Fact sheet, last updated May 2025. https://www.nccih.nih.gov/health/valerian
2. Zhang X, Lu Y, Lv F, et al. Valerian for Insomnia on Subjective and Objective Sleep Parameters: a Meta-analysis of Randomized Controlled Trials. Current Sleep Medicine Reports. 2023;9:211-224. https://link.springer.com/article/10.1007/s40675-023-00259-4
3. Valente V, Machado D, Jorge S, Drake CL, Marques DR. Does valerian work for insomnia? An umbrella review of the evidence. European Neuropsychopharmacology. 2024;82:6-28. https://pubmed.ncbi.nlm.nih.gov/38359657/ (Read via search-result summaries and a research-database entry, not the full original paper — see “What we could not check.”)
4. Sateia MJ, Buysse DJ, Krystal AD, et al. Clinical practice guideline for the pharmacological treatment of chronic insomnia in adults: an American Academy of Sleep Medicine Clinical Practice Guideline. Journal of Clinical Sleep Medicine. 2017;13(2):307-349. (Same guideline cited in our melatonin article; recommends against valerian for chronic insomnia.)
5. Taibi DM, Landis CA, Petry H, Vitiello MV. A systematic review of valerian as a sleep aid: safe but not effective. Sleep Medicine Reviews. 2007;11(3):209-230. (Cited for the blinding/odor methodological limitation discussion.)