Hops: Sleep and the Valerian Combination

Table of Contents

1. The Question, Stated Narrowly
2. Why Hops Is Almost Always Combined
3. The Largest Trial: 184 Adults, Three Arms
4. A 2025 Trial With Sleep Trackers
5. Three Herbs Against a Prescription Drug
6. Two Negative Trials
7. The Non-Alcoholic Beer Study
8. What the Reviews Conclude
9. What the European Regulator Concluded
10. How Hops Might Act
11. Interactions and Cautions in the Research
12. What Remains Unknown
13. Key Research Papers
14. Connections

The Question, Stated Narrowly

Three different questions get blurred together when people talk about hops and sleep:

1. Does a valerian–hops combination improve sleep compared with a dummy pill? There are randomised trials of this, with modest and partly positive results.
2. Does hops on its own improve sleep? No randomised, placebo-controlled sleep trial of hops alone appears among the studies reviewed for this page. The European Medicines Agency reached the same conclusion: because the clinical studies used hops with valerian, firm conclusions on hops alone could not be drawn.
3. Does hops add anything to valerian? Answering this would need a trial comparing valerian alone with valerian plus hops. None is included here.

Keeping those three apart is the single most useful thing a reader can do with this evidence.

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Why Hops Is Almost Always Combined

Hops reach the clinic mostly as one ingredient of a calming formula. In the trials on this page hops appears with valerian; with valerian and passionflower; with fatty acids; and with a milk-protein hydrolysate, jujube, magnesium and vitamin B6. Reviews of botanical sedatives, including a German pharmacy-education review (Unger, 2007), discuss hops within this wider group of calming plants. Trials have tested the formulas as they are sold, rather than each ingredient one by one.

The result is that the "hops" sleep literature is really a literature of products. When a trial reports a benefit, the credit belongs to the whole recipe. When a trial is negative, it is equally a finding about the recipe, not about hops.

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The Largest Trial: 184 Adults, Three Arms

The most rigorous study is a multicentre, randomised, placebo-controlled trial run at nine sleep-disorder centres in the United States (Morin and colleagues, 2005). Its design:

• Who: 184 adults (110 women, 74 men, average age 44.3) with mild insomnia.
• What: two nightly tablets of standardised valerian (187 mg native extract) and hops (41.9 mg native extract) for 28 days; or placebo for 28 days; or the over-the-counter antihistamine sleep aid diphenhydramine (25 mg tablets) for 14 days followed by placebo.
• Measured: sleep diaries, overnight polysomnography in the sleep laboratory, clinician and patient ratings, and quality of life.

Results. Both active treatments produced modest improvements in sleep as people reported it in their diaries, but few comparisons with placebo were statistically significant. Valerian–hops gave slightly greater, non-significant, reductions in the time taken to fall asleep at day 14, and greater reductions than placebo at day 28. On polysomnography there were no significant group differences in any measure of sleep continuity, and no change in deep sleep or REM sleep with any treatment. People taking valerian–hops rated their insomnia as less severe than placebo at day 14, and the physical component of quality of life improved more than with placebo at day 28.

Safety. There were no serious adverse events, no significant residual (carry-over) effects, and no rebound insomnia when the tablets were stopped.

The authors summarised the result as a modest hypnotic effect. That is a fair word: the effect was real enough to show up in some diary measures, and small enough not to show up in the laboratory.

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A 2025 Trial With Sleep Trackers

A randomised, double-blind, placebo-controlled feasibility study in Switzerland enrolled 40 people with occasional sleep problems (Schicktanz and colleagues, 2025). After a 21-day run-in period, participants took either the valerian–hops extract coded Ze 91019 or placebo for 21 days, wearing consumer sleep trackers and completing daily online tests of reaction time and working memory.

• The study was designed mainly to test whether this kind of trial could be run; adherence was high.
• In exploratory analyses, tracked sleep duration increased by an average of 21.7 minutes a day more than with placebo, and the shortest night of the treatment period was 48.7 minutes longer.
• There was no significant effect on daytime cognitive performance, stress, tiredness, mood, quality of life or motivation.
• The product was well tolerated.

Two points of context: "exploratory" means these were not the pre-specified main test of the study, and several authors were employed by the product's manufacturer, as the paper's author list states. Consumer sleep trackers are less exact than laboratory sleep recording.

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Three Herbs Against a Prescription Drug

A double-blind randomised trial in India compared a tablet containing standardised extracts of valerian, passionflower and hops (coded NSF-3) with zolpidem 10 mg, a widely prescribed sleep drug, for two weeks in adults with primary insomnia sleeping less than six hours a night (Maroo and colleagues, 2013).

• 91 people were recruited and 39 in each group completed the study.
• Total sleep time, time to fall asleep, number of night awakenings and insomnia severity improved significantly in both groups, with no statistically significant difference between them.
• Daytime sleepiness scores did not change. Adverse events were mostly mild drowsiness: 12 with the herbal tablet and 16 with zolpidem; none was serious.

The trial had no placebo arm. "As good as zolpidem" in a small two-week study cannot rule out that both groups improved partly through expectation and the passage of time, which the placebo-controlled trials on this page show is large in insomnia. The authors themselves noted that whether benefits last, and whether dependence could develop with long-term use, remained to be explored.

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Two Negative Trials

Two randomised trials of other hop-containing mixtures found no benefit over placebo:

• Fatty acids plus hop extract (Cornu and colleagues, 2010). Adults aged 25 to 65 with chronic primary insomnia took two capsules a day of a supplement containing polyunsaturated fatty acids with hop extract, or olive-oil placebo, for a month. Sleep quality on the Leeds questionnaire was similar in both groups; sleep improved in 65% on the supplement and 62% on placebo. Actigraphy sleep efficiency rose from 72% to 76% and 75% respectively, and urinary melatonin measures did not differ. The authors concluded the supplement had no effect.
• A five-ingredient complex (Scholey and colleagues, 2017). 171 otherwise healthy adults with mild insomnia took a combination coded LZComplex3 — a milk-protein hydrolysate, jujube (Zizyphus), hops, magnesium and vitamin B6 — or placebo for two weeks, after a one-week placebo run-in. Sleep quality on the Pittsburgh index improved in both groups with no significant difference, and most secondary outcomes moved the same way in both. The authors noted that a marked placebo response and the short duration may have masked a small effect.

Neither trial was designed to test hops alone, so neither shows that hops does not work. What they do show is that adding hops to a formula does not guarantee a measurable effect, and that the placebo response in insomnia trials is large enough to swamp a small one.

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The Non-Alcoholic Beer Study

A Spanish study looked at hops in its most familiar form (Franco and colleagues, 2012). Seventeen healthy female nurses working rotating or night shifts drank 333 ml of non-alcoholic beer (0.0% alcohol) with supper for 14 days, and their sleep was measured with wrist actigraphy and compared with their own control period without beer.

• Time to fall asleep fell from 20.50 to 12.01 minutes on average.
• Total night-time activity, a marker of restlessness, was lower.
• State anxiety scores fell slightly (from 20.69 to 18.09).

The design limits what this can show: 17 people, no placebo beverage, no blinding (everyone knew what they were drinking), and a beer contains far more than hops. The authors attributed the effect to the hop components; the study itself did not test that attribution.

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What the Reviews Conclude

• Salter and Brownie, 2010. Of 16 studies of valerian or hops for primary insomnia published from 1950 to 2009, 12 associated valerian alone or with hops with improvements in some sleep measures, such as time to fall asleep and sleep quality. The reviewers urged caution because the study designs differed greatly, and called for more randomised, double-blind, placebo-controlled trials.
• Borrás and colleagues, 2021. Reviewing clinical trials of 23 plants and combinations from 2010 to 2020 for insomnia linked to anxiety, the authors judged valerian, passionflower and ashwagandha the most promising single plants, and the combination of valerian with hops and passionflower the best performer in clinical tests. They also stressed the need for more trials of standardised design.
• Yeom and Cho, 2024. A literature review of sleep supplements listed valerian, hops and melatonin as those most likely to help, while noting that the strength of evidence varies and that optimal doses, formulations and durations are not established.
• Kenda and colleagues, 2022. A review of plants for anxiety, depression and stress included hops among plants that clinical trials have consistently shown to relieve mild forms of these complaints.

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What the European Regulator Concluded

The EMA's Committee on Herbal Medicinal Products assessed hop strobile and classed it as a traditional herbal medicine for relief of mild symptoms of mental stress and to aid sleep. In its public summary the committee states that laboratory studies supported the use for sleep, that the clinical studies used combinations of hops and valerian so firm conclusions on hops itself could not be drawn, and that the traditional-use status rests on long use rather than trial evidence. The monograph covers adults and adolescents over 12. EMA: Lupuli flos

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How Hops Might Act

The proposed mechanisms remain hypotheses:

• 2-methyl-3-buten-2-ol. This volatile breakdown product of the hop bitter acids is often named as the sedative principle, with a proposed action on GABA, the brain's main inhibitory chemical messenger (as described in the introduction of Franco and colleagues, 2012).
• Calming effects in general. Reviews attribute the sleep effects of valerian, hops and similar supplements to modulation of neurotransmitter systems and sleep–wake regulation (Yeom and Cho, 2024), without pinning down a specific molecule for hops.

None of the human trials on this page measured any of these mechanisms in people.

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Interactions and Cautions in the Research

• Liver enzyme effects in the laboratory. In human liver preparations, valerian and valerian–hops extracts reduced glucuronidation of paracetamol (acetaminophen), oestradiol, morphine and testosterone; oestradiol glucuronidation at one position was inhibited by nearly 87% (Alkharfy and Frye, 2007). The authors suggested that valerenic acid, a valerian constituent, may contribute to the effect. These are test-tube findings; effects in people were not measured.
• Sedative combinations. LactMed states that hops can cause sedation and advises against combining it with other sedating drugs, and against its use in people with depression.
• Age. The EMA monograph limits hop strobile medicines to adults and adolescents over 12.
• Duration. The EMA summary states that if symptoms last more than two weeks or worsen, a doctor or qualified practitioner is to be consulted.

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What Remains Unknown

1. Whether hops alone improves sleep in a placebo-controlled trial.
2. Whether hops adds anything to valerian.
3. Which hop compound, if any, is responsible for a sleep effect.
4. Whether benefits persist beyond four weeks.
5. How hop-containing products compare with non-drug treatments for insomnia; no such comparison appears in these studies.

For the condition itself see Insomnia and Sleep Hygiene.

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Key Research Papers

1. Morin CM, Koetter U, Bastien C, et al. Valerian-hops combination and diphenhydramine for treating insomnia: a randomized placebo-controlled clinical trial. Sleep. 2005;28(11):1465-71. PubMed PMID: 16335333
2. Schicktanz N, Gerhards C, Schlitt T, et al. Effects of a Valerian-Hops Extract Combination (Ze 91019) on Sleep Duration and Daytime Cognitive and Psychological Parameters in Occasional Insomnia: A Randomized Controlled Feasibility Trial. Brain and behavior. 2025;15(6):e70600. PubMed PMID: 40462685
3. Maroo N, Hazra A, Das T. Efficacy and safety of a polyherbal sedative-hypnotic formulation NSF-3 in primary insomnia in comparison to zolpidem: a randomized controlled trial. Indian journal of pharmacology. 2013;45(1):34-9. PubMed PMID: 23543804
4. Cornu C, Remontet L, Noel-Baron F, et al. A dietary supplement to improve the quality of sleep: a randomized placebo controlled trial. BMC complementary and alternative medicine. 2010;10:29. PubMed PMID: 20569455
5. Scholey A, Benson S, Gibbs A, et al. Exploring the Effect of Lactium™ and Zizyphus Complex on Sleep Quality: A Double-Blind, Randomized Placebo-Controlled Trial. Nutrients. 2017;9(2). PubMed PMID: 28218661
6. Franco L, Sánchez C, Bravo R, et al. The sedative effect of non-alcoholic beer in healthy female nurses. PloS one. 2012;7(7):e37290. PubMed PMID: 22815680
7. Salter S, Brownie S. Treating primary insomnia - the efficacy of valerian and hops. Australian family physician. 2010;39(6):433-7. PubMed PMID: 20628685
8. Borrás S, Martínez-Solís I, Ríos JL. Medicinal Plants for Insomnia Related to Anxiety: An Updated Review. Planta medica. 2021;87(10-11):738-753. PubMed PMID: 34116572
9. Yeom JW, Cho CH. Herbal and Natural Supplements for Improving Sleep: A Literature Review. Psychiatry investigation. 2024;21(8):810-821. PubMed PMID: 39086164
10. Kenda M, Kočevar Glavač N, Nagy M, et al. Medicinal Plants Used for Anxiety, Depression, or Stress Treatment: An Update. Molecules (Basel, Switzerland). 2022;27(18). PubMed PMID: 36144755
11. Unger M. [Botanical sedatives]. Pharmazie in unserer Zeit. 2007;36(3):206-12. PubMed PMID: 17555057
12. Alkharfy KM, Frye RF. Effect of valerian, valerian/hops extracts, and valerenic acid on glucuronidation in vitro. Xenobiotica; the fate of foreign compounds in biological systems. 2007;37(2):113-23. PubMed PMID: 17484515
13. Hops. Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Institute of Child Health and Human Development; 2006–. PubMed PMID: 30000893

PubMed Topic Searches

1. PubMed: Valerian and hops insomnia trials
2. PubMed: Humulus lupulus and sleep
3. PubMed: 2-methyl-3-buten-2-ol and hop sedation

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Connections

• Hops (Humulus lupulus) — the main page for the plant
• Hops Benefits Deep Dive — the evidence ledger
• 8-Prenylnaringenin and Menopause — the hormone question
• Xanthohumol Research — the most-studied hop compound
• Dog Poisoning, Allergy and Beer — safety findings
• Valerian — the partner herb in most trials
• Valerian for Sleep Quality — valerian's own sleep evidence
• Passionflower for Sleep Quality — the third herb in several combinations
• Lemon Balm — another calming herb often combined with valerian
• Melatonin — the sleep hormone measured in one hop trial
• Insomnia — the condition itself
• Sleep Hygiene — non-drug approaches to sleep

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