Does zinc help you sleep?

Possibly a little, and the evidence is thin. The only systematic review of zinc and sleep, published in 2024, found 8 randomized trials and could not pool them into one number. In adults, 3 of 5 trials reported better sleep quality scores: two at 30 mg a day for 10 to 12 weeks in older adults and dialysis patients, and one in ICU nurses at 220 mg of zinc sulfate every 72 hours for a month. Two trials found no change, and the two adult trials that measured sleep length found no change in it.

Unsettled. Zinc for sleep is unsettled. The trials are few and small, five of the eight come from one country, and they tested very different people at very different doses. The doses that seemed to work sit close to the 40 mg a day upper limit for adults.

What the trials found

Sleep quality

The 2024 review lists the adult trials that improved scores on the Pittsburgh Sleep Quality Index, a questionnaire. In dialysis patients, 30 mg of zinc gluconate a day for 12 weeks improved sleep quality against placebo. Older adults on 30 mg a day for 10 weeks also improved. The review reports no pooled size for any of this. Its authors concluded that most trials using more than 30 mg a day for 12 weeks or longer in adults saw better sleep quality, and called for larger trials.

In a 1-month double-blind trial of 54 ICU nurses, 220 mg of zinc sulfate every 72 hours lowered total sleep quality scores and sleep latency scores against placebo, where lower means better sleep. The abstract gives no figures for the size of the change. The review gives the dose as about 73 mg of zinc sulfate a day, not as zinc itself, so it cannot be set directly against the upper limit.

Other trials found little. In 60 young women with premenstrual syndrome, 30 mg a day for 12 weeks moved sleep quality scores by -1.48 points within the zinc group, which did not reach significance (P = 0.07). That figure is a change within one group, not a comparison with placebo. In 16 trained men limited to 4 hours of sleep, zinc magnesium aspartate for two nights had no effect on sleep or next-morning performance.

Sleep length

Myth. The idea that zinc makes you sleep longer has no trial support in adults. The 2024 review found two trials that measured sleep duration, including one of 25 mg a day for 12 weeks in people with major depression, and neither saw a significant change. Two trials is a small base, so this is a no-effect finding on thin data.

Zinc mixed with other things

Several positive results come from products where zinc was not alone. In 43 care-home residents with insomnia, a nightly mix of 5 mg melatonin, 225 mg magnesium and 11.25 mg zinc for 8 weeks improved sleep quality scores by 6.8 points more than placebo (95% CI 5.4 to 8.3). Melatonin is in that mix, so the trial cannot say what zinc added. In 120 healthy adults tracked with a wrist monitor for 12 weeks, a zinc-rich oyster food shortened the time to fall asleep and improved sleep efficiency against placebo. Oysters carry far more than zinc, and the abstract gives no doses or effect sizes.

Two larger meta-analyses of sleep supplements do not isolate zinc. A 2025 analysis of 28 trials found all the supplements together lowered sleep quality scores by 0.70 points, a small gain (95% CI -1.37 to -0.03), and named zinc among those that may help, with no separate estimate. A 2022 analysis of 31 trials could not pool zinc at all and said more research is needed. A 2025 meta-analysis of 5 trials in young women with premenstrual syndrome found zinc lowered several symptoms, insomnia among them, but there insomnia is one item on a premenstrual questionnaire, and the abstract gives no size for it.

Blood zinc and sleep in observational data

People with more zinc in their blood tend to report better sleep. In 3660 US adults, higher serum zinc came with 30% lower odds of a self-reported sleep disorder. In a Chinese cohort of 1295 children, lower blood zinc at age 3 to 5 predicted poorer sleep quality and efficiency at 11 to 15. In 5067 US adults, zinc was not linked to short sleep. These are associations. Poor sleep, illness or diet could drive both the zinc level and the sleep.

Who should be careful

Not for everyone. The doses behind the positive trials are close to the safety limit. The NIH Office of Dietary Supplements sets the upper limit for adults at 40 mg a day, and 4 to 34 mg for children depending on age. It warns that 50 mg or more for weeks can block copper absorption, weaken immune function and lower HDL cholesterol.

Zinc interacts with some medicines. The NIH Office of Dietary Supplements names quinolone and tetracycline antibiotics and penicillamine. If you take any of those, the timing of a zinc supplement is a question for your pharmacist. Apart from the upper limits by age, we have no card on zinc supplements for sleep in pregnancy or in children, so this page says nothing about those groups.

What expert bodies say

No expert body we searched has a position on zinc for sleep. The NIH Office of Dietary Supplements fact sheet covers limits, excess and interactions, and has no passage on sleep.

How we searched

What would change this answer

• A placebo-controlled trial of zinc alone at or below the 40 mg upper limit, with sleep measured by a wrist monitor or a sleep lab and not only by questionnaire. We found no such trial registered.
• A meta-analysis that pools zinc-only trials and reports an effect size.
• Trials that check zinc status at the start, to see whether any benefit is limited to people who are short of zinc.

Sources

1. ev-zns-01 · Meta-analysis or systematic review · systematic review of randomized controlled trials · n = 8 studies (9 arms)
   Similarly, Haddadian‐Khouzani et al. found that supplementation with 30 mg of zinc gluconate in dialysis patients for 12 weeks significantly improved sleep quality compared to the placebo.
   
   Who: randomized trials of zinc supplementation and sleep in adults, older adults, dialysis patients, ICU nurses, children and infants
   Effect: PSQI improved: older adults 30 mg/d 10 wk; dialysis 30 mg/d 12 wk; ICU nurses 220 mg zinc sulfate every 72 h. No change: PMS 30 mg/d 12 wk; ME/CFS melatonin 10 mg + zinc 10 mg 16 wk. No meta-analysis
   Certainty: No pool; 5 of 8 studies are from Iran; populations and doses vary widely.
   Health Science Reports, 2024, 7(10):e70019 (Jazinaki et al.) · checked 2026-10-07 · we read the fulltext
2. ev-zns-02 · Meta-analysis or systematic review · systematic review of randomized controlled trials · n = 2 trials
   Similarly, Ranjbar et al. conducted a study on patients with major depression and found that receiving 25 mg of zinc supplement daily for 12 weeks did not lead to a significant change in sleep duration compared to the control group.
   
   Who: adults in randomized trials of zinc (ICU nurses; patients with major depression)
   Effect: no significant change in sleep duration vs control
   Certainty: Two studies; sleep is a secondary endpoint.
   Health Science Reports, 2024, 7(10):e70019 (Jazinaki et al.) · checked 2026-10-07 · we read the fulltext
3. ev-zns-03 · Meta-analysis or systematic review · systematic review of randomized controlled trials · n = 8 studies
   Furthermore, the majority of studies that have investigated the effects of zinc supplementation at doses exceeding 30 mg/day over 12 weeks or more in adult populations reported a significant improvement in sleep quality.
   
   Who: randomized trials of zinc supplementation and sleep
   Effect: benefit reported mostly at > 30 mg/day for >= 12 weeks in adults; larger trials needed
   Certainty: The authors' conclusion; doses above 30 mg approach the upper limit of 40 mg.
   Health Science Reports, 2024, 7(10):e70019 (Jazinaki et al.) · checked 2026-10-07 · we read the fulltext
4. ev-zns-04 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = 5 studies
   Significant decreases were found for insomnia (p < 0.00001), hypersomnia (p = 0.006), feeling overwhelmed (p = 0.05), and overeating (p = 0.0003).
   
   Who: young females with premenstrual syndrome in RCTs of zinc supplementation
   Effect: significant decreases in insomnia (p < 0.00001) and hypersomnia (p = 0.006) PSST sub-scores; physical symptoms MD -0.79 (95% CI -1.39 to -0.20)
   Certainty: Insomnia as a subscale of the PMS questionnaire, not a sleep measurement; the magnitude for insomnia is not given in the abstract.
   Eur J Obstet Gynecol Reprod Biol, 2025 · checked 2026-10-07 · we read the abstract
5. ev-zns-05 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = 28 RCTs
   These findings suggest that tryptophan, vitamin D, omega-3, zinc, and antioxidants may enhance sleep quality by decreasing SL, and WASO increases SE and extends TST, respectively.
   
   Who: people with sleep disorders and healthy individuals in RCTs of dietary supplements
   Effect: all supplements pooled: PSQI MD -0.70 (95% CI -1.37 to -0.03); sleep latency SMD -0.24 (-0.37 to -0.10)
   Certainty: The pool mixes different supplements; there is no separate assessment for zinc.
   Nutrients, 2025 · checked 2026-10-07 · we read the abstract
6. ev-zns-06 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = 31 RCTs
   Further research on the effect of magnesium, zinc, resveratrol and nitrate supplementation on improving sleep quality is required.
   
   Who: randomized controlled trials of dietary supplements on subjective sleep quality, to August 2020
   Effect: amino acids, melatonin and vitamin D improved PSQI; zinc not meta-analyzed
   Certainty: Zinc only descriptively.
   Postgrad Med J, 2022 · checked 2026-10-07 · we read the abstract
7. ev-zns-07 · Randomized controlled trial(s) · double-blind randomized controlled trial · n = 54 (27 vs 26 analyzed)
   The total PSQI, subjective SQ, and sleep latency scores for the intervention group were significantly lower than the control group, which means that the SQ of ICU nurses in the intervention group improved from baseline.
   
   Who: intensive care unit nurses; 220 mg zinc sulfate capsules every 72 hours vs placebo for 1 month
   Effect: lower total PSQI, subjective sleep quality and sleep latency scores than control; serum zinc higher
   Certainty: No PSQI numbers in the abstract; review 39377022 lists the dose as ≈73 mg zinc sulfate per day, not elemental zinc, so it cannot be compared directly with the 40 mg upper limit.
   Workplace Health Saf, 2018 · checked 2026-10-07 · we read the abstract
8. ev-zns-08 · Randomized controlled trial(s) · randomized double-blind placebo-controlled trial · n = 60
   Sleep quality was marginally improved just in the zinc group (- 1.48 ± 4.12, P = 0.07).
   
   Who: young university women with premenstrual syndrome; 30 mg/day elemental zinc or placebo for three months
   Effect: PSQI -1.48 +/- 4.12 within zinc group, P = 0.07
   Certainty: Change within the group; there is no between-group comparison for sleep.
   Arch Gynecol Obstet, 2020 · checked 2026-10-07 · we read the abstract
9. ev-zns-09 · Randomized controlled trial(s) · randomized double-blind placebo-controlled parallel trial · n = 120
   Compared with the placebo group, the zinc-rich food group efficiently decreased the time necessary to fall asleep and improved sleep efficiency, whereas the group that ingested zinc-enriched yeast and astaxanthin oil significantly improved the sleep onset latency.
   
   Who: healthy subjects; placebo, zinc-rich food (oysters), zinc- and astaxanthin-rich food, or zinc-enriched yeast plus astaxanthin oil, 12 weeks
   Effect: zinc-rich food: shorter sleep onset latency and better sleep efficiency vs placebo; zinc yeast + astaxanthin: shorter sleep onset latency
   Certainty: No effect numbers or zinc doses in the abstract; food matrix with other substances.
   Mol Nutr Food Res, 2017 · checked 2026-10-07 · we read the abstract
10. ev-zns-10 · Randomized controlled trial(s) · double-blind randomized counterbalanced crossover trial · n = 16
    Conclusion: Supplementation of ZMA for two nights of partial sleep deprivation had no effect on sleep or subsequent morning performance.
    
    Who: trained males under two nights of partial sleep deprivation (4 h); ZMA, placebo or no pill
    Effect: no effect on sleep, fatigue ratings or submaximal weightlifting
    Certainty: Zinc in combination with magnesium; very short.
    Nutrients, 2024 · checked 2026-10-07 · we read the abstract
11. ev-zns-11 · Randomized controlled trial(s) · double-blind placebo-controlled clinical trial · n = 43
    The food supplement resulted in considerably better overall PSQI scores than placebo (difference between groups in change from baseline PSQI score=6.8; 95% confidence interval=5.4-8.3, P<.001).
    
    Who: long-term care facility residents with primary insomnia, mean age 78; 5 mg melatonin, 225 mg magnesium and 11.25 mg zinc in pear pulp, 1 h before bed
    Effect: difference in PSQI change 6.8 (95% CI 5.4 to 8.3), P < .001; total sleep time improved
    Certainty: Combination with melatonin: the contribution of zinc cannot be isolated.
    J Am Geriatr Soc, 2011 · checked 2026-10-07 · we read the abstract
12. ev-zns-12 · Observational data · prospective cohort with cross-sectional analyses · n = 1295
    Longitudinal analyses indicated that blood zinc concentrations at preschool age predict poor sleep efficiency (OR = 0.186, p = 0.000) and poor sleep quality (OR = 0.358, p = 0.020) in adolescence.
    
    Who: children of the Jintan Child Cohort, blood zinc at 3-5 years and sleep at 11-15 years
    Effect: per log-unit higher zinc: poor sleep efficiency OR 0.186, poor sleep quality OR 0.358 (adolescence)
    Certainty: Association; no confidence intervals in the abstract.
    Nutrients, 2015 · checked 2026-10-07 · we read the abstract
13. ev-zns-13 · Observational data · cross-sectional analysis · n = 3660
    Logistic regression demonstrated that higher serum Zn (OR: 0.70, 95 % CI: 0.51-0.97, p = 0.035), Zn/Cu (OR: 0.62, 95 % CI: 0.45-0.87, p = 0.007), and Zn/Se (OR: 0.68, 95 % CI: 0.49-0.95, p = 0.025) were related to a decreased likelihood of self-reported sleep disorders, and dose-response relationships were detected by the RCS models, after adjustment for sociodemographic, behavioral, and health characteristics.
    
    Who: adults aged 18 or older, NHANES 2011-2016
    Effect: serum zinc OR 0.70 (95% CI 0.51 to 0.97) for self-reported sleep disorders
    Certainty: Cross-sectional; reverse causality is possible.
    J Affect Disord, 2023 · checked 2026-10-07 · we read the abstract
14. ev-zns-14 · Observational data · cross-sectional analysis · n = 5067
    No significant association was found between serum zinc, copper concentrations and the zinc/copper ratio and short sleep duration.
    
    Who: general adults, NHANES 2011-2016
    Effect: long sleep, highest vs lowest serum zinc quartile OR 0.61 (95% CI 0.39 to 0.96); no association with short sleep
    Certainty: Cross-sectional, self-reported sleep duration.
    Biol Trace Elem Res, 2022 · checked 2026-10-07 · we read the abstract
15. ev-zns-15 · Position of an expert body · government fact sheet · n = —
    The Tolerable Upper Intake Level for zinc is 40 mg for adults, and it ranges from 4 to 34 mg for infants, children, and adolescents, depending on age.
    
    Who: healthy adults, infants, children and adolescents
    Effect: UL 40 mg/day adults; 4-34 mg/day by age
    Certainty: Several sleep RCTs used doses near or above this limit.
    NIH Office of Dietary Supplements, Zinc fact sheet for health professionals · checked 2026-10-07 · we read the section
16. ev-zns-16 · Position of an expert body · government fact sheet · n = —
    Doses of 50 mg of zinc or more over a period of weeks can inhibit copper absorption, reduce immune function, and lower high-density lipoprotein cholesterol levels; however, it is unlikely that a person would obtain this much zinc from food alone.
    
    Who: people taking high-dose zinc supplements
    Effect: >= 50 mg/day for weeks: lower copper absorption, immune function and HDL
    Certainty: Authority position.
    NIH Office of Dietary Supplements, Zinc fact sheet for health professionals · checked 2026-10-07 · we read the section
17. ev-zns-17 · Position of an expert body · government fact sheet · n = —
    Zinc may interact with certain medications, such as quinolone antibiotics, tetracycline antibiotics, and penicillamine.
    
    Who: people on regular medications
    Effect: interactions: quinolones, tetracyclines, penicillamine; some diuretics raise zinc loss
    Certainty: A list of examples, not complete.
    NIH Office of Dietary Supplements, Zinc fact sheet for health professionals · checked 2026-10-07 · we read the section