The review, which analyzed 12 placebo-controlled trials, found that while magnesium may provide modest benefits for sleep in certain populations, the current evidence does not support its use as a routine treatment for insomnia.
Despite these findings, lead author Adrian Lopresti, managing director at Clinical Research Australia, said magnesium may genuinely help some people, including those with inadequate magnesium intake or particular sleep difficulties, and further research is therefore needed to distinguish between these groups.
“Our review doesn’t establish that magnesium is ineffective,” he said. “Rather, the available clinical evidence is inconsistent, and we cannot yet confidently recommend it as a routine treatment for insomnia.
“Having said that, I must admit that, anecdotally and from my own clinical experience, magnesium does appear to help many people with their sleep. I don’t think we should dismiss these experiences, but we need to recognize that clinical observations and personal experiences are not the same as evidence from well-controlled trials.”
The magnesium market
The global magnesium supplements market was valued at $4.7 billion in 2025, according to Custom Market Insights, and is projected to reach nearly $9 billion by 2034, growing at a CAGR of 7.43%.
North America is the largest regional market, with data from market insights firm SPINS showing that magnesium supplement sales reached $336 million in 12 months leading up to June 2024, up by 30% compared to 2022. The same data shows that magnesium emerged as a key sales catalyst in relaxation categories, accounting for 27% of the growth within sleep, calmative and mood supplements.
Individual retailers have also reported increased consumer interest in magnesium. Search data from Holland & Barrett shows that magnesium was the most searched ingredient of 2025, raking in 8.5 million product searches.
Two articles on magnesium also featured in Holland & Barrett’s top-searched articles, with ‘Best forms of magnesium’ ranking first and ‘Benefits of magnesium glycinate’ ranking third. However, magnesium did not feature on the retailer’s best-sellers list.
“Although magnesium doesn’t appear in our overall top 10 sellers, it has seen a significant surge in demand throughout 2025,” said Rachel Chatterton, product director of global brand at Holland & Barrett, commenting on the retailer’s latest trends report.
“We know from our customers that lack of energy, sleep struggles and difficulty relaxing remain some of their biggest well-being concerns—with 72% telling us they don’t have enough energy to get through the day,” she added. “Magnesium has broad appeal because its benefits extend well beyond sleep: Consumers also turn to it for muscle recovery and cramp support, heart health and even PMS symptoms.”
TikTok has played a significant role in fueling this interest, according to Chatterton. Health creators have popularized magnesium on social media, explaining how different forms are associated with for specific health benefits—for example, citrate for gut motility, threonate for brain support and malate for energy.
What form of magnesium is best for sleep?
Magnesium bisglycinate is the most commonly used form of magnesium for sleep, however, in the review, only one study used this form. The remaining studies used magnesium L-threonate (three trials), magnesium oxide (two trials), magnesium chloride (two trials), magnesium gluconate (one trial) and magnesium citrate (one trial). The remaining form was a ‘food grown’ magnesium, which did not specify the elemental status.
Overall, favorable sleep-related findings were reported in individual trials using food grown magnesium, as well as oxide, bisglycinate, threonate and chloride-based preparations. Trials using magnesium citrate did not show consistent sleep benefits.
In terms of limitations, none of the trials directly compared magnesium forms, and interpretation was limited by differences in population, dose, treatment duration, outcome measure and study quality. The authors noted that these comparisons should therefore be considered “descriptive only.”
“Different magnesium formulations can differ in their absorption and bioavailability, so it’s possible that some forms may be more effective than others,” Lopresti said. “However, we currently don’t have sufficient clinical evidence to establish that one formulation is superior for improving sleep.”
One of the major challenges, he added, is that studies sometimes report the total weight of the magnesium compound rather than the amount of elemental magnesium, complicating comparisons between trials.
In addition, studies often have different primary and secondary outcomes. For example, magnesium L-threonate has been shown to improve sleep-related daytime functioning, although improvements in sleep itself have been less consistent.
“This highlights the importance of distinguishing between improvements in how people feel and function during the day and measurable improvements in their sleep,” Lopresti said, adding that future research should investigate individual formulations using clearly defined doses and, ideally, include direct comparisons between different magnesium forms.
Are certain populations more likely to benefit from magnesium supplementation?
Certain populations appear to be more likely to benefit from magnesium supplementation. For example, favorable findings were reported in some trials enrolling older adults with insomnia, adults with self-reported poor sleep and participants with sleep disturbance secondary to nocturnal leg cramps.
In contrast, trials in women with PCOS, adults with fibromyalgia and adults with cognitive impairment did not show clear magnesium-specific sleep benefits. However, findings were inconsistent within and across population groups, and overall, no subgroup showed sufficiently consistent evidence to identify a clearly responsive population.
“One potentially important factor is baseline magnesium intake or status,” Lopresti said. “It’s reasonable to hypothesize that people with inadequate magnesium intake might benefit more from supplementation than those who already consume sufficient amounts. However, very few trials have adequately assessed this.”
For example, one trial of magnesium bisglycinate found modest improvements in insomnia symptoms, with exploratory analyses suggesting potentially greater benefits in people with lower dietary magnesium intake. The findings, however, have yet to be replicated.
There have been some encouraging findings in older adults and people reporting poor sleep, but the results are inconsistent and the studies have generally been relatively small.
Lopresti said future research should therefore focus on deciphering which groups of people are most likely to benefit from magnesium supplementation. This research must take into account baseline magnesium status, pre-existing medical conditions and other factors which might affect the final outcome.
“I suspect magnesium is unlikely to be equally effective for everyone, and future research needs to move beyond asking whether magnesium improves sleep to identifying who might benefit, under what circumstances and by how much,” Lopresti said.
Anecdotes do not establish efficacy, but should not be dismissed
The review also highlighted several notable findings about the quality of the randomized controlled trials. For example, most were judged to have a medium-to-high risk of bias, and sleep quality was often assessed using self-reported measures rather than objective methods.
Some groups also reported non-serious adverse events, including gastrointestinal disturbances, although these were not consistently reported or clearly attributable to magnesium.
Overall, the certainty of evidence was low or very-low for all sleep reported outcomes, the authors reported, with sleep-related impairment of daytime functioning downgraded to very low certainty because of heterogeneous measures, frequent secondary or exploratory status, form-specific findings and inconsistency.
Lopresti said claims about magnesium and sleep from the supplement industry may therefore be overinflated, likely due to brands and suppliers taking promising findings from a small number of studies and generalizing them across different populations, formulations and doses.
Marketing claims should therefore reflect research uncertainty rather than suggesting that magnesium is an established treatment for insomnia, Lopresti added, emphasizing the need to consider that clinical research may be lagging behind real-world experiences.
“Many people report improvements in their sleep when taking magnesium, and while these experiences don’t establish efficacy, I don’t think they should be dismissed,” he said. “It’s possible that magnesium is beneficial for certain individuals or under particular circumstances that haven’t been adequately investigated in clinical trials.
“The key message is that we need to be careful not to overstate the evidence in either direction. Some marketing claims may be ahead of the science, but it’s equally possible that the research has yet to fully capture the benefits that some people are experiencing. Ultimately, we need better-quality studies to help bridge that gap.”
Source: Journal of Dietary Supplements. doi: 10.1080/19390211.2026.2719670. “Magnesium Supplementation for Sleep in Adults: A Systematic Review of Randomized Controlled Trials”. Authors: A. Lopresti, et al.
