Anirva sells Sleep Harmony, a dietary supplement. This article shares research for general education and is not medical advice.
If your tracker shows less REM sleep than you hoped, the honest answer is that REM is hard to change directly — most of what helps is protecting your whole night. Here's what studies and sleep experts suggest, what tends to reduce REM, and what the research says about supplements.
In this article
What Is REM Sleep, and Why Does It Come Late?
REM stands for rapid eye movement. It's the stage when you're most likely to dream, [2] and it makes up about 20% to 25% of the night in healthy adults. [1] The first REM period begins about 90 minutes after you fall asleep and returns about every 90 minutes. REM tends to take over in the second half of the night.
Cleveland Clinic describes REM sleep as helping with memory and emotion processing. [3] We did not find evidence that raising REM with a habit or a supplement improves either — so the goal here is to protect your sleep as a whole.
- REM comes mostly in the second half of the night, so a shorter night likely trims it.
- Alcohol is the clearest REM reducer. In a meta-analysis of 27 studies, even about two standard drinks delayed and reduced REM sleep. [6]
- Exercise helps sleep overall, but meta-analyses found slightly less REM, so it's not a REM strategy. [8][9]
- Evidence for supplements that raise REM is thin and mixed. We did not find one with consistent evidence in healthy adults.
- Trackers estimate REM too. In one study, a smart ring labeled 23% of lab-scored REM as light sleep. [16]
Facts at a Glance
| Fact | Detail |
|---|---|
| REM share of the night | About 20–25% in healthy adults [1] |
| Alcohol's REM effect | ~18 min later start, ~11 min less REM, even at ~2 drinks [6][7] |
| Exercise's REM effect | Slightly less REM (~2–5 min) in meta-analyses [9] |
| Tracker accuracy | One study: 23% of lab-scored REM mislabeled as light sleep [16] |
| Last reviewed | [DATE] |
Protect the Second Half of Your Night
Because REM gets longer toward morning, a short night likely costs REM more than other stages. That fits the AASM and Sleep Research Society advice that adults sleep 7 or more hours a night on a regular basis. [5] It also fits Cleveland Clinic's suggestion to focus on a consistent wake time, since a routine bedtime tends to follow. [3]
Alcohol
Alcohol is often used to wind down, and it's the clearest REM reducer in the research. A 2025 meta-analysis of 27 studies found that even a low dose — about two standard drinks — delayed the start of REM and reduced its duration. [6] The effect grew with the dose. Across the studies, REM began about 18 minutes later on average and lasted about 11 minutes less. [7] Cleveland Clinic notes that alcohol before bed delays REM in the first half of the night and causes more awakenings. [3]
Exercise and Other Habits
Exercise supports sleep in many ways, but REM isn't one of them. A meta-analysis of acute and chronic exercise found more slow-wave sleep and more total sleep time, along with less REM sleep. [8] A later review put the change at about 2 to 5 minutes less REM and a REM start delayed by about 10 minutes. [9] A review of exercise and sleep physiology reached a similar conclusion. [10] That's a small change next to the 85 to 120 minutes of REM in a typical night, so it's no reason to skip exercise.
Cleveland Clinic's sleep specialists also suggest a consistent schedule, a cool, dark, quiet bedroom, a wind-down routine, less stress, and limiting caffeine and nicotine. [3] These help sleep in general — we did not find trials showing they raise REM specifically. Cleveland Clinic also notes that many medicines can affect sleep. If you notice sleep changes after starting a medicine, tell your provider, and don't stop it on your own. If you suspect a sleep disorder, a provider can order a sleep study.
Supplements for REM Sleep
We did not find a supplement with consistent evidence that it raises REM sleep in healthy adults. Here's what the studies we found show.
Magnesium L-threonate had two wearable trials that disagree. One trial found a higher REM sleep score on a ring than placebo, [11] and a larger trial found no group differences in ring-based sleep outcomes. [12] Cleveland Clinic notes that research on magnesium and sleep is limited. [4]
In a 2026 trial of 2 mg sustained-release melatonin in 59 adults, REM duration rose by about 2 minutes, while it fell by about 16 minutes with placebo. [13] The trial was funded by the product's maker.
One small crossover trial of 50 mg of 5-HTP reported a higher share of REM sleep. [14] It included 18 people who had a REM-related sleep disorder and was described by its authors as preliminary, so it doesn't tell us about typical sleepers. 5-HTP can interact with antidepressants. [15]
Worth knowing: For reference, each serving of Sleep Harmony contains 5 mg of melatonin, 50 mg of 5-HTP and 50 mg of magnesium as glycinate. The studies above used different amounts and forms, so their results may not apply to it. We do not claim that Sleep Harmony increases REM sleep, and the finished formula has not been clinically tested.
What About Your Tracker?
Trackers estimate REM as well. In a study of 96 adults, a smart ring labeled 23% of lab-scored REM sleep as light sleep. [16] A tracker's REM number is best read as a rough guide, and a trend over weeks says more than one night. Our article on how much deep sleep and REM sleep adults get covers typical ranges.
The Habits at a Glance
| Habit or Factor | What the Research Shows for REM | Note |
|---|---|---|
| Enough total sleep | REM tends to be longer in the second half of the night | Advice is 7+ hours for adults [5] |
| Alcohol | Delays and reduces REM, more with larger doses | Clearest effect in the research [6] |
| Exercise | Slightly less REM in meta-analyses | Still supports sleep overall [9] |
| Schedule, room, routine | No REM-specific trials found | Suggested for sleep in general [3] |
| Medicines | Many can affect sleep | Tell your provider; don't stop on your own |
| Supplements | Thin and mixed evidence | See the supplements section |
If you snore loudly, wake up gasping or feel very sleepy in the day, a healthcare provider can check for sleep disorders such as sleep apnea. Melatonin's most common effect is daytime drowsiness. Mount Sinai's health library cautions against 5-HTP for people who take antidepressants unless a provider supervises, and for women who are pregnant or breastfeeding. [15] If you are pregnant, nursing, take prescription medicines or have a health condition, check with your healthcare provider first.
If You'd Like to Start Small
If you'd like to start with one thing, sleep specialists suggest a consistent wake time and enough hours for a full night. Keeping alcohol away from bedtime is the change with the clearest link to REM. A sleep diary of a few weeks, noting when you slept and how rested you felt, can show whether a change is helping.
One formula, amounts you can compare
Each serving of Sleep Harmony contains 5 mg of melatonin, 50 mg of 5-HTP and 50 mg of magnesium as glycinate. The studies discussed above used different amounts and forms, so their results may not apply directly. We do not claim that Sleep Harmony increases REM sleep, and the finished formula has not been clinically tested.
See the Sleep Harmony product page →The Short Version
REM is hard to change directly, and the most reliable steps are protecting your total sleep and being careful with alcohol near bedtime. Exercise supports sleep overall, though it slightly lowers REM. No supplement had consistent evidence of raising it, and trackers only estimate REM, so how rested you feel is a helpful check.
Frequently Asked Questions
How can I increase REM sleep?
Why am I getting so little REM sleep?
Does alcohol affect REM sleep?
Do supplements increase REM sleep?
Does exercise increase REM sleep?
How much REM sleep is normal?
References
- Medscape Reference. Normal sleep, sleep physiology, and sleep deprivation: normal sleep in adults, infants, and the elderly.
- Texas Health Resources. How much deep, light and REM sleep do you need?
- Cleveland Clinic. Here's how to get more deep sleep and REM sleep. May 9, 2025.
- Cleveland Clinic. Does magnesium help you sleep better? September 4, 2026.
- Watson NF, Badr MS, Belenky G, et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. J Clin Sleep Med. 2015;11(6):591–592. doi:10.5664/jcsm.4758.
- Gardiner C, Weakley J, Burke LM, Roach GD, Sargent C, Maniar N, et al. The effect of alcohol on subsequent sleep in healthy adults: a systematic review and meta-analysis. Sleep Med Rev. 2025;80:102030. PMID 39631226; doi:10.1016/j.smrv.2024.102030.
- Sleep Wake Advisor. Alcohol consumption impairs REM sleep. (Summary of Gardiner 2025, with the average REM changes.)
- Kubitz KA, Landers DM, Petruzzello SJ, Han M. The effects of acute and chronic exercise on sleep: a meta-analytic review. Sports Med. 1996;21(4):277–291. doi:10.2165/00007256-199621040-00004.
- Driver HS, Taylor SR. Exercise and sleep. Sleep Med Rev. 2000;4(4):387–402. doi:10.1053/smrv.2000.0110.
- Uchida S, Shioda K, Morita Y, Kubota C, Ganeko M, Takeda N. Exercise effects on sleep physiology. Front Neurol. 2012;3:48. doi:10.3389/fneur.2012.00048.
- Hausenblas HA, Lynch T, Hooper S, Shrestha A, Rosendale D, Gu J. Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: a randomized controlled trial. Sleep Med X. 2024;8:100121. (Corrigendum: Sleep Med X. 2025;9:100141.) PMID 39252819; doi:10.1016/j.sleepx.2024.100121.
- The effects of magnesium L-threonate (Magtein) on cognitive performance and sleep quality in adults: a randomised, double-blind, placebo-controlled trial. Front Nutr. 2025. doi:10.3389/fnut.2025.1729164.
- Thanawala S, Shah R, Lopes A, Kulkarni M, Jain B, Andhalkar N. Efficacy and safety of sustained-release melatonin capsules (2 mg) in healthy adults with poor sleep quality: a randomized, double-blind, placebo-controlled trial. Clocks Sleep. 2026;8(2):31. (Funded by the product's maker.) doi:10.3390/clockssleep8020031.
- Preliminary finding of a randomized, double-blind, placebo-controlled, crossover study to evaluate the safety and efficacy of 5-hydroxytryptophan on REM sleep behavior disorder in Parkinson's disease. Sleep Breath. PMC9418091; doi:10.1007/s11325-021-02417-w.
- Mount Sinai Health Library. 5-Hydroxytryptophan (5-HTP).
- Svensson T, Madhawa K, Nt H, et al. Validity and reliability of the Oura Ring Generation 3 (Gen3) with Oura sleep staging algorithm 2.0 (OSSA 2.0) when compared to multi-night ambulatory polysomnography: a validation study of 96 participants and 421,045 epochs. Sleep Med. 2024;115:251–263.
