The average adult gets 1.5 to 2 hours of REM sleep per night. Research consistently shows that most people fall short of this, and that the cognitive and emotional costs of REM deprivation compound over time. The good news is that several highly effective interventions exist. The challenge is that most sleep advice conflates REM sleep with general sleep quality, or focuses on supplements before addressing the more impactful behavioral and environmental factors.
This guide addresses REM sleep specifically. The methods below are ranked by evidence strength and realistic impact. Start at the top and work down. Each change compounds the others.
Before you start: Establish a baseline. Track your REM percentage for 2 weeks using a wearable device before making any changes. Apple Watch, Fitbit, Oura Ring, and Garmin all measure sleep stages. Your baseline tells you which methods are working.
1. Cool Your Sleep Surface to 65-68°F
Impact: Very High. Ease: Requires investment for full effect.
Temperature is the single most controllable variable affecting REM sleep duration, and it is the one most people overlook. During REM, your body loses its ability to thermoregulate — you cannot shiver or sweat to adjust your temperature the way you can while awake or in other sleep stages. This means the surrounding temperature becomes the primary thermal input during REM, and an overly warm sleep environment directly cuts REM cycles short.
Research from the NIH and multiple sleep science institutions identifies 65 to 68 degrees Fahrenheit as the optimal sleep temperature range for both REM and deep sleep. Many people sleep in environments significantly warmer than this, particularly in summer or in regions without air conditioning.
Your Temperature Options
Effective but expensive to run all night. Most impactful for people who currently sleep above 70°F.
Improves air circulation and surface cooling. Noise may disrupt sleep for sensitive sleepers.
Removing heavy comforters in warmer months reduces heat trapping. Not effective for people whose mattress itself retains heat.
Circulates temperature-controlled water through the mattress pad all night. Maintains 65-68°F regardless of room temperature. The most precise and effective solution available.
The Good Sleep System is an active water-cooled mattress topper that maintains 65-68°F all night without a subscription or credit check.
Shop Good Sleep System Affiliate link2. Maintain a Consistent Wake Time
Impact: Very High. Ease: Free and immediate.
REM sleep timing is controlled by your circadian clock, not just by how long you have been asleep. Your circadian rhythm determines when each stage of sleep is biologically scheduled. REM is programmed to dominate the final hours before your habitual wake time. When you have a consistent wake time, your brain knows when to begin scheduling those long final REM cycles. When your wake time shifts, your REM window shifts with it and often compresses.
A consistent wake time is the highest-leverage free intervention for REM sleep. More than bedtime, more than sleep duration, your wake time anchors your entire sleep architecture. Keep it consistent to within 30 minutes every day, including weekends. If you need to recover from a late night, go to bed later and keep the wake time the same rather than sleeping in.
The weekend trap: Sleeping in on weekends feels restorative but it shifts your circadian phase later, which is why Sunday nights are often difficult and Monday mornings feel especially rough. This is sometimes called "social jet lag" and it measurably reduces REM quality across the week.
3. Stop Alcohol at Least 3 Hours Before Bed
Impact: Very High for drinkers. Ease: Behavioral only.
Alcohol is the most common and most underestimated REM suppressant. The mechanism is well-established: alcohol increases adenosine levels in the brain, which promotes sleep onset and increases slow-wave sleep in the first half of the night. This is why people often report sleeping deeply after drinking. However, as alcohol metabolizes in the second half of the night, it fragments sleep architecture and suppresses REM. The result is a first half that feels deep and a second half that is fragmented and light.
Research shows that even 1 to 2 standard drinks consumed within 3 to 4 hours of bedtime reduce first-half REM by 20 to 40 percent. Heavier consumption produces more severe and longer-lasting suppression. The morning grogginess many people attribute to "sleeping too much" after drinking is in many cases a symptom of REM deprivation.
The practical target is stopping alcohol consumption at least 3 hours before sleep. For most people, this means no alcohol after 7pm if they sleep at 10pm. The further before sleep the last drink occurs, the less REM suppression results.
4. Use Evidence-Based Sleep Supplements
Impact: Moderate to High depending on individual. Ease: Simple.
Supplements are most effective when the behavioral and environmental factors above are already addressed. They are not a substitute for consistent sleep timing, appropriate temperature, or eliminating alcohol. With that foundation in place, several compounds have meaningful evidence supporting their role in sleep quality and REM duration.
Magnesium Glycinate
200-400mg, 60 min before bedMagnesium supports GABA activity and reduces the muscular tension and nervous system activation that prevents deep sleep and disrupts REM. Glycinate is the most bioavailable form with the fewest gastrointestinal side effects. Start at 200mg and increase to 400mg if needed.
L-Theanine
100-200mg, 30-60 min before bedAn amino acid found naturally in tea leaves that promotes alpha brain wave activity without causing sedation. Reduces the mental chatter and low-level anxiety that delays sleep onset and fragments early sleep cycles. Can be combined with magnesium glycinate effectively.
Melatonin (Low Dose)
0.5-1mg, 60-90 min before bedLow-dose melatonin helps regulate circadian timing, particularly useful for shift workers, frequent travelers, or people with irregular schedules. Higher doses (5-10mg common in many products) do not produce stronger sleep effects and may suppress natural melatonin production over time. Use the lowest effective dose.
Glycine
3g, 30 min before bedAn amino acid that lowers core body temperature and may improve sleep quality and REM duration. A 2012 study in the journal Sleep and Biological Rhythms found that 3g of glycine before bed improved subjective sleep quality and reduced daytime fatigue. Well-tolerated and inexpensive.
Important: Consult a healthcare provider before starting any supplement, particularly if you take medications. SSRIs and other medications interact with several sleep supplements. This is informational content only, not medical advice.
5. Optimize Your Sleep Environment
Impact: High. Ease: Mostly free or low-cost.
Light and noise are the two environmental factors with the strongest evidence for disrupting sleep architecture. Both cause micro-arousals, brief interruptions in sleep that fragment cycles without fully waking you. You will not remember these arousals, but they reduce time spent in REM and deep sleep and are felt the next day as fatigue and poor concentration.
- Darkness: Any light exposure during sleep can suppress melatonin and shift sleep architecture toward lighter stages. Blackout curtains or a sleep mask are the most effective solutions. Streetlights, phone screens left on, and LED indicator lights on electronics all qualify as disruptive.
- Noise masking: Environmental noise causes micro-arousals even when it does not fully wake you. White noise, brown noise, or pink noise played at a consistent moderate volume masks variable sounds effectively. A fan, air purifier, or dedicated white noise device all work.
- Light before bed: Bright light, especially blue-spectrum light from screens, suppresses melatonin production and delays circadian sleep timing. Dim lights after 9pm, use blue-light blocking glasses if screen use continues, and reduce screen brightness to minimum in the final hour before bed.
6. Reduce Pre-Sleep Cortisol
Impact: High for stressed individuals. Ease: Behavioral.
Cortisol, the primary stress hormone, is directly antagonistic to the neurological state required for REM sleep. Elevated cortisol at bedtime delays sleep onset, reduces REM duration, and increases the frequency of nighttime arousals. For people who identify as stressed or anxious, this is one of the highest-leverage targets.
A structured wind-down routine is the most evidence-backed intervention for reducing pre-sleep cortisol. The content matters less than the consistency. Anything that reliably signals to your nervous system that the day is complete and demands are suspended helps lower cortisol. Common effective approaches include reading fiction, gentle stretching or yoga, a warm shower taken 1 to 2 hours before bed (the subsequent body temperature drop promotes sleep onset), and avoiding work emails or news in the final hour before sleep.
A warm shower or bath 1 to 2 hours before bed is worth highlighting specifically. The subsequent drop in core body temperature after leaving the warm water mimics the natural temperature drop that initiates sleep and has been shown in multiple studies to improve both sleep onset speed and REM quality.
7. Track Your REM Sleep to Measure Progress
Impact: Indirect but essential for optimization. Ease: Requires a wearable.
You cannot optimize what you cannot measure. Implementing changes without tracking their effect means you have no feedback loop and no way to know which interventions are working for your specific physiology.
Consumer wearables including Apple Watch Series 6 and later, Fitbit devices, Oura Ring, and Garmin sleep tracking all estimate sleep stages with meaningful accuracy. They are not equivalent to polysomnography conducted in a sleep laboratory, but research comparing consumer wearable data to PSG shows sufficient accuracy for tracking trends over time.
The protocol is straightforward: record your baseline REM percentage for 2 weeks before making any changes. Then implement one change at a time and track for 2 weeks. This reveals which interventions produce the most impact for your specific physiology and sleep environment. Temperature changes and alcohol elimination typically produce visible changes in wearable data within 3 to 5 nights.
Additional Methods Worth Implementing
Exercise Regularly, But Not Late
Regular aerobic exercise significantly increases slow-wave sleep and indirectly supports REM by improving overall sleep architecture. Avoid vigorous exercise within 2 to 3 hours of bedtime as it elevates cortisol and core body temperature, both of which delay sleep onset.
Protect Your Final 2 Hours of Sleep
Because REM cycles grow longer across the night and concentrate in the final hours before waking, the last 2 hours of an 8-hour night contain the majority of your total REM time. Cutting sleep short by 90 minutes can eliminate nearly half of your REM. If you must sleep fewer hours, go to bed later rather than waking earlier.
Address Sleep Apnea If Relevant
Obstructive sleep apnea causes repeated micro-arousals throughout the night and is one of the most common causes of poor sleep architecture. If you snore heavily, wake frequently, or feel exhausted despite sufficient time in bed, a sleep study is warranted. CPAP treatment typically restores near-normal sleep architecture within weeks.
Limit Caffeine After Noon
Caffeine has a half-life of 5 to 7 hours in most adults. Coffee consumed at 3pm still has half its caffeine active at 8pm and a quarter active at midnight. Caffeine does not suppress REM directly but delays sleep onset and reduces total sleep time, which reduces total REM time as a consequence.
Consider Your Medications
Several commonly prescribed medications suppress REM sleep, including SSRIs, SNRIs, MAOIs, and benzodiazepines. If you are taking these and experiencing poor sleep quality despite good sleep hygiene, discuss sleep architecture with your prescribing physician. Never modify medications without medical supervision.
Where to Start: Priority Order
If you implement all 12 methods simultaneously you will have no feedback loop. Start with the highest-impact changes in this order.
For temperature specifically, the Good Sleep System is the most effective single tool for maintaining 65-68°F all night.
Shop Good Sleep System Affiliate link