REM sleep increases naturally in the later cycles of the night, so the single most effective way to get more of it is to sleep longer. Your first REM period lasts only about 10 minutes, but each subsequent one grows longer, with the final cycles lasting up to an hour. If you’re cutting your night short by even 60 to 90 minutes, you’re disproportionately losing REM sleep. Beyond simply sleeping more, several specific habits, substances, and environmental factors can either protect or erode the REM sleep you do get.
Why REM Sleep Matters
REM sleep is when your brain processes emotional experiences and locks in certain types of memories. During this stage, your brain reactivates emotional events from the day but does so in a neurochemical environment that’s calmer than waking life. The result is that you retain the content of emotional experiences while the raw intensity of the feeling fades. This is one reason a difficult situation can feel more manageable after a full night of sleep.
REM sleep also strengthens retention of emotionally significant information over neutral information. Studies measuring brain activity show heightened electrical responses over the frontal cortex when people recognize emotional material after REM-rich sleep compared to other sleep stages. In practical terms, skimping on REM doesn’t just leave you groggy. It can leave you more emotionally reactive and less able to consolidate what you learned the day before.
How REM Cycles Work Through the Night
A full sleep cycle takes roughly 80 to 120 minutes and repeats four to six times per night. Each cycle contains lighter sleep, deeper sleep, and a REM period, but the proportion shifts as the night goes on. Early cycles are heavy on deep sleep and light on REM. Later cycles flip that ratio, with REM periods growing progressively longer.
This back-loading is why sleeping seven hours instead of eight doesn’t just cost you one hour of mixed sleep. It specifically costs you a long REM period that would have occurred in that final cycle. If you consistently wake up early or go to bed late, you may be getting adequate deep sleep while chronically shortchanging your REM time.
Keep Your Bedroom Cool
Room temperature has a direct effect on REM stability. The recommended range for adults is 60 to 67°F (about 15 to 19°C). Temperatures in this range help facilitate and stabilize REM sleep, while a room that’s too warm can cause more awakenings during the lighter, REM-heavy second half of the night. If you tend to sleep hot, consider lighter bedding or a fan rather than just lowering the thermostat.
Use Morning Light to Set Your Clock
Your body’s internal clock determines when REM-heavy sleep periods occur, and bright light is the strongest signal that sets it. Morning light exposure, particularly within an hour of your usual wake time, shifts your circadian rhythm earlier, making you sleepy earlier in the evening and more likely to get a full night of sleep. Researchers estimate that properly timed morning light can shift your sleep schedule by about one hour per day.
Bright light during midday also improves daytime alertness and nighttime sleep quality. If you work indoors, even a short walk outside in the morning can make a meaningful difference. The flip side matters too: bright light in the evening pushes your clock later, delaying sleep onset and compressing the REM-rich final hours of the night.
Alcohol Suppresses REM in the First Half of the Night
Alcohol is one of the most common and underappreciated REM disruptors. It acts as a sedative that suppresses REM sleep in a dose-dependent way during the first half of the night. As your body metabolizes the alcohol, REM can rebound in the second half, but this rebound sleep is often fragmented and lighter than normal. The net effect is less total REM and lower quality REM.
Even moderate drinking in the evening can produce this pattern. The closer to bedtime you drink, and the more you consume, the greater the suppression. If you’re specifically trying to increase REM sleep, reducing or eliminating evening alcohol is one of the highest-impact changes you can make.
Medications That Reduce REM Sleep
Several widely prescribed medications suppress REM sleep as a side effect. The most common culprits are antidepressants: SSRIs (like sertraline and fluoxetine), SNRIs (like venlafaxine), and older tricyclic antidepressants all reduce time spent in REM. This effect is significant enough that sleep clinics ask patients to stop these medications at least two weeks before certain diagnostic sleep tests, though most patients don’t manage to do so.
If you take one of these medications and suspect your REM sleep is suffering, that’s a conversation worth having with your prescriber. The benefit of the medication may well outweigh the REM reduction, but alternatives or timing adjustments sometimes help.
Sleep Apnea and REM Fragmentation
Obstructive sleep apnea tends to be worse during REM sleep than during other stages. During REM, your body naturally relaxes your skeletal muscles more deeply, including the muscles that keep your upper airway open. For people with sleep apnea, this means more frequent breathing pauses and more awakenings during the exact stages where REM sleep should be peaking. The resulting fragmentation can significantly reduce total REM time.
If you snore heavily, wake up gasping, or feel persistently unrefreshed despite getting enough hours of sleep, untreated sleep apnea could be the reason your REM sleep is low. Treating it often produces a noticeable rebound in REM sleep and dream recall.
Consistent Sleep Timing
Going to bed and waking up at roughly the same time each day reinforces your circadian rhythm, which in turn optimizes the timing of your sleep stages. When your schedule is erratic, your body may not reliably produce the long REM periods that normally occur in the early morning hours. Weekend sleep schedule shifts of two or more hours can be enough to disrupt this pattern.
Consistency also helps you fall asleep faster, which means less time spent trying to sleep and more time in actual sleep cycles. A predictable schedule combined with morning light exposure gives your circadian system clear, reinforcing signals that keep REM periods occurring at their natural times and durations.
Prioritize Total Sleep Time
Most of the strategies above work by removing barriers to REM sleep. But the foundation is simple math: you need enough total sleep for four to six full cycles, and the REM payoff comes disproportionately from the last one or two. For most adults, that means aiming for seven to nine hours. If you’re currently sleeping six hours and wondering why your REM numbers on a sleep tracker look low, the answer is probably not a supplement or a hack. It’s the missing cycles at the end of the night where your longest REM periods would have occurred.