The most effective way to get more REM sleep is simply to sleep longer. REM periods grow longer as the night progresses, with the earliest lasting just a few minutes and the final ones stretching up to 30 minutes. Most of your REM sleep is packed into the last couple hours of the night, so cutting sleep short by even 30 to 60 minutes can disproportionately slash your REM time.
Beyond total sleep time, several controllable factors influence how much REM sleep you actually get and how stable those REM periods are. Here’s what to focus on.
Why the Last Hours of Sleep Matter Most
Sleep cycles through stages in roughly 90-minute loops. Each loop contains a period of REM sleep, but these periods are not equal. Your first REM episode of the night may last only a few minutes. With each subsequent cycle, the REM portion grows. By the final cycle of a full night’s sleep, you can spend up to half an hour in continuous REM.
This back-loading means that someone sleeping six hours instead of eight isn’t just losing 25% of their sleep. They’re losing a far larger share of their REM sleep, because those last two hours contain the longest, most REM-dense cycles. If you’re consistently waking up to an alarm after six or seven hours, extending your sleep is the single highest-impact change you can make.
Keep Your Bedroom Cool
Room temperature directly affects REM stability. The recommended range for adults is 60 to 67°F (15 to 19°C). Temperatures in this window help facilitate stable REM sleep, while a room that’s too warm tends to fragment it. Your body naturally drops its core temperature during sleep, and a cool room supports that process rather than fighting it. If you tend to sleep hot, lighter bedding or a fan can help you stay in this range without feeling cold when you first get into bed.
Alcohol Disrupts REM Even in Small Amounts
Alcohol is one of the most common and least recognized REM suppressors. It may help you fall asleep faster, but it significantly reduces the amount of REM sleep you get, particularly in the second half of the night. As your body metabolizes alcohol during sleep, it creates a rebound effect that fragments your lighter sleep stages and shortens REM periods. Even two drinks in the evening can noticeably reduce REM time. The closer to bedtime you drink, the stronger the effect. If you’re specifically trying to increase REM sleep, reducing or eliminating evening alcohol is one of the most impactful steps available.
Medications That Suppress REM Sleep
Several widely prescribed medications reduce REM sleep as a side effect. The most significant are antidepressants. SSRIs, the most commonly prescribed class, have well-documented REM-suppressing effects. Older classes of antidepressants can suppress REM even more dramatically, and one type (MAOIs) can sometimes eliminate REM sleep almost entirely.
If you’re taking an antidepressant and noticing that your sleep feels unrefreshing or your dreams have disappeared (dreaming happens almost exclusively during REM), the medication may be a factor. This doesn’t mean you should stop taking it. But it’s worth discussing with whoever prescribed it, because some antidepressants affect REM less than others, and switching within the same class can sometimes help.
Treat Sleep Apnea if You Have It
Obstructive sleep apnea doesn’t just cause snoring and daytime fatigue. It specifically damages REM sleep. During REM, your muscles relax more deeply than in other stages, which makes your airway more likely to collapse. This means apnea events tend to cluster in REM periods, repeatedly pulling you out of the stage before it completes.
Research from UC Irvine found that low oxygen levels during REM sleep, not just the number of breathing interruptions, are linked to damage in brain regions critical for memory. The frontal and parietal lobes are especially active during REM and especially vulnerable to oxygen drops. If untreated apnea is fragmenting your REM sleep, it may be quietly interfering with the brain’s overnight memory maintenance. Treatment with a CPAP or similar device typically restores normal REM architecture within weeks.
Exercise Earlier in the Day
Regular aerobic exercise improves sleep quality broadly, including time spent in deeper sleep stages. But timing matters. Vigorous exercise close to bedtime raises your core temperature and releases stimulating brain chemicals that take time to clear. Johns Hopkins Medicine recommends finishing intense exercise at least one to two hours before bed to give your body time to wind down. Morning or afternoon workouts tend to produce the best sleep outcomes. You don’t need to avoid all evening activity, though. Light stretching or a walk after dinner won’t interfere.
Caffeine’s Real Effect on REM
Caffeine is often blamed for reducing REM sleep, but the evidence is more nuanced. A review of ten studies found that caffeine did not significantly delay the onset of REM sleep. Its primary effect is on falling asleep and staying asleep. Because caffeine has a half-life of about five to six hours (meaning half the caffeine from your afternoon coffee is still active at bedtime), it can reduce your total sleep time, which indirectly cuts into REM by shortening those crucial final sleep cycles. The practical takeaway: caffeine doesn’t selectively target REM, but if it’s making you sleep less overall, you’re losing REM along with everything else. A reasonable cutoff is early to mid-afternoon for most people.
Consistency and Wake Time
Your body’s internal clock heavily influences when REM sleep occurs. REM is linked to your circadian rhythm, not just how long you’ve been asleep. Going to bed and waking up at wildly different times on weekdays versus weekends disrupts this rhythm and can shift when your body attempts REM periods, sometimes into windows when you’re already awake.
A consistent wake time is more important than a consistent bedtime. Your body anchors its circadian rhythm primarily to when you wake up and see light. Keeping your wake time within a 30-minute window, even on weekends, helps your brain reliably schedule its longest REM periods during the final hours of your sleep. If you need to catch up on sleep, going to bed earlier is less disruptive than sleeping in late, because it extends sleep on the front end while preserving your circadian timing.
What REM Sleep Actually Does for You
Understanding why REM matters can help motivate these changes. During REM, your brain consolidates emotional memories, processes the experiences of the day, and performs what researchers describe as critical maintenance on memory systems. Your brain is nearly as active during REM as it is when you’re awake, but your voluntary muscles are temporarily paralyzed (which is why you don’t act out your dreams).
People who consistently get too little REM sleep report more difficulty with emotional regulation, problem-solving, and creative thinking. Over the long term, chronically low REM sleep is associated with changes in white matter in the brain, particularly in regions responsible for memory. The good news is that when you remove the barriers, whether that’s short sleep, alcohol, an untreated sleep disorder, or an inconsistent schedule, REM sleep typically rebounds quickly. Your brain prioritizes it once given the opportunity.