The REM Reset: How to Get More REM Sleep When You’re Already Doing Everything Right

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No screens before bed. Dark room. Consistent bedtime. And you still wake up exhausted, or wide awake at 3am staring at the ceiling.

If that sounds familiar, it usually isn’t a discipline problem. It’s often a REM problem, and the causes start long before your head hits the pillow.

Not all sleep does the same job

Your body cycles through sleep stages about every 90 minutes, four to six times a night:

• Light sleep: the transition stage, when your body begins to relax

• Deep sleep: physical repair, immune function and growth hormone

• REM sleep: memory, emotional processing and clearing waste from the brain

REM is concentrated in the second half of the night. So anything that breaks up your early-morning sleep cuts into REM the most.

When you don’t get enough REM, you feel it: foggier thinking, a shorter fuse and less ability to handle stress. Over time, low REM is linked to poorer cognitive performance and mood regulation.

A quick note on your sleep tracker

Wearables like smartwatches and rings are great for spotting patterns, like a later bedtime or a rough night after a few glasses of wine. But they aren’t the most accurate judge of REM.

In a sleep lab, REM is identified by measuring brain waves, eye movements and muscle tone. Your watch or ring can’t see any of that. It estimates your sleep stages from things like heart rate and movement, so its REM number is an educated guess.

So if your tracker says you got little to no REM, don’t let it get in your head. Stressing over your sleep score can actually make sleep worse. Use your wearable for trends over weeks, not a verdict on a single night, and pay more attention to how you actually feel when you wake up.

A different question

Typical sleep advice asks: “What’s in your way right before bed?”

Root-cause work asks: “What’s happening in your body all day that decides whether REM is even possible?”

Here are the three categories I look at.

Root Cause #1: Hormones

Overnight blood sugar dips. When your blood sugar drops during the night, your body releases cortisol and adrenaline to bring it back up. That stress response pulls you out of REM. It often looks like waking between 2 and 4am, feeling “wired but tired,” or waking up hungry.

What helps: A balanced dinner with protein, fat and fiber. A small protein-and-fat snack if dinner was light. Limiting evening alcohol, and avoiding a very low-carb dinner.

Cortisol rhythm. Cortisol should be lowest at night and rise in the morning. Chronic stress can flatten or even flip that curve, leaving your nervous system too revved up for REM. You might notice racing thoughts at lights-out or a “second wind” late in the evening.

What helps: Morning sunlight, regular meal times, an evening wind-down routine and an earlier caffeine cutoff.

Progesterone and thyroid. For women, progesterone has a calming effect, and it naturally declines in perimenopause. That’s a common, under-discussed reason sleep gets lighter with age. An underactive or overactive thyroid can also fragment REM.

What helps: Tracking cycle-related changes, asking for a full thyroid panel (not just TSH), and working with a practitioner on hormone support.

Root Cause #2: Nutrient gaps

Your brain needs raw materials to build a REM state. Three gaps show up often:

• Magnesium and B6: key helpers in making the brain chemicals that calm you down and produce melatonin. Stress, alcohol and processed diets all deplete magnesium.

• Iron (ferritin): low iron stores, even without anemia, are linked to restless, lighter sleep. Ask for ferritin specifically, not just hemoglobin.

• Omega-3s and protein at dinner: DHA is concentrated in the brain, and low intake is tied to less REM. Protein at dinner provides the building blocks for melatonin.

What helps: Leafy greens and pumpkin seeds for magnesium, iron-rich foods paired with vitamin C, fatty fish two to three times a week, and protein at dinner. If you’re thinking about supplements, test first so you know what you actually need.

Root Cause #3: The physical disruptors people miss

Alcohol. That glass of wine may help you fall asleep, but it suppresses REM in the first half of the night. Then, as it wears off, you get lighter, more broken sleep. That’s the mechanism behind the classic 3–4am wake-up. Even one drink a few hours before bed can change the night. Though this is not necessarily the case for everyone and can change with age.

What helps: Finish drinks at least 3 hours before bed, or swap in a non-alcoholic wind-down ritual.

Mild sleep apnea. Your airway muscles relax the most during REM, so even mild apnea, with no obvious snoring, robs REM specifically. If you wake up unrefreshed no matter what, ask your doctor about a sleep screening.

Body temperature. Your core temperature needs to drop for REM to happen. A warm bedroom, perimenopause or heavy bedding can all get in the way.

What helps: Keep your bedroom around 65–68°F, use breathable bedding, and try a warm bath 1–2 hours before bed. It sounds backwards, but it helps your body cool down afterward. I recently switched to this lighter comforter for exactly this reason. It’s soft and cozy without being too heavy, so I don’t overheat at night.

Gut health. Most of the body’s serotonin is made in the gut, and gut health affects the communication between your gut and brain. Ongoing gut issues can be one more piece of the sleep puzzle.

What helps: More fiber and more variety of plants, less processed food, and digging deeper if digestion has been off for a while. I personally love having popcorn as a snack - not the butter filled bagged kind - the home popped with a little olive oil and seasoning of choice. This is the popcorn maker I use!

Where to start

You don’t need to fix everything at once. One step, one change at a time.

1. Track first. For one week, note when you wake up, how groggy you feel in the morning, and when you have alcohol and caffeine. Don’t change anything yet.

2. Pull the biggest lever. Match the fix to your pattern:

• Waking at 2–4am → look at blood sugar first

• Evening drinks → start there

• Racing mind at bedtime → focus on cortisol and stress

3. Test instead of guessing. If the pattern sticks around, functional labs can show what’s actually driving it. Markers worth asking about:

• Fasting insulin and HbA1c

• A 4-point salivary cortisol test

• A full thyroid panel

• RBC magnesium, B6 and ferritin

• Omega-3 index

• A comprehensive stool test

Ready to find your root cause?

If you’re doing everything “right” and still not sleeping well, this is exactly the kind of puzzle I love helping people solve. My 1:1 consulting includes a detailed look at your labs and symptoms to find what’s really getting in the way of your rest.

Not ready for that yet? Start with The Livable Fix, my free root-cause checklist for busy professionals. Download it below.

Livable mindset, always —Harriet 💛