Sleep after 45 — the hours look the same, the quality doesn't.

Your tracker says seven hours, same as a decade ago — yet you wake unrested. What changes after 45 isn't the clock, it's the architecture: less deep and REM sleep, more waking. The good news is a small set of well-evidenced habits genuinely move sleep quality.

What actually changes

Across the lifespan, slow-wave (deep) sleep and REM both decline, and time awake after first falling asleep rises — so the same hours yield lighter, more fragmented sleep. Deep sleep is when the brain does much of its overnight maintenance; REM supports mood and memory. For women, the perimenopausal drop in progesterone and hot flashes that fragment the night add to it.

The levers that work, in order

• Temperature — a cool room (~65–68°F) is the highest-leverage change; a warm bath ~90 min before bed helps via the rebound drop.
• Morning light — bright outdoor light early anchors your rhythm; indoor light usually isn't enough.
• Consistent timing — a regular sleep/wake time beats chasing a number of hours.
• Alcohol timing — alcohol fragments the back half of the night; move drinks earlier.
• Treat hot flashes — if night sweats wake you, discuss options with a menopause-trained clinician (HRT explainer).

For persistent insomnia, CBT-I is the first-line, best-evidenced treatment — more durable than sleeping pills.

What's oversold

Sleep trackers don't improve sleep by themselves, and fixating on the score can worsen it. Melatonin works at low doses (~0.3–1 mg) — the 5–10 mg tubs aren't more effective. CBD has thin sleep evidence, and magnesium is a minor lever at best (our take). No 'metabolism' supplement fixes sleep architecture.