If you’ve been waking up at 3am like clockwork lately — wide awake, heart going a little, mind suddenly racing — you’re not imagining it, and you’re not broken. There’s a real, physiological reason this happens to so many women in their 40s and beyond, and it has less to do with stress itself and more to do with what’s happening to your blood sugar and your hormones while you sleep.

It starts with blood sugar

All night long, your liver has one job: keep your blood glucose steady so your brain has fuel. But as estrogen declines in perimenopause, the liver gets less efficient at that job. At the same time, you’re naturally losing some muscle mass during this life stage — and muscle is one of the body’s main storage sites for glucose. Less storage, a less efficient liver, and you’ve got a recipe for blood sugar dipping lower than it should overnight.

When that dip happens, your body treats it like an emergency. It releases cortisol and adrenaline to push glucose back up — and that hormonal jolt is often sharp enough to wake you right up. Not surprisingly, that tends to happen in the early morning hours, right around 3am, when overnight glucose is typically at its lowest point.

Why this hits harder in midlife specifically

Exercise physiologist Dr. Stacy Sims, who’s spoken about this at length with Andrew Huberman, points out that perimenopause shifts women toward a more sympathetically driven state — what she calls “tired but wired.” Baseline cortisol runs higher to begin with during this stage of life. So when that middle-of-the-night blood sugar dip triggers a cortisol response, your nervous system is already sitting closer to alert mode, which makes it much more likely to fully wake you rather than pass by unnoticed the way it might have in your 30s.

There’s also a piece involving progesterone. It breaks down into a compound called allopregnanolone, which acts on the same calming brain receptors targeted by prescription sleep aids. As progesterone naturally declines and fluctuates in this stage of life, that built-in buffering effect gets weaker — so the cortisol signal comes through louder than it used to.

What actually helps

This is genuinely good news, because it means 3am waking isn’t a mystery you have to just live with — it’s a mechanism, and mechanisms can be worked with.

A few things that make a real difference:

  • A small protein-and-fat snack before bed. Something like a few slices of turkey, a hard-boiled egg, or a spoonful of nut butter can help stabilize blood sugar through the night so it doesn’t dip as sharply.
  • Protein at every meal, consistently. Steady blood sugar during the day sets you up for steadier blood sugar at night.
  • Strength training. Building and maintaining muscle gives your body more glucose storage capacity, which directly supports overnight stability.
  • Being mindful of alcohol close to bedtime. It can cause blood sugar to spike and then crash later in the night — right around, you guessed it, 3am.

None of this requires a total lifestyle overhaul. It’s the same principle that runs through everything I coach: small, consistent shifts that work with your body’s actual physiology, not against it.

If 3am has become a regular visitor for you, know that it’s not a personal failing, and it’s not something you just have to accept. It’s your body sending you real information — and that information is something we can act on.

Strong feels good.