Why You Can't Sleep in Midlife And How to Fix It

Sims frames this as the essential first step before any supplements or cooling hacks. She observes that many women force themselves to stay up for partner connection time, overriding their biological signal. Over time, this pattern leads to chronic sleep disruption. The fix is low-tech: listen to your body, note the time fatigue hits, and gradually shift your bedtime to match it. For those unable to align (shift workers), she then layers on other interventions like tart cherry juice and adaptogens.

Sims details that in perimenopause, core temperature often fails to dip low enough, hovering near a wake-state temperature. The cold juice provides an external temperature assist while the cherry's melatonin boost bridges the neurochemical gap. She contrasts this favorably with OTC melatonin, which is dosed too high for women and can dysregulate natural circadian rhythms.

Sims argues that the typical 3–10 mg OTC doses are not designed for women's physiology and can fast forward negative changes to natural circadian rhythms. This is why she steers women toward food-based or adaptogen alternatives, reserving melatonin only for those under a specialist's care who can micro-dose.

Stacy Sims explains that women's circadian clocks run on a different rhythm than men's, causing melatonin to surge and sleepiness to arrive earlier — often around 9 or 9:30 p.m. rather than the 10:30 or later that partners may prefer. In typical households, after children go to bed, women may fight through that sleepiness to spend time with their partner. By doing so, they pass the natural sleep wave and then find themselves unable to fall asleep, leading to restless nights. Her first and most important advice is for women to tune into their own sleep drive: to notice when they naturally feel tired and wind down for bed at that time. This alone can dramatically improve sleep quality. For those whose schedule simply cannot align — such as shift workers — she then moves to other strategies to coax the body into parasympathetic mode and lower its core temperature.

Sims describes the natural sleep cycle: core temperature drops about one degree Fahrenheit, remains low, then rises with cortisol to prompt waking. Perimenopausal women, however, experience temperature oscillations that stay right at wake-temperature range, blocking deep sleep. Cold tart cherry juice offers two mechanisms simultaneously. The tart cherry increases the body's own melatonin synthesis, "riding the wave" of the natural circadian rise, so more melatonin is available to initiate and sustain sleep. The cold temperature of the fluid actively helps lower core temperature into the sleeping zone. This combination facilitates faster sleep onset and enhances delta-wave sleep. Sims explicitly recommends this over over-the-counter melatonin because the typical supplement dose is too high for women and can disrupt natural production and circadian timing. For women who need additional help, she suggests L-theanine and ashwagandha, which support the parasympathetic arm.

When the host asks whether a phase shift in melatonin affects when to stop drinking coffee, Sims responds that it depends on whether someone is a fast or slow caffeine metabolizer. For fast metabolizers, timing isn't a big deal. However, she adds a crucial caveat: in perimenopause, most women become more sensitive to caffeine. The exact mechanism is unclear, but she speculates it may involve changes in dopamine and adenosine receptors, to which caffeine tightly binds. This can manifest as jitters or a sense of panic, as the host notes many women report needing to quit coffee entirely. The research is preliminary because menopause has historically been understudied, but the clinical observation is strong enough to recommend that women who notice new sensitivity reduce their caffeine intake or avoid it in the afternoon.