In my last post, Perimenopause and Sleep: Why Progesterone Matters, I walked through why sleep often unravels in perimenopause: progesterone falling as ovulation becomes less reliable, estrogen swinging, hot flashes, a bladder that wakes you, and fragmented sleep shifting cortisol. This post picks up the question I hear next: what actually helps, and how strong is the evidence?
As always, I’ll share what the research supports and where it runs out. But research isn’t the only thing that shapes how I practise. Some of what I’ve learned during my clinical training and in practice hasn’t been well studied yet, and some of it may still be worth exploring, as long as we’re clear about what’s established and what isn’t.
What the research says about progesterone therapy
What we know so far, mostly from postmenopausal women
Most of the research on progesterone and sleep comes from women who are already postmenopausal. A 2021 meta-analysis of nine randomized trials (388 participants) found that micronized progesterone helped people fall asleep faster: pooling four of the trials, sleep onset improved by about 7 minutes on average, with no significant change in total sleep time or sleep efficiency. Self-reported sleep improved in most of the trials [1]. Small sleep-lab studies add an interesting detail. In one study of eight women, progesterone made no difference on an ordinary night, but when sleep was deliberately disrupted, it cut time awake by about half and increased deep sleep [2]. A crossover study of 10 women similarly found less time awake during the night [3].
For hot flashes and night sweats, a placebo-controlled trial of 133 postmenopausal women found that bedtime oral micronized progesterone reduced both over 12 weeks [4]. A 2026 retrospective study of 36 women in Japan found improved sleep onset and fewer awakenings at 3 months, but the benefit wasn’t seen at one year, and sleep got worse in women who hadn’t had sleep problems to start [5].
Perimenopause: research in progress
Perimenopause has far less research, and that’s an important gap. I’m aware of only one randomized trial of progesterone on its own in perimenopause: a Canadian trial of 189 women who were still having periods. The main outcome, a hot flash and night sweat score, didn’t differ from placebo, though the trial was underpowered. Women taking progesterone did report fewer night sweats and better sleep quality, without an increase in depressive symptoms [6].
Some of the stronger perimenopause sleep data come from combined therapy. In a year-long trial of 172 women in the menopause transition or early postmenopause, transdermal estradiol with intermittent progesterone helped women fall asleep faster and wake less often, and those effects held even after accounting for changes in hot flashes and mood [7]. More research is under way: at least one trial is now comparing hormone therapy with CBT for insomnia in women in late perimenopause [8].
Why might perimenopause be different? This is a hypothesis rather than an established finding, but it’s worth considering. In perimenopause, progesterone often falls while estrogen swings high and low, which is why the Canadian researchers framed progesterone as a “replacement-type” therapy for women who are still cycling [6]. That could make progesterone especially relevant at this stage. But as I mentioned in Part 1, those cycle-to-cycle swings also make a treatment’s effect harder to measure. For now, we’re still learning, and the answer may well vary from woman to woman.
Not all progesterone is the same
I’m often asked about the different forms of progesterone, so here’s what the evidence says about each one.
Oral micronized progesterone. This is body-identical progesterone taken as a capsule, and it’s the form used in almost all of the sleep research above. It also has the strongest evidence for protecting the uterine lining in anyone with a uterus who takes estrogen. A systematic review found that oral micronized progesterone protects the lining when taken for 12 to 14 days a month. The studies it looked at followed women for up to 5 years, so we have less data beyond that point [9, 10].
Synthetic progestins. These are different molecules from the progesterone your body makes, and they’re used in some birth control and hormone therapy. They aren’t interchangeable when it comes to sleep. In a study of women taking estrogen, both groups reported better sleep and fewer menopausal symptoms, but only those taking micronized progesterone showed improvements on sleep-lab testing, including better sleep efficiency and less time awake during the night [11].
Topical progesterone (creams and gels). This is the form I’m asked about most, and the evidence is limited. In the best controlled trial, 80 postmenopausal women using a progesterone cream for 3 months saw no improvement in hot flashes, mood, or other symptoms compared with placebo [12]. In a small study of 10 postmenopausal women, progesterone absorbed through the skin rose slowly in blood and peaked around 8 to 9 hours after application. Saliva levels also ran higher than blood levels, which means saliva testing doesn’t reflect what’s circulating [13]. I didn’t find a randomized trial that tested progesterone cream for sleep. The same systematic review found that topical progesterone does not protect the uterine lining, so it shouldn’t be relied on for that purpose in someone taking estrogen [9, 10].
Vaginal progesterone. Progesterone can also be absorbed through vaginal tissue. The same systematic review looked at vaginal progesterone and found that it may protect the uterine lining when used for at least 10 days a month, or every other day, although this is considered an off-label use. These studies followed women for up to 3 to 5 years [10]. I didn’t find studies testing vaginal progesterone for sleep in menopause.
Progesterone and scope of practice
The form matters for scope of practice, too. In Ontario, naturopathic doctors with the required prescribing training can prescribe bioidentical progesterone in topical or suppository forms, but not the oral capsule used in most of the research above. For anyone with a uterus who takes estrogen, a progestogen is needed alongside it to protect the lining, and the strongest evidence for that role is for oral progesterone [9, 10]. If oral micronized progesterone looks like a good fit, we’ll decide together how to move forward. With your consent, I’m happy to reach out to your family doctor or nurse practitioner directly, or I can put together a summary of the options for you to discuss with them yourself. Either way, the goal is care that works for you. (I go into how this differs between Ontario and Manitoba in Bioidentical Hormone Therapy: What the Evidence Actually Says.)
The bottom line on progesterone
The evidence points to some real benefits, particularly for falling asleep and for night sweats. The research suggests progesterone may be most helpful when something is already disrupting sleep, such as night sweats or hot flashes. The effects are modest, though, and it may not have the same results for all women. Most of the evidence is for oral micronized progesterone in postmenopausal women, and research in perimenopause is still catching up.
Progesterone also isn’t the only option, and it isn’t the right fit for everyone. That’s where herbs and supplements can come in, either alongside hormone therapy or on their own.
Herbs and supplements I often reach for
Ashwagandha. A meta-analysis of five randomized trials (400 participants) found a small but significant improvement in sleep, larger in people with insomnia and in trials of 8 weeks or longer [14]. A trial in 80 people found improved sleep onset and sleep efficiency in those with insomnia [15]. For perimenopause specifically, an 8-week trial in 100 women found improvement in overall menopausal symptom scores, including the urogenital domain [16], and a second 8-week trial in 60 women reported fewer hot flash events [17]. Both trials also reported shifts in hormone levels, which is unexpected and would need confirmation by independent researchers. These are small, short trials, so I see ashwagandha as a reasonable option to discuss, particularly if night sweats and stress are both in the picture. Safety matters too: rare cases of liver injury have been reported, usually resolving within months of stopping [18], and one small trial found ashwagandha changed thyroid markers in people with subclinical hypothyroidism [19]. If you have a thyroid condition, take thyroid medication, or have liver concerns, check with your practitioner first.
Black cohosh. Black cohosh is one of the most studied herbs for menopause, and it has a trial that measured sleep directly in a sleep lab. In a 6-month randomized trial of postmenopausal women with sleep problems, black cohosh improved sleep efficiency and reduced time awake during the night compared with placebo, and hot flash and physical quality-of-life scores also improved [20]. Only 42 women completed the trial, so these results are encouraging but preliminary. For hot flashes more broadly, the evidence is mixed. A Cochrane review of 16 trials (2,027 women) found black cohosh didn’t reduce hot flash frequency more than placebo, though the authors noted the trials were often of unclear quality and called for better-designed studies [21]. As with ashwagandha, rare cases of liver injury have been reported, so the same caution applies: check with your practitioner first if you have liver concerns, and stop and seek care if you notice signs like yellowing of the skin or eyes, dark urine, or unusual fatigue [22].
Valerian. Valerian root has a long history of use for sleep, and it has one well-designed trial in women at this stage of life. In a 4-week randomized trial of 100 postmenopausal women with insomnia, sleep quality improved more with valerian than with placebo: about 30% of women taking valerian improved, compared with 4% taking placebo [23]. It’s a single, short trial that relied on questionnaires, so it’s a promising start rather than strong evidence.
L-theanine. L-theanine is an amino acid found naturally in tea, and it’s often used to support calm without sedation. A 2025 meta-analysis of 19 studies (897 participants) found improvements in self-reported time to fall asleep, daytime functioning, and overall sleep quality, though most of the products tested combined L-theanine with other ingredients [24].
The study most relevant to this post was done in postmenopausal women. In a small crossover study of 20 women, taking L-theanine before bed for six nights reduced sympathetic (“fight or flight”) nervous system activity during sleep, with a trend toward more parasympathetic (“rest and digest”) activity [25]. That may be relevant if you tend to feel “wired” at night. It’s a small study that measured nervous system activity rather than sleep itself, though, so it points to a possible mechanism rather than proving a benefit.
Other trials add to the picture. In a 4-week crossover trial of 30 healthy adults, sleep quality scores improved [26]. In an 8-week trial of 46 adults with generalized anxiety disorder, L-theanine didn’t reduce anxiety more than placebo, but participants reported greater satisfaction with their sleep [27]. In a 6-week trial of 98 boys with ADHD, sleep measured with a wrist monitor was more efficient with L-theanine than with placebo [28]. On brain waves, L-theanine appears to influence alpha activity, the rhythm of relaxed wakefulness, though results vary between studies [29, 30]. I haven’t found studies in perimenopausal women specifically.
Magnesium. A meta-analysis of three small trials in older adults found magnesium shortened time to fall asleep by about 17 minutes, without a significant change in total sleep time [31]. Magnesium bisglycinate improved insomnia severity in a trial of 155 adults, though the effect was small and benefit appeared larger in people with low dietary magnesium [32]. A 3-week trial of magnesium L-threonate in 80 adults aged 35 to 55 reported improved sleep measures [33]; it’s a small, short study, and a correction has been published. The reasoning for threonate is that it raised brain magnesium in rats [34], but in a later human trial, strong placebo effects meant its sleep effects couldn’t be determined [35]. I couldn’t find solid human evidence that either form measurably raises brain magnesium or that one is better for sleep, so the choice between them rests on tolerance, cost, and your individual response.
I cover magnesium, L-theanine and adaptogens in more depth in Hormones and Mental Health: What’s Actually Going On.
Don’t skip the foundations: sleep habits and movement
Some of the strongest evidence for menopausal sleep isn’t for a hormone or a supplement at all.
CBT for insomnia (CBT-I). CBT-I is a structured program that helps retrain your sleep. It includes techniques for adjusting sleep timing, building a stronger link between bed and sleep, and working with the thoughts that keep you awake. In a trial of 106 peri- and postmenopausal women with insomnia and hot flashes, six phone sessions of CBT-I over 8 weeks reduced insomnia severity about twice as much as menopause education did [36].
Sleep restriction. Sleep restriction is one of the core pieces of CBT-I. It temporarily limits your time in bed to the time you’re actually sleeping, then gradually extends it as sleep becomes more consolidated. In a trial of 150 postmenopausal women with insomnia, sleep restriction on its own improved insomnia, though full CBT-I helped more, particularly with staying asleep [37]. It can feel hard at first, so it’s best done with guidance.
Movement. In a 12-week trial of sedentary women in late perimenopause and postmenopause, aerobic exercise three times a week didn’t reduce hot flashes, but it modestly improved insomnia symptoms and sleep quality [38].
These approaches pair well with everything above, and they’re a good place to start.
Putting it together
The research points to some real benefits here, though no single option will be the right fit for every woman. Progesterone has the most direct evidence, mainly for falling asleep, night sweats and perceived sleep quality, though most of it comes from postmenopausal women. The herbs and supplements have smaller, shorter studies and little perimenopause-specific research. Behavioural approaches, especially CBT for insomnia, have some of the strongest evidence for menopausal insomnia [39], and international menopause experts recommend both hormone therapy and CBT for insomnia as tailored options for sleep [40].
My approach stays the same: test rather than guess, match the option to what’s actually driving your sleep, and adjust together as we learn how you respond. If you haven’t read it yet, Part 1 covers what may be driving perimenopausal sleep changes in the first place.
If this sounds like you, I offer virtual care in Ontario and Manitoba. You can book an appointment through Jane, or send me a question through the contact form.
General information only, not medical advice.
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