The Best Time to Check Your Hormones For Perimenopause
Blood tests don't diagnose perimenopause — but timing them right makes them more useful.
We tend to trust lab testing because numbers feel definitive. But hormone testing can’t diagnose perimenopause on its own. That’s because your hormone levels naturally rise and fall throughout your menstrual cycle, and those swings become even more unpredictable as you get closer to menopause.
But that doesn’t mean hormone tests aren’t valuable.
When interpreted alongside your age, menstrual history, and symptoms, hormone tests can show whether your hormones are changing in ways that fit patterns typical of perimenopause.
“Biology is dynamic and blood work is a tool alongside the clinical picture,” says Natalie Kunsman, M.D., a family physician who specializes in hormone health. “Which is why Hone doctors tell women not to worry too much about the testing window because we’re looking at the whole picture.” However, if you’re not working with Hone, there are times during your cycle when testing will yield the most accurate results.
Here’s how to time hormone testing to get the clearest picture of what’s happening in your body.
About the Experts
Natalie Kunsman, M.D., is a family medicine doctor who specializes in hormone health.
Jim Staheli, D.O., is the Medical Director for Hone Health and a family medicine doctor who specializes in longevity and hormone optimization.
The Best Time to Test If Your Cycles Are Regular
If your cycles are still regular, the two most informative testing windows are early in your cycle for follicle-stimulating hormone (FSH), and about a week after ovulation for estrogen and progesterone.
- Days 2–5 (Early Follicular Phase): FSH is a hormone the brain produces to signal the ovaries to develop a follicle and release an egg. In a healthy cycle, FSH rises briefly at the start of each cycle to kick off follicle development, then drops back down once the ovaries release an egg. Testing early in the cycle — before the ovaries released an egg — captures FSH at its natural baseline. If that baseline reading is elevated, it may suggest that ovarian function is beginning to decline.1
- Days 19–21 (Mid-Luteal Phase): About 5–7 days after ovulation, progesterone reaches its peak while estradiol levels begin to fall. Testing here confirms whether you ovulated and if your body is producing enough progesterone and estrogen to prepare the uterus for a possible pregnancy. It’s one of the clearest windows for assessing how well your ovaries are functioning and whether shifts consistent with perimenopause are beginning.2
Because hormone levels can fluctuate significantly from one cycle to the next, doctors typically repeat key tests over several cycles to confirm whether a result was a one-time fluctuation or part of a pattern.3
When to Test Estrogen and Progesterone in Perimenopause
In a regular cycle, the best time to test estrogen and progesterone for perimenopause is during the mid-luteal phase — around days 19–21, when both hormones are at or near their peak. Testing at this window reveals whether the two hormones are in the right balance relative to one another.
When you ovulate, progesterone rises sharply to prepare the uterus for a possible pregnancy. Estrogen begins to decline because its job — stimulating the growth of the uterine lining ahead of ovulation, is done for the cycle. This hormonal handoff is one of the clearest signs that ovulation occurred and that your ovaries are functioning normally.4
As you get closer to menopause, declining ovarian function causes two things to happen:
- You ovulate less often, so progesterone doesn’t surge in a regular pattern
- Follicle activity becomes erratic, causing estrogen to fluctuate unpredictably
When the ratio between estrogen and progesterone is not in the expected range — for example, progesterone didn’t rise enough, estrogen stayed too high, or both — it suggests ovulation was weak or didn’t occur. If your doctor sees this pattern in your blood work over multiple cycles, it’s more likely that you’re in perimenopause.
Testing timing matters because if progesterone is low 19-21 days after your last period (the point when it’s supposed to be at its highest), that’s a much stronger signal of perimenopause than a low reading taken earlier in the cycle, when progesterone is naturally low. “Testing too early in the cycle can return normal-looking results even when symptoms are very real,” notes Jim Staheli, D.O., Medical Director for Hone Health.
When to Test Follicle-Stimulating Hormone (FSH)
Follicle-stimulating hormone (FSH) fluctuates from cycle to cycle, especially during perimenopause. It’s easiest to interpret at the beginning of your menstrual cycle, typically days 2–4, when levels are naturally at baseline.
FSH rises briefly at the start of every cycle to signal the ovaries to prepare for ovulation. In premenopause, FSH drops back down quickly once the ovaries release an egg. In perimenopause, the ovaries produce eggs less efficiently, so the brain has to signal for more FSH to get the same result. Over time, that baseline level — what’s measurable on days 2–4, before any follicle has had a chance to respond — begins to creep upward. A rising baseline FSH is one of the earliest hormonal hallmarks of perimenopause.
Because FSH can fluctuate significantly from one cycle to the next, doctors measure it over multiple cycles to confirm whether changes are consistent with perimenopause or point to another condition, such as premature ovarian insufficiency (where the ovaries stop functioning normally before age 40) or hypothalamic amenorrhea (lack of periods often caused by stress, low body weight, or over-exercise).5
When to Test Testosterone
The best time to test testosterone is early in the morning, between 7–10 a.m.6 Although testosterone levels don’t fluctuate much across the menstrual cycle, they do fluctuate over the course of a day, and they’re at their highest in the morning.
Doctors may check testosterone during a perimenopause workup to establish a baseline and to rule out abnormally low levels which could contribute to symptoms like fatigue, low libido, and brain fog.
Getting an accurate measure of your testosterone is critical if your doctor prescribes testosterone therapy. Women have much lower testosterone levels than men, so dosing needs to be far more precise. Follow-up testing allows your doctor to fine-tune your dose and keep testosterone in the optimal range as your body’s needs change.
Testing If Your Periods Are Irregular
Once your periods become irregular, there may no longer be a “best” day to test for perimenopause.
Irregular cycles usually mean you’re ovulating inconsistently. With fewer healthy follicles, your brain produces more FSH to try to stimulate the ovaries to release an egg. Estrogen fluctuations become more erratic, progesterone falls, and the normal balance between the two begins to shift. A widening gap between estradiol and progesterone during the second half of the cycle can be an early sign that the menopausal transition is underway.7
To interpret these numbers, doctors check your results against reference ranges for each stage of the menopausal transition (premenopause, perimenopause, and menopause) to determine the best match, and also factor in your symptoms, age, and medical history.
Because hormone levels can shift significantly from one month to the next, Hone doctors test hormone levels every few months to track whether levels are stabilizing, declining, or responding to treatments like hormone replacement therapy (HRT). In perimenopause, patterns over time are more informative than any single snapshot.
Other Tests to Consider in Perimenopause
Perimenopause shares symptoms with several other common conditions that impact women in midlife, so part of hormone testing involves ruling those out. Depending on your symptoms, your doctor may order:
- TSH and free T4 to check for thyroid disease, which can cause fatigue, mood changes, and irregular periods8
- Prolactin if menstrual changes are otherwise unexplained, since elevated levels can disrupt the cycle9
- DHEA-S and cortisol if an adrenal condition is suspected, since adrenal hormones may affect energy, mood, and cycle regularity10 11
The Bottom Line
If your menstrual cycles are still regular, the best time to check your hormone levels for perimenopause is days 19–21 of your monthly cycle. If your periods have become irregular, doctors rely less on cycle timing and more on hormone ratios and patterns over time. In either case, doctors interpret results alongside symptoms, age, and medical history.
FAQs
When is the best time of day for a perimenopause test?
Morning is the best time to test your hormones for perimenopause. Research shows that estradiol and progesterone both rise in the first hour after waking in women who are still having regular menstrual cycles. Testosterone should be collected in the morning between 7–10 a.m., when levels are naturally at their highest.
Does birth control affect a hormone test?
Yes. Hormonal contraceptives suppress natural hormone production and significantly alter FSH, estradiol, and progesterone levels, making results unreliable for testing perimenopause.
- If you’re under 40 and your doctor suspects premature menopause, you’ll need to pause the combined oral contraceptive pill for at least three months before testing to give the contraceptive hormones time to fully leave your system.
- For perimenopause testing above age 40, some experts recommend a break from hormonal contraceptives of at least two weeks, but ask your doctor what they advise.
Do I need a blood test before starting hormone replacement therapy in perimenopause?
Since perimenopause is diagnosed primarily based on age, symptoms, and medical history, you don’t need blood tests to get a prescription for hormone replacement therapy. However, doctors strongly encourage testing to rule out conditions with overlapping symptoms, identify emerging health risks, and guide more personalized treatment decisions.
Should hormone levels be checked during perimenopause?
Yes, hormone levels should be tested in perimenopause, even though they can’t diagnose it. Blood tests in midlife can help your doctor personalize any hormone treatment to your specific levels, rule out conditions with similar symptoms, and catch emerging health issues like cardiovascular disease early, when they’re most treatable.
Which hormones should I get tested during perimenopause?
Most hormone panels include estradiol, progesterone, follicle-stimulating hormone (FSH), testosterone, and sex hormone-binding globulin (SHBG). Depending on your symptoms, your doctor may also order thyroid, or other tests to rule out conditions that can mimic perimenopause.
Can I test for perimenopause at home?
Several types of at-home perimenopause tests are available, including finger-stick blood, saliva, and urine kits. However, it can be difficult to interpret results from an at-home perimenopause test without knowing where you are in your cycle and without stage-specific reference ranges for context. A clinician can recommend the right tests, ensure they’re timed appropriately, and interpret results alongside your symptoms and medical history.
How much does a perimenopause blood test cost?
Perimenopause blood tests cost from $65–$500 out of pocket, depending on the hormones included, your geographic location, and whether you use insurance. Hone Health offers perimenopause blood tests for $65, which includes 50+ biomarkers. Insurance may cover hormone testing ordered to rule out specific conditions such as thyroid disease or premature ovarian insufficiency.
Tal, Reshef, et al. (2017) Ovarian Reserve Testing: A User’s Guide
↑Practice Committees of the American Society for Reproductive Medicine and the Society for Reproductive Endocrinology and Infertility (2021) Diagnosis and Treatment of Luteal Phase Deficiency: A Committee Opinion
↑Practice Committees of the American Society for Reproductive Medicine and the Society for Reproductive Endocrinology and Infertility (2021) Diagnosis and Treatment of Luteal Phase Deficiency: A Committee Opinion
↑Nanette Santora, et al. (2021) The Menopause Transition: Signs, Symptoms, and Management Options
↑Tal, Reshef, Seifer, David B. (2017) Ovarian reserve testing: a user’s guide
↑Algburi Sr, Hatem D., et al. (2023) Diurnal Variation of Serum Total Testosterone in Women: A Single-Center Study From Basrah
↑Prior, JC (2011) Progesterone for Symptomatic Perimenopause Treatment – Progesterone politics, physiology and potential for perimenopause
↑Lumsden, Mary Anne, et al. (2025) European Society of Endocrinology clinical practice guideline for evaluation and management of menopause and the perimenopause
↑Petersenn, Stephan, et al. (2023) Diagnosis and management of prolactin-secreting pituitary adenomas: a Pituitary Society international Consensus Statement
↑Bancos, Irina, Endocrine Society (2022) Adrenal Hormones
↑Papadopoulou-Marketou, Nektaria, et al. (2023) Adrenal Androgens and Aging
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About the author
Lauren Ramakrishna is a freelance writer who covers health. Her work has appeared on digital sites by Good Housekeeping, Redbook, and Woman's Day, among others.
About the reviewer
Dr. Shelly Chvotzkin, D.O., F.A.C.O.O.G., is a physician board certified in obstetrics and gynecology. She is a member of the American College of Osteopathic Obstetricians and Gynecologists (ACOG), the American Osteopathic Association (AOA), the American Society for Colposcopy and Cervical Pathology (ASCCP) and the Menopause Society (formerly known as the North American Menopause Society or NAMS).
