Women's Hormone Tracking: When to Draw Each Marker for Accurate, Comparable Results
Female hormone blood work is fundamentally different from male hormone testing in one important way: timing. Estradiol, progesterone, LH, and FSH vary dramatically across the menstrual cycle - not by 10-20% as testosterone does in men, but by 5-10x depending on the phase. A progesterone result on day 7 of a 28-day cycle is not comparable to a progesterone result on day 21 - nor is either comparable to progesterone in men. This post covers what days to get bloodwork done for each female hormone, what each timing is indicative of, and how to interpret everything for post-menopausal women and those on hormonal contraceptives.
Overview of the menstrual cycle
A standard 28-day cycle can be divided into 4 phases. Female hormones typically peak and trough across these phases:
Day 1 is the first day of your period. All the timing references in this post use day 1 as a reference point. Note that a menstrual cycle can be anywhere between 21-35 days in a healthy reproductive-aged woman. The number of days between your periods is not as important as the phase. If your cycle is not 28 days, use proportional math to estimate the day of the phase (see examples below). For example: if your cycle is 35 days, day 15 would be roughly equivalent to day 20 in a 28-day cycle.
What to test for on which day
Estradiol (E2)
Early follicular (day 2-4): this is the standard reference point for estradiol. Estradiol levels are at their lowest and most consistent point in early follicular phase, making it suitable for comparison across cycles. This is the best time to test if you’re doing annual or semi-annual monitoring.
Peri-ovulatory: estradiol is typically peaking around ovulation. Estradiol levels during this phase can help estimate ovarian reserve, egg quality, and whether ovulation has occurred at an appropriate estradiol level.
Mid-luteal: estradiol should be consistently low during this phase, making it a good comparator for progesterone.
Progesterone
Progesterone is the hormone most affected by the menstrual cycle. In follicular phase it is virtually undetectable (<1 ng/mL), while in mid-luteal it can be as high as 5-20+ ng/mL, depending on the individual. A progesterone level <3 ng/mL during mid-luteal suggests inadequate progesterone support of the luteal phase (either from the corpus luteum or supplements).
It is critically important to test progesterone at the right time if you’re trying to assess luteal function. Testing too early (follicular phase) or too late (late luteal phase, before ovulation) will give you misleading information about progesterone levels.
Rule of thumb: if you’re interested in progesterone as an indicator of luteal function, test between days 19-22 in a 28-day cycle (or roughly 7 days after ovulation).
LH (Luteinizing Hormone)
Early follicular LH: this is the standard reference point for LH, comparable to early follicular FSH (see below). Early follicular LH:FSH ratio is a key indicator for PCOS - if it is consistently above 2:1 or 3:1, it suggests PCOS.
Peri-ovulatory LH: this is the LH surge that triggers ovulation. It is typically a very sharp spike that can be easily missed if testing is not done at the right time. For most women, it’s easier to track ovulation with urine LH strips than blood tests, due to the narrow testing window.
FSH (Follicle-Stimulating Hormone)
Early follicular FSH: this is the standard reference point for FSH. It is used to estimate ovarian reserve - consistently increasing FSH levels across multiple tests (even within the “normal” range) suggest diminished ovarian reserve.
A single high FSH reading on day 2-4 can also be a reason for concern, but it’s more important to look at the trend across multiple years. If FSH is slowly increasing with each year (e.g. from 6 to 9 to 13), it’s a sign of impending menopause.
Testosterone (total and free)
Testosterone levels in women are much lower and more consistent than in men, but they still follow the menstrual cycle pattern, peaking closer to ovulation. The most important consideration for testosterone is that it should be tested at the same phase of the cycle consistently, to allow for comparisons across tests.
If you’re doing cycle-specific hormone testing to screen for PCOS, it’s best to test testosterone in early follicular phase alongside other hormones.
SHBG
There isn’t much to say about SHBG - it’s not particularly sensitive to the menstrual cycle. Test it at the same time as other hormones, with the same timing considerations. Note that hormonal contraceptives dramatically increase SHBG levels, which in turn decrease free testosterone.
Thyroid markers
TSH, free T4, and free T3: thyroid hormones are not particularly sensitive to the menstrual cycle. Test them at any time, ideally in the morning.
Metabolic markers
Glucose, insulin, lipids, CBC, liver and kidney function: standard metabolic tests are not particularly sensitive to the menstrual cycle. Test at any time, with fasting as required.
Reference ranges for female hormone bloodwork
Special considerations
Post-menopausal women
As mentioned above, cycle timing considerations do not apply to post-menopausal women. Estradiol, progesterone, LH, FSH can be tested at any time. The reference ranges for these hormones will be different for post-menopausal women, so make sure to look at the relevant range.
Post-menopausal hormone reference ranges:
Note that women on hormone replacement therapy (HRT) should follow the same considerations as testosterone replacement therapy (TRT) in men: blood should be drawn at the same time relative to the HRT dose (trough).
Hormonal contraceptives
Combined estrogen-progestin contraceptives (the pill, patch, ring): these suppress endogenous LH and FSH, rendering estradiol, progesterone, testosterone, and SHBG tests largely uninformative about your endogenous hormone production. Testing timing considerations for the menstrual cycle do not apply while on combined hormonal contraceptives.
- LH and FSH will be suppressed, making them uninformative about your endogenous reproductive hormone levels.
- Estradiol will reflect exogenous estrogen (the pill), not your endogenous levels.
- SHBG will be artificially elevated (3-4x), suppressing free testosterone. This is a frequently overlooked reason why women on the pill have low libido and symptoms of androgen deficiency.
- Progesterone will be suppressed, depending on the specific contraceptive.
If you’re trying to understand your endogenous hormone levels while on combined hormonal contraceptives, it’s best to get off them for 2-3 months to allow your endogenous reproductive hormone production to resume, then get a baseline blood test. If you’re on a progesterone-only contraceptive (mini-pill, Mirena), consult your doctor about the best time to get bloodwork.
A practical protocol for most women
For most women, a comprehensive annual or semi-annual blood test can be done in one visit, on days 2-4 of your period. It should include:
- Estradiol
- FSH (important for ovarian reserve and menopause screening)
- LH (important for assessing LH:FSH ratio for PCOS)
- Testosterone (total and free)
- SHBG
- Prolactin
- DHEA-S
Additionally, a mid-luteal progesterone test (days 19-22) can be done if you’re specifically interested in luteal function. Metabolic, thyroid, and lipid markers can be tested at any time, with morning draws preferred for TSH.
Not medical advice. Consult a licensed healthcare provider for clinical interpretation and treatment decisions.
Posted Aug 27, 2026, 1:04 PM UTC