Follicle-stimulating hormone (FSH)
FSH ranges depend on sex, cycle phase and menopause. Upper limits for women who still have periods run from about 9 to 21.5 mIU/mL by source, and two bodies use 25 as a cut point in the menopausal transition and in early ovarian insufficiency. In one cohort, FSH above 10 did not predict natural conception. Results vary between cycles.
- Status
- A blood test ordered by a clinician and also sold direct to consumers by some US laboratories. FDA classifies follicle-stimulating hormone test systems as class I devices, exempt from premarket notification [1].
- Measures
- The amount of follicle-stimulating hormone in blood, a hormone that stimulates the ovaries to produce eggs in women and the production of sperm in men [2].
- Also called
- FSH, follicle stimulating hormone, follicle-stimulating hormone, follitropin, FSH blood test, serum FSH, FSH serum, basal FSH, day 3 FSH
- Tested for
- menopause, perimenopause, irregular or absent periods, fertility testing, ovarian reserve, early menopause, low sperm count, male infertility, early or late puberty
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Linked in research2
- LimitedLimited evidence: in men seen for infertility, higher FSH went with abnormal sperm counts, and FSH above 7.6 mIU/mL went with azoospermia caused by failed sperm production.
- LimitedOne cohort found FSH levels and their change over 4 years predicted spine and hip bone loss through the menopausal transition, while estradiol changes did not.
Reported risks0
No risks sourced yet.
Reference ranges
Each range is the one its source published, in mIU/mL. Also reported in IU/L. Where sources differ, each is shown.
US National Library of Medicine, MedlinePlus, women who are still menstruating
Women who are still menstruating, with no cycle phase stated · [2]
| Range | What the source calls it |
|---|---|
| below 4.7 mIU/mL | No name given |
| 4.7 to 21.5 mIU/mL | "normal" |
| above 21.5 mIU/mL | No name given |
Printed as 4.7 to 21.5 mIU/mL (4.5 to 21.5 IU/L), so the page gives two different lower limits for one range. The mIU/mL figure is used here. It is one range for the whole menstrual cycle. MedlinePlus states that ranges may vary slightly among laboratories and names no assay. It also prints ranges for before and during puberty, which are not shown here [2].
US National Library of Medicine, MedlinePlus, women after menopause
Women after menopause · [2]
| Range | What the source calls it |
|---|---|
| below 25.8 mIU/mL | No name given |
| 25.8 to 134.8 mIU/mL | "normal" |
| above 134.8 mIU/mL | No name given |
Printed as 25.8 to 134.8 mIU/mL (25.8 to 134.8 IU/L). It names no assay [2].
Schüring and colleagues, 2016, Siemens Advia Centaur immunoassay, follicular phase
Women aged 25 to 44 with regular cycles, follicular phase, days 3 to 5 after the start of a period · [3]
| Range | What the source calls it |
|---|---|
| below 4.07 mIU/mL | No name given |
| 4.07 to 12.9 mIU/mL | "reference interval" |
| above 12.9 mIU/mL | No name given |
The 2.5th and 97.5th percentiles in 139 women seen at one German university hospital, who had cycles of 25 to 35 days and had used no hormonal contraceptives for at least three months. The median was 7.58 mIU/mL. Of everyone in the study, 96% were of European descent. The study was supported by the hospital's laboratory and by the assay's maker. The maker's own interval for this phase, reprinted in the paper, was 2.5 to 10.2 [3].
Schüring and colleagues, 2016, Siemens Advia Centaur immunoassay, luteal phase
Women aged 25 to 44 with regular cycles, luteal phase, days 21 to 23 after the start of a period · [3]
| Range | What the source calls it |
|---|---|
| below 1.7 mIU/mL | No name given |
| 1.7 to 9.46 mIU/mL | "reference interval" |
| above 9.46 mIU/mL | No name given |
The 2.5th and 97.5th percentiles in 87 women. The median was 4.11 mIU/mL. See the follicular phase block for how the study was done [3].
Schüring and colleagues, 2016, Siemens Advia Centaur immunoassay, postmenopausal women
Postmenopausal women aged 49 to 66 · [3]
| Range | What the source calls it |
|---|---|
| below 44.6 mIU/mL | No name given |
| 44.6 to 167 mIU/mL | "reference interval" |
| above 167 mIU/mL | No name given |
The 2.5th and 97.5th percentiles in 103 blood donors with no periods for at least 12 months. The median was 87.1 mIU/mL. This lower limit is well above the 25.8 that MedlinePlus prints for women after menopause [3][2].
Schüring and colleagues, 2016, Siemens Immulite 2000XP immunoassay, follicular phase
Women aged 25 to 44 with regular cycles, follicular phase, days 3 to 5 after the start of a period · [3]
| Range | What the source calls it |
|---|---|
| below 3.75 mIU/mL | No name given |
| 3.75 to 14.2 mIU/mL | "reference interval" |
| above 14.2 mIU/mL | No name given |
The same 139 women's samples measured on a second platform in the same run. The median was 7.58 mIU/mL. See the Advia Centaur follicular phase block for how the study was done [3].
Schüring and colleagues, 2016, Siemens Immulite 2000XP immunoassay, luteal phase
Women aged 25 to 44 with regular cycles, luteal phase, days 21 to 23 after the start of a period · [3]
| Range | What the source calls it |
|---|---|
| below 1.66 mIU/mL | No name given |
| 1.66 to 9.59 mIU/mL | "reference interval" |
| above 9.59 mIU/mL | No name given |
The same 87 women's samples measured on a second platform. The median was 4.07 mIU/mL [3].
Schüring and colleagues, 2016, Siemens Immulite 2000XP immunoassay, postmenopausal women
Postmenopausal women aged 49 to 66 · [3]
| Range | What the source calls it |
|---|---|
| below 39.3 mIU/mL | No name given |
| 39.3 to 159 mIU/mL | "reference interval" |
| above 159 mIU/mL | No name given |
The same 103 women's samples measured on a second platform. The median was 76.2 mIU/mL [3].
Stages of Reproductive Aging Workshop + 10 (STRAW + 10), 2012
Women in the menopausal transition, on a blood sample drawn on any day · [4]
| Range | What the source calls it |
|---|---|
| 25 or below mIU/mL | No name given |
| above 25 mIU/mL | No name given |
The workshop describes levels greater than 25 IU/L in a random blood draw as characteristic of the late menopausal transition, the stage marked by 60 days or more without a period. It states that the figure rests on current international pituitary standards, that empirical analyses are needed to confirm it, and that the appropriate value depends on the assay used. It treats FSH as a supportive criterion that is not required for staging. It notes that in this stage FSH is sometimes in the menopausal range and sometimes in the range of the earlier reproductive years [4].
ESHRE, ASRM, CRE WHiRL and IMS guideline on premature ovarian insufficiency, 2024
Women under 40 with irregular or absent periods for at least 4 months · [5]
| Range | What the source calls it |
|---|---|
| 25 or below mIU/mL | No name given |
| above 25 mIU/mL | "elevated" |
The guideline's diagnostic criteria are disordered menstrual cycles for at least 4 months together with an elevated FSH above 25 IU/L. It states that the test does not have to be timed to a day of the cycle, and that the test is repeated after 4 to 6 weeks when there is diagnostic uncertainty. Its previous edition asked for two raised results. It does not base the diagnosis on estradiol, and states that anti-Müllerian hormone is not the primary diagnostic test [5].
US National Library of Medicine, MedlinePlus, adult men
Adult males · [2]
| Range | What the source calls it |
|---|---|
| below 1.5 mIU/mL | No name given |
| 1.5 to 12.4 mIU/mL | "normal" |
| above 12.4 mIU/mL | No name given |
Printed as 1.5 to 12.4 mIU/mL (1.5 to 12.4 IU/L). It names no assay or age group [2].
Schüring and colleagues, 2016, Siemens Advia Centaur immunoassay, men
Men aged 20 to 68 · [3]
| Range | What the source calls it |
|---|---|
| below 1.32 mIU/mL | No name given |
| 1.32 to 9.18 mIU/mL | "reference interval" |
| above 9.18 mIU/mL | No name given |
The 2.5th and 97.5th percentiles in 220 blood donors who took no regular medication. The median was 3.30 mIU/mL. The maker's own interval, reprinted in the paper, was 1.4 to 18.1 [3].
Schüring and colleagues, 2016, Siemens Immulite 2000XP immunoassay, men
Men aged 20 to 68 · [3]
| Range | What the source calls it |
|---|---|
| below 1.23 mIU/mL | No name given |
| 1.23 to 10.5 mIU/mL | "reference interval" |
| above 10.5 mIU/mL | No name given |
The same 220 men's samples measured on a second platform. The median was 3.49 mIU/mL [3].
What has been shown to move it
Shown to lower it1
Lower testosterone and HDL cholesterol
Shown to lower testosterone and HDL cholesterol in healthy men, more at higher doses. Levels returned to baseline after stopping.
FSH and free testosterone fell at the highest dose.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- LGD-4033 lowered total testosterone, sex hormone-binding globulin, HDL cholesterol and triglycerides in a dose-dependent way. FSH and free testosterone fell at the highest dose. Levels returned to baseline after stopping [1]. The 2026 review reports suppression of testosterone, sex hormone-binding globulin and HDL cholesterol across randomized trials, with reversible rises in liver enzymes for some compounds [4].
- Population
- 76 healthy young men over 21 days and 5 weeks of follow-up [1]; trials summarized in a review [4].
- Sources
- [1], [4]
- Caveats
- Trial doses were lower and shorter than the stacked, unmonitored use the review describes [4].
Shown to raise it1
Testosterone in men: clomiphene
Shown to raise total testosterone in men with low testosterone, by about 274 ng/dL against placebo, in pooled trials of clomiphene or enclomiphene.
Compared with placebo [13]; testosterone gel [13]; human chorionic gonadotropin [13]; the same men before treatment [14]
The numbers and sources
- Effect
- Against placebo, clomiphene or enclomiphene raised total testosterone by 273.76 ng/dL (95% CI 191.87 to 355.66, I² 89%), LH by 4.66 IU/L and FSH by 4.59 IU/L. Total testosterone did not differ from testosterone gel. Levels were higher than with hCG alone [13]. Across 17 studies pooled in a second review, total testosterone rose during treatment (pooled estimate 2.60, 95% CI 1.82 to 3.38, unit not given in the abstract), along with free testosterone, LH, FSH, SHBG and estradiol. Symptom scores on the Androgen Deficiency in Aging Males questionnaire improved. Side effects were reported by fewer than 10% of study populations and no serious adverse events were reported [14].
- Population
- Men with functional hypogonadism in randomized trials [13]. 1,642 men with hypogonadism in 19 studies, 4 randomized and 15 observational, treated for 1.5 to 52 months [14].
- Sources
- [13], [14]
- Caveats
- The first review pooled clomiphene with enclomiphene and heterogeneity was high [13]. The second rests mostly on before-and-after observational studies [14]. Use in men is off-label in the US [1]. Neither abstract reports fractures, heart events or fertility.
Tested, and not shown to change it1
Polycystic ovary syndrome
Shown to raise progesterone and endometrial thickness in women with PCOS. These are hormone and ultrasound measures, not pregnancy rates.
Estradiol, SHBG and FSH did not differ.
The numbers and sources
- Effect
- Across 22 studies (2,515 women), NAC was associated with higher progesterone (SMD 0.95, 95% CI 0.13 to 1.77) and thicker endometrium (SMD 0.58, 95% CI 0.10 to 1.06) than placebo and other drugs. Estradiol, SHBG and FSH did not differ [7].
- Population
- Women with PCOS, compared with placebo, metformin or clomiphene [7].
- Sources
- [7]
- Caveats
- Hormone and ultrasound measures, not pregnancy or live birth rates. Comparators were mixed.
How it compares with the reference method
Mixed results1
Between assays and laboratories
Limited evidence: FSH immunoassays varied by under 12% on shared samples, while the upper limit US laboratories reported for men ran from 7.9 to 20.0.
The numbers and sources
- Compared with
- Other immunoassays measuring the same serum pools, and other laboratories' reference ranges
- Effect
- When 16 Italian laboratories measured 5 serum pools with five automated immunoassays and one radioimmunoassay, the variance for FSH was below 12%. Two assays read higher than the others and two lower, and reference ranges at the low end varied widely, even among laboratories using the same assay [15]. In a survey of 117 US laboratories, the upper limit of the reference range reported for men ran from 7.9 to 20.0. Seventy percent of the ranges came from checking the maker's package insert values, in 20 to 200 samples [16]. In one study the same women's follicular samples gave an interval of 4.07 to 12.9 mIU/mL on one platform and 3.75 to 14.2 on another [3].
- Population
- 16 laboratories [15]. 117 US laboratories [16]. 139 women [3].
- Sources
- [15], [16], [3], [8]
- Caveats
- The survey's abstract gives no unit for its limits [16]. The American Society for Reproductive Medicine states that correlation among FSH assays is high but absolute values can differ [8].
Did not match the reference method1
One cycle to the next
Limited evidence: early-cycle FSH in the same woman differed by up to about 4.4 mIU/mL in either direction between two cycles.
The numbers and sources
- Compared with
- The same woman's early follicular FSH in another cycle
- Effect
- In 100 women tested in the early follicular phase of two cycles, the limits of agreement for FSH were +4.36 and -4.52 IU/L. Its range of variation was 1.29 times its own mean, against 0.48 for the antral follicle count [13]. In 85 women tested in up to four cycles, the variance of basal FSH differed between cycles by a ratio of 2.44, and a large variation from cycle to cycle went with lower ovarian reserve [14]. The American Society for Reproductive Medicine states that FSH has significant variability between and within cycles, which limits the reliability of a single measurement [8].
- Population
- 100 women having two cycles of assisted reproduction [13]. 85 regularly menstruating women aged 18 to 39 [14].
- Sources
- [13], [14], [8]
- Caveats
- Both studies enrolled women having fertility treatment. A result from a woman who still has periods cannot be placed against a phase range without knowing the cycle day.
What studies tie it to
Linked in research2
Sperm production in men seen for infertility
Limited evidence: in men seen for infertility, higher FSH went with abnormal sperm counts, and FSH above 7.6 mIU/mL went with azoospermia caused by failed sperm production.
The numbers and sources
- Effect
- Among 153 men with no sperm in the ejaculate, 89% of those whose testicles were not producing sperm had FSH greater than 7.6 mIU/mL or a testicular long axis of 4.6 cm or less. Of the men with a blockage, 96% had FSH of 7.6 or less or a long axis greater than 4.6 cm. FSH alone separated the two groups with an area under the curve of 0.87 [10]. In men seen at one infertility clinic, FSH above 7.5 IU/L carried a five to thirteen times higher risk of abnormal semen quality than FSH below 2.8 IU/L, depending on the semen measure. The authors report a raised risk of abnormal sperm concentration and shape above 4.5 IU/L, a level inside their laboratory's reference range of 1.4 to 18.1 IU/L [11].
- Population
- 153 azoospermic men evaluated from 1995 to 2000 [10]. 610 men at one urology infertility clinic from 2004 to 2008, of whom 153 were excluded [11].
- Sources
- [10], [11]
- Caveats
- Both studies are of men already being seen for infertility at single centers, so the cut points may not hold for men in general. Neither sets a reference interval.
Bone loss across the menopausal transition
One cohort found FSH levels and their change over 4 years predicted spine and hip bone loss through the menopausal transition, while estradiol changes did not.
The numbers and sources
- Effect
- Over 4 years, lumbar spine bone density fell 5.6% in women who reached natural postmenopause and 3.2% in late perimenopause. Baseline FSH, later FSH and their interaction predicted the loss. With a baseline FSH below 25 mIU/mL, a follow-up FSH above 70 predicted a 4-year spine loss of 0.05 g/cm2. Estradiol below 35 pg/mL went with lower bone density, but yearly estradiol changes did not predict loss [12].
- Population
- 2,311 premenopausal or early perimenopausal women at five sites of the Study of Women's Health Across the Nation, examined yearly for five visits [12].
- Sources
- [12]
- Caveats
- Observational, from one cohort. FSH rises as ovarian function declines, so it may mark the stage of the transition and not act on bone itself.
Mixed results1
Response to ovarian stimulation in IVF
Mixed results: raised early-cycle FSH is described as specific but not sensitive for low ovarian reserve, and no ovarian reserve test predicted ongoing pregnancy after IVF.
The numbers and sources
- Effect
- The American Society for Reproductive Medicine describes an elevated basal FSH, measured on day 2, 3 or 4 of the cycle, as a specific but not sensitive test for diminished ovarian reserve [8]. A meta-analysis of individual data from studies of FSH, anti-Müllerian hormone and antral follicle count before IVF found that age alone predicted a poor response with an area under the curve of 0.61, and that anti-Müllerian hormone or the follicle count alone reached 0.78 and 0.76. For ongoing pregnancy, age was the single predictor (0.57) and none of the tests added to it [9].
- Population
- 28 study databases with 5,705 women undergoing IVF [9].
- Sources
- [8], [9]
- Caveats
- The pooled analysis does not report in its abstract how FSH alone performed for a poor response. The committee opinion gives no FSH cut point [8].
Checked, no link found2
Natural conception in women without infertility
Limited evidence: in two cohorts early-cycle FSH did not predict natural conception, including FSH above 10 mIU/mL in women aged 30 to 44.
The numbers and sources
- Effect
- In women aged 30 to 44 who had been trying to conceive for 3 months or less, those with early follicular FSH above 10 mIU/mL had a predicted probability of conceiving of 63% by 6 cycles (95% CI 50% to 73%) against 62% (57% to 66%) in women with normal values, and 82% against 75% by 12 cycles. Neither difference was significant [6]. In 102 women planning pregnancy and followed for a year, basal FSH did not predict time to ongoing pregnancy once age was accounted for (hazard ratio 0.96, 95% CI 0.86 to 1.06) [7].
- Population
- 750 women aged 30 to 44 without a history of infertility, 83 of them with FSH above 10 mIU/mL [6]. 102 women planning pregnancy [7].
- Sources
- [6], [7], [8]
- Caveats
- Observational. Both cohorts enrolled women with no known infertility, so they do not describe women already having trouble conceiving. The American Society for Reproductive Medicine states that markers of ovarian reserve are poor predictors of reproductive potential independently of age [8].
Endometriosis
One small study in a Cochrane review found no difference in FSH or LH between women with and without endometriosis.
The numbers and sources
- Effect
- A Cochrane review of blood tests for endometriosis found one study in which FSH and LH did not differ significantly between women with endometriosis confirmed at surgery and women without it. The reviewers describe this as consistent with other studies of hormones in endometriosis and did not recommend further study of these hormones as diagnostic markers [17].
- Population
- 49 participants in one study [17].
- Sources
- [17]
- Caveats
- One small study, which could miss a modest difference. The review rated all its included studies as of poor methodological quality [17].
Sources
- US Food and Drug Administration. 21 CFR 862.1300, Follicle-stimulating hormone test system. Electronic Code of Federal Regulations. https://www.ecfr.gov/current/title-21/section-862.1300
- US National Library of Medicine. Follicle-stimulating hormone (FSH) blood test. MedlinePlus Medical Encyclopedia. Reviewed August 18, 2025. https://medlineplus.gov/ency/article/003710.htm
- Schüring AN, Kelsch R, Pierściński G, Nofer JR. Establishing Reference Intervals for Sex Hormones on the Analytical Platforms Advia Centaur and Immulite 2000XP. Annals of Laboratory Medicine. 2016. https://doi.org/10.3343/alm.2016.36.1.55
- Harlow SD, Gass M, Hall JE, et al. Executive Summary of the Stages of Reproductive Aging Workshop + 10: Addressing the Unfinished Agenda of Staging Reproductive Aging. The Journal of Clinical Endocrinology and Metabolism. 2012. https://doi.org/10.1210/jc.2011-3362
- Panay N, Anderson RA, Bennie A, et al. Evidence-based guideline: premature ovarian insufficiency. Human Reproduction Open. 2024. https://doi.org/10.1093/hropen/hoae065
- Steiner AZ, Pritchard D, Stanczyk FZ, et al. Association Between Biomarkers of Ovarian Reserve and Infertility Among Older Women of Reproductive Age. JAMA. 2017. https://doi.org/10.1001/jama.2017.14588
- Depmann M, Broer SL, Eijkemans MJC, et al. Anti-Müllerian hormone does not predict time to pregnancy: results of a prospective cohort study. Gynecological Endocrinology. 2017. https://doi.org/10.1080/09513590.2017.1306848
- Practice Committee of the American Society for Reproductive Medicine. Testing and interpreting measures of ovarian reserve: a committee opinion. Fertility and Sterility. 2020. https://doi.org/10.1016/j.fertnstert.2020.09.134
- Broer SL, van Disseldorp J, Broeze KA, et al. Added value of ovarian reserve testing on patient characteristics in the prediction of ovarian response and ongoing pregnancy: an individual patient data approach. Human Reproduction Update. 2013. https://doi.org/10.1093/humupd/dms041
- Schoor RA, Elhanbly S, Niederberger CS, Ross LS. The role of testicular biopsy in the modern management of male infertility. Journal of Urology. 2002. https://doi.org/10.1016/s0022-5347(05)65411-0
- Gordetsky J, van Wijngaarden E, O'Brien J. Redefining abnormal follicle-stimulating hormone in the male infertility population. BJU International. 2012. https://doi.org/10.1111/j.1464-410x.2011.10783.x
- Sowers MR, Jannausch M, McConnell D, et al. Hormone Predictors of Bone Mineral Density Changes during the Menopausal Transition. The Journal of Clinical Endocrinology and Metabolism. 2006. https://doi.org/10.1210/jc.2005-1836
- Jayaprakasan K, Campbell B, Hopkisson J, et al. Establishing the intercycle variability of three-dimensional ultrasonographic predictors of ovarian reserve. Fertility and Sterility. 2008. https://doi.org/10.1016/j.fertnstert.2007.10.028
- Kwee J, Schats R, McDonnell J, et al. Intercycle variability of ovarian reserve tests: results of a prospective randomized study. Human Reproduction. 2004. https://doi.org/10.1093/humrep/deh119
- Radicioni A, Lenzi A, Spaziani M, et al. A multicenter evaluation of immunoassays for follicle-stimulating hormone, luteinizing hormone and testosterone: Concordance, imprecision and reference values. Journal of Endocrinological Investigation. 2013. https://doi.org/10.1007/bf03347112
- Grimstad F, Le M, Zganjar A, et al. An Evaluation of Reported Follicle-stimulating Hormone, Luteinizing Hormone, Estradiol, and Prolactin Reference Ranges in the United States. Urology. 2018. https://doi.org/10.1016/j.urology.2018.07.024
- Nisenblat V, Bossuyt PM, Shaikh R, et al. Blood biomarkers for the non-invasive diagnosis of endometriosis. Cochrane Database of Systematic Reviews. 2016. https://doi.org/10.1002/14651858.cd012179