🌸 PCOS Workup

What this panel can settle, and by what logic

Ten markers doing two jobs at once, and the second job is the one worth the money. The first is to establish biochemical hyperandrogenism, which is one of the three diagnostic features. The second is to remove the four conditions that reproduce the whole picture, because polycystic ovary syndrome is a diagnosis reached after those are gone Joham 2025.

1. Total Testosterone with Free Testosterone and SHBG (Sex Hormone-Binding Globulin). The pooled diagnostic accuracy across 18 studies and 2,857 women put total testosterone at an area under the curve of 0.87 and calculated free testosterone at 0.85, with DHEA-sulfate trailing at 0.77 Bizuneh 2024. Low SHBG is the mechanism rather than an extra finding: it raises the free fraction while the total stays inside the printed interval.
2. 17-OH Progesterone removes a different disease. Non-classic congenital adrenal hyperplasia presents with the same irregular cycles and the same hirsutism, and 17-OH progesterone is the marker that detects the enzyme block behind it Sarafoglou 2023. This is the single most valuable exclusion on the list and the one most panels omit.
3. Prolactin and TSH (Thyroid-Stimulating Hormone) remove two more. Hyperprolactinemia and thyroid disease both produce anovulatory cycles, both are treatable in weeks, and both cost under $10 here.
4. Fasting Insulin with HbA1c (Hemoglobin A1c) is the part that changes management rather than the label. Hyperinsulinemia suppresses SHBG and raises free androgen, so treating it moves the androgens without touching an androgen.

LH & FSH and Estradiol, Sensitive (LC/MS-MS) are here to exclude ovarian insufficiency, not to confirm PCOS — see below for why the ratio is the most over-read number on this panel.

What it cannot settle, and what would

It cannot diagnose PCOS, and no blood panel can. The current framework requires two of three features: hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology or an elevated AMH Joham 2025 Piltonen 2024. Blood reaches the first. A bleeding history reaches the second. The third is a transvaginal ultrasound or an Anti-Müllerian Hormone (AMH), and this panel contains neither, so a woman with regular cycles and a normal free testosterone has not excluded anything by buying it.

The LH to FSH ratio is not a diagnostic criterion and never was. It appears in none of the three features Joham 2025. Where the ratio does carry information is the other way round: in an observational series of functional hypothalamic amenorrhea, 81.5% of women sat at or below 1.0 and only 2.2% reached 2.1 or above Boegl 2024. A low ratio in a lean woman with no periods is a finding about energy availability. A high one is not a diagnosis.

It cannot measure insulin resistance, only correlate with it. Fasting insulin has no reference method and no agreed threshold, and HbA1c (Hemoglobin A1c) is as much a red cell measurement as a glucose one — anything that shortens red cell survival lowers it independently of glycemia Chen 2022. Both are useful trends. Neither is a clamp.

And it cannot exclude the rare causes it is often bought to exclude. An androgen-secreting ovarian or adrenal tumor and Cushing's syndrome both present with rapid virilization, and the tests for them are imaging and a cortisol protocol, not a single morning androgen panel Joham 2025. Rapid onset over months, rather than years, is the feature that should send you past this page.

Draw conditions that decide whether the money is wasted

This panel has three different correct draw days, and which one applies to you depends on something the order form does not ask.

1. If you still bleed on a recognizable schedule: days 2 to 5. LH & FSH and Estradiol, Sensitive (LC/MS-MS) are only interpretable against an early-follicular interval, and a rising follicular estradiol suppresses FSH, so a day-10 draw can hide a diminished reserve behind a normal-looking number Casals 2023.
2. If your periods are absent or wildly irregular: draw any day, and write the date of your last bleed on the form. There is no day 3 in a cycle that does not happen, and waiting for one is how women defer this test for a year. The caveat is that Estradiol, Sensitive (LC/MS-MS) then has no reference phase attached, so it is read as a level rather than as a cycle position.
3. Either way, 17-OH Progesterone before 9am and not in the second half of a cycle. The corpus luteum secretes 17-OH progesterone as well as the adrenal does, so a luteal sample crosses follicular thresholds without any enzyme block behind it, and those thresholds are assay-specific to begin with Sarafoglou 2023. This is the single most expensive timing error on the panel because it invents a diagnosis rather than missing one.
4. Fast 9 to 12 hours, and do not train hard the day before. The Fasting Insulin is the marker most panels skip and the one this page is built on; a fed sample makes it uninterpretable, and a hard session the previous evening lowers it in a way that flatters the result.

How you would know it answered your question, and what each pattern means next

Six patterns. Where a retest interval appears, it is set by the biology that has to change, not by convenience.

• High Free Testosterone, low SHBG (Sex Hormone-Binding Globulin), irregular cycles, normal 17-OH Progesterone: two of the three features are met on history plus bloods. The missing piece is imaging or an Anti-Müllerian Hormone (AMH), and that is the next purchase rather than another androgen panel Piltonen 2024.
• Raised 17-OH Progesterone on a follicular morning draw: stop treating this as PCOS. It needs confirmation and usually an ACTH stimulation test, and the management of a 21-hydroxylase block is not the management of PCOS Sarafoglou 2023.
• Raised Prolactin: repeat it rested and ask for a macroprolactin screen before any pituitary imaging is booked, because roughly a fifth of hyperprolactinemia is the inactive antibody-bound complex Sharma 2021.
• Low LH & FSH with low Estradiol, Sensitive (LC/MS-MS) in a lean or heavily training woman: this is the opposite diagnosis. Functional hypothalamic amenorrhea sits at a ratio of 1.0 or below in more than four in five cases Boegl 2024, and it is treated with food and rest rather than with an anti-androgen.
• Normal androgens, high Fasting Insulin: treat the insulin and redraw insulin, SHBG and free testosterone at 12 to 16 weeks. SHBG is made in the liver and responds over months; a 6-week recheck reads the old set point.
• A high FSH with a low estradiol under 40: leave this page. That combination is a premature ovarian insufficiency question and it has its own guideline and its own follow-up Panay 2024.

Sources read for these sections

• Joham AE, et al. Approach to the Patient: Diagnostic Challenges in the Work Up for Polycystic Ovary Syndrome. Journal of Clinical Endocrinology and Metabolism 2025 · PMID 39836632
• Piltonen TT, et al. Utility of Serum Anti-Mullerian Hormone Measurement as Part of Polycystic Ovary Syndrome Diagnosis. Seminars in Reproductive Medicine 2024 · PMID 38776986
• Bizuneh AD, et al. Evaluating the diagnostic accuracy of androgen measurement in polycystic ovary syndrome: a systematic review and diagnostic meta-analysis to inform evidence-based guidelines. Human Reproduction Update 2024 · PMID 39305127
• Sarafoglou K, et al. Interpretation of Steroid Biomarkers in 21-Hydroxylase Deficiency and Their Use in Disease Management. Journal of Clinical Endocrinology and Metabolism 2023 · PMID 36950738
• Boegl M, et al. The LH:FSH Ratio in Functional Hypothalamic Amenorrhea: An Observational Study. Journal of Clinical Medicine 2024 · PMID 38592037
• Sharma LK, et al. Prevalence of Macroprolactinemia in People Detected to Have Hyperprolactinemia. Journal of Laboratory Physicians 2021 · PMID 34975255
• Casals G, et al. Recommendations for the measurement of sexual steroids in clinical practice. A position statement of SEQCML/SEEN/SEEP. Advances in Laboratory Medicine 2023 · PMID 37359897
• Chen Z, et al. Interpretation of HbA1c lies at the intersection of analytical methodology, clinical biochemistry and hematology (Review). Experimental and Therapeutic Medicine 2022 · PMID 36382101
• Panay N, et al. Evidence-based guideline: premature ovarian insufficiency. Human Reproduction Open 2024 · PMID 39660328