Which PCOS blood tests to request
The 2023 International Evidence-based Guideline for polycystic ovary syndrome, developed by an international network of professional societies and patient groups, sets out the blood tests. For the diagnosis: total testosterone and a measure of free testosterone such as the free androgen index, with DHEA-S and androstenedione if those are normal. To exclude other causes: TSH, prolactin and 17-hydroxyprogesterone. For long-term health: a glucose test and a lipid profile at diagnosis.
| Marker | Why it matters | What a result suggests | On SiPhox |
|---|---|---|---|
| Total testosterone | First-line test for biochemical androgen excess | Above the female range supports PCOS; very high values need a check for tumors | Longevity (men), Hormone Focus, Ultimate 360, GLP (men) |
| Free testosterone or FAI | Catches androgen excess that total testosterone misses | High free T or FAI with normal total T is still biochemical hyperandrogenism | Longevity (men), Hormone Focus, Ultimate 360, GLP |
| SHBG | Needed to calculate FAI; often low with insulin resistance | Low SHBG raises free testosterone | Longevity (men), Thyroid Focus, Hormone Focus, Ultimate 360, GLP |
| DHEA-S | Second-line androgen if testosterone is normal | Raised values support androgen excess; very high values need prompt review | Longevity, Hormone Focus, Ultimate 360 |
| Androstenedione | Second-line androgen | Adds sensitivity when testosterone is normal | Not on SiPhox |
| AMH | Allowed in adults in place of an ultrasound for ovarian morphology | High AMH supports polycystic ovaries; not used alone or in teens | Not on SiPhox |
| TSH | Thyroid disease causes irregular cycles | Abnormal TSH points to a thyroid cause | Longevity, Heart & Metabolic, Thyroid Focus, Ultimate 360, GLP |
| Prolactin | High prolactin stops ovulation | Raised values need repeating and a cause | Hormone Focus, Ultimate 360 |
| 17-hydroxyprogesterone | Screens for non-classic congenital adrenal hyperplasia | Raised values need an endocrinologist | Not on SiPhox |
| FSH, LH, estradiol | Rule out ovarian failure and hypothalamic causes | High FSH or very low estradiol suggests another diagnosis | Longevity (women), Hormone Focus, Ultimate 360 |
| HbA1c or glucose | PCOS raises type 2 diabetes risk | 5.7% to 6.4% is prediabetes; the guideline prefers an oral glucose tolerance test for higher-risk women | Longevity, Heart & Metabolic, Ultimate 360, GLP |
| Triglycerides, HDL, LDL | Guideline lipid profile at diagnosis | High triglycerides and low HDL fit insulin resistance | Longevity, Heart & Metabolic, Thyroid Focus, Ultimate 360, GLP |
How PCOS is diagnosed
In adults, the 2023 guideline keeps the Rotterdam rule: PCOS needs two of three features, after other causes are excluded.
- Androgen excess, either clinical (excess hair growth, acne, scalp thinning) or on a blood test.
- Ovulatory dysfunction, usually irregular cycles.
- Polycystic ovarian morphology, on ultrasound or, new in 2023, a raised AMH in adults.
So a blood test alone rarely makes the diagnosis; it confirms androgen excess, excludes look-alikes and measures metabolic risk. If you have irregular cycles and obvious clinical androgen excess, you may already meet two criteria before any test. The guideline says a normal testosterone does not rule out PCOS when the clinical signs are there, and it asks labs to use tandem mass spectrometry (LC-MS/MS) rather than direct immunoassays, which it says have limited accuracy for the low testosterone levels seen in women.
The metabolic side is not optional. The guideline recommends checking glycemic status at diagnosis and every one to three years after, and a lipid profile at diagnosis, because insulin resistance is common in PCOS whatever your weight.
Teenagers are different. In adolescents the guideline requires both irregular cycles and androgen excess, and it advises against using ultrasound or AMH within eight years of the first period, because many healthy teens have multi-follicular ovaries and irregular cycles. That makes the androgen blood tests more important in younger patients, and it is why an at-home panel should be read by a clinician who knows the age-specific rules.
Our prediabetes blood test guide explains the A1C, fasting glucose and OGTT cut-offs, and our insulin resistance test guide covers fasting insulin and HOMA-IR.
PCOS markers by SiPhox panel
Our count from SiPhox's published panel lists (checked 29 Sep 2026) against the 14 markers in the table above, counting only markers reported for women. No SiPhox panel carries androstenedione, AMH or 17-OHP.
The gap to notice: Hormone Focus has the androgens, LH, FSH and prolactin but no TSH, HbA1c or lipids, while Longevity Essentials has TSH, HbA1c and lipids but, for women, no testosterone or SHBG. Ultimate 360 is the only panel with both halves.
Worked example: irregular cycles and acne at 27
Illustrative numbers. A 27-year-old has cycles 45 to 60 days apart and adult acne. Her at-home results:
| Marker | Result | Reading |
|---|---|---|
| Total testosterone | 68 ng/dL (2.36 nmol/L) | Above many labs' female range |
| SHBG | 22 nmol/L | Low-normal |
| Free androgen index | 10.7 | 2.36 x 100 / 22; raised |
| Prolactin, TSH | Normal | Two look-alikes less likely |
| HbA1c | 5.8% | Prediabetes range (5.7% to 6.4%) |
| Triglycerides / HDL | 165 / 44 mg/dL | Pattern that fits insulin resistance |
She has two of three criteria (irregular cycles and biochemical androgen excess), which fits PCOS, but a clinician still has to exclude non-classic CAH with a 17-OHP test and confirm the pattern. The HbA1c in the prediabetes range is the most important finding for her long-term health: the guideline favors an oral glucose tolerance test to confirm, and lifestyle and medical options exist. Converting testosterone: ng/dL x 0.0347 = nmol/L; our lab unit converter does it for you.
Timing and preparation for a PCOS blood test
- The combined pill changes androgens and SHBG. The guideline says androgen results are very hard to read on the combined oral contraceptive pill, and that if testing is essential the pill should be stopped for at least three months, with another form of contraception meanwhile. Do not stop the pill without talking to your prescriber.
- Test in the morning, ideally early in the cycle if you have periods (days 2 to 5), so FSH, LH and estradiol can be compared with standard ranges.
- Fasting helps if glucose or insulin are measured; HbA1c does not need it.
- Tell the lab about biotin and supplements such as inositol; the FDA warns biotin can distort hormone tests.
What an at-home test can and cannot do for PCOS
- Measure testosterone, FAI, SHBG, DHEA-S, LH, FSH and prolactin
- Check HbA1c and lipids every year or two, as the guideline asks
- Track androgens and A1C during treatment
- Diagnose PCOS: a diagnosis needs a clinician and exclusion of other causes
- Measure AMH, 17-OHP or androstenedione, or do an ultrasound
- Run an oral glucose tolerance test
Best-fit SiPhox panel for PCOS
| If you want | Test | Choose |
|---|---|---|
| Hormones and metabolic risk in one draw | Testosterone, FAI, SHBG, DHEA-S, LH, FSH, prolactin, TSH, HbA1c, lipids | Ultimate 360 |
| The androgen workup only | Testosterone, FAI, SHBG, DHEA-S, LH, FSH, prolactin, progesterone | Hormone Focus |
| Yearly metabolic follow-up | HbA1c, C-peptide, lipids, ApoB, TG:HDL ratio, TSH | Longevity Essentials |
| AMH, 17-OHP, OGTT or ultrasound | Venous labs and imaging | Your doctor |
Ultimate 360 costs $249 plus $25 shipping. The budget route is Hormone Focus ($124) for the androgen picture, then Longevity Essentials on your next test for HbA1c, lipids and TSH, which adds up to $298 with shipping across two tests versus $274 for one Ultimate 360.
Ultimate 360
Everything on the four core panels plus iron studies, B12 and folate, GGT and PSA.
Check price
Hormone Focus
Sex hormones for men and women, including PSA for men and progesterone for women.
Check price
Longevity Essentials
The default panel: heart, metabolic, hormone and inflammation markers in one draw.
Check price
Frequently asked questions
What blood tests diagnose PCOS?
No blood test diagnoses PCOS alone. Total and free testosterone (or the free androgen index) show androgen excess, AMH can stand in for an ultrasound in adults, and TSH, prolactin and 17-OHP rule out look-alikes. A clinician puts it together with your cycle history.
Can you have PCOS with normal testosterone?
Yes. PCOS needs two of three features, so irregular cycles plus clinical signs such as excess hair growth, or polycystic ovaries, are enough even when testosterone is normal.
Is the LH:FSH ratio used to diagnose PCOS?
No. A raised LH:FSH ratio is common in PCOS but it is not one of the diagnostic criteria in the 2023 international guideline.
Should women with PCOS be tested for diabetes?
Yes. The 2023 guideline recommends checking glycemic status at diagnosis and every one to three years, with an oral glucose tolerance test preferred for higher-risk women, plus a lipid profile at diagnosis.
Can I test for PCOS at home?
You can measure the hormones and metabolic markers at home, including testosterone, FAI, SHBG, DHEA-S, LH, FSH, prolactin and HbA1c. The diagnosis still needs a clinician.
Sources
- Teede HJ et al. Recommendations from the 2023 international evidence-based guideline for the assessment and management of PCOS. Fertil Steril 2023
- Teede HJ et al. Recommendations from the 2023 international evidence-based guideline for the assessment and management of PCOS (recommendations 1.2.3, 1.2.4 and 1.2.6). J Clin Endocrinol Metab 2023, full text
- MedlinePlus: Testosterone levels test
- MedlinePlus: Anti-Mullerian hormone test
- MedlinePlus: Follicle-stimulating hormone (FSH) levels test
- MedlinePlus: Luteinizing hormone (LH) levels test
- MedlinePlus: TSH (thyroid-stimulating hormone) test
- NIDDK (NIH): Diabetes tests and diagnosis
- MedlinePlus: Insulin in blood
- MedlinePlus: Cholesterol levels
- FDA: Biotin interference with lab tests
- SiPhox Health: Hormone Focus panel (checked 29 Sep 2026)
- SiPhox Health: Longevity Essentials panel and add-ons (checked 29 Sep 2026)
- SiPhox Health: Ultimate 360 panel (checked 29 Sep 2026)