Symptom → lab tests
Which blood tests are used for irregular periods?
Short answer
Irregular or missed periods are evaluated with the hormones that run the cycle — FSH, LH, estradiol and progesterone — plus prolactin, TSH and androgens (testosterone, DHEA-S), which cover the common disruptors: PCOS, thyroid disease, high prolactin and perimenopause. Timing the draw to your cycle matters and is noted below.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
When should you see a clinician instead of ordering a test?
- Very heavy bleeding (soaking a pad an hour for several hours), bleeding with dizziness or fainting — seek care
- Missed periods with a positive or possible pregnancy and pelvic pain — seek care promptly
Why these tests for irregular periods?
The ratio of LH to FSH and the androgen levels point toward PCOS; a high FSH with low estradiol suggests diminished ovarian reserve or menopause transition; high prolactin and thyroid disease each disrupt ovulation and are easy to miss without testing. Pregnancy is always excluded first.
Which conditions do these tests help evaluate?
- PCOS — Androgens, LH/FSH, insulin and thyroid markers to investigate PCOS.
- Perimenopause — Estradiol, FSH, LH and thyroid to make sense of changing cycles and symptoms.
- Thyroid Problems — TSH, Free T4/T3 and antibodies to evaluate an under- or over-active thyroid.
Which tests, and what do they cost?
Prices are cash-pay; every order adds one $6 lab processing fee. Physician authorization is included; no insurance or referral needed.
| Test or panel | Type | Price | Fasting | Results |
|---|---|---|---|---|
| Women's Hormone PanelSaves $129.90 vs ordering the tests separately | Panel · 11 tests | $239.99 | No | 3–5 business days |
| Women's Fertility EssentialsSaves $89.96 vs ordering the tests separately | Panel · 5 tests | $119.99 | No | 3–5 business days |
| Menopause Assessment PanelSaves $92.93 vs ordering the tests separately | Panel · 8 tests | $179.99 | No | 2–4 business days |
| FSH (Follicle Stimulating Hormone) | Test | $29.99 | No | 2–4 business days |
| LH (Luteinizing Hormone) | Test | $36.99 | No | 1–3 business days |
| Estradiol (E2) | Test | $35.99 | No | 1–3 business days |
| Progesterone | Test | $31.99 | No | 1–3 business days |
| Prolactin | Test | $39.99 | No | 2–4 business days |
| TSH (Thyroid Stimulating Hormone) | Test | $26.99 | No | 1–3 business days |
| Testosterone, Free & Total | Test · 2 biomarkers | $54.99 | No | 3–5 business days |
| DHEA-Sulfate | Test | $32.99 | No | 1–3 business days |
Common questions
What day of my cycle should I test?
FSH, LH and estradiol are usually drawn on cycle days 2–5; progesterone about 7 days after ovulation (day 21 of a 28-day cycle). If cycles are absent or very irregular, any day works and your clinician interprets accordingly.
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.