From the Guidelines
For hirsutism evaluation, I recommend drawing total testosterone (TT) and free testosterone (FT) as the first-line laboratory tests to assess biochemical hyperandrogenism, as supported by the most recent and highest quality study 1. These tests should be drawn in the early morning during the follicular phase of the menstrual cycle (days 3-8) for most accurate results. Additional tests that may be considered include:
- Dehydroepiandrosterone sulfate (DHEAS) and androstenedione (A4), although they have poorer specificity 1
- Thyroid-stimulating hormone (TSH) to rule out thyroid disease 1
- Prolactin to rule out hyperprolactinemia 1
- A comprehensive metabolic panel including fasting glucose and lipid profile to assess for diabetes and dyslipidemia 1
- A luteinizing hormone (LH) to follicle-stimulating hormone (FSH) ratio to evaluate for polycystic ovary syndrome (PCOS) If PCOS is suspected, consider adding hemoglobin A1c or glucose tolerance testing. For patients with irregular periods, adding a serum pregnancy test and endometrial assessment may be appropriate. These laboratory tests help identify the underlying cause of hirsutism, whether it's PCOS (the most common cause), congenital adrenal hyperplasia, Cushing's syndrome, androgen-secreting tumors, or other endocrine disorders. The pattern of hormone abnormalities guides treatment decisions, which may include oral contraceptives, anti-androgens like spironolactone, or specific therapies for identified endocrine disorders. It is essential to use highly accurate laboratory methods, such as mass spectrometry, to measure androgen levels, as direct androgen immunoassays have limited accuracy 1.
From the Research
Laboratory Tests for Hirsutism
To diagnose and manage hirsutism, several laboratory tests can be drawn, including:
- DHEA-S (dehydroepiandrosterone sulfate) 2
- Total free testosterone determinations 2
- 17-hydroxyprogesterone 2, 3
- Prolactin 2
- Compound S (serum 11-deoxycortisol) 2
- Cortisol measurements 2, 3
- Dexamethasone suppression test 2
- Serum testosterone level 4
- FSH (follicle-stimulating hormone) 3
- LH (luteinizing hormone) 3
- Estradiol 3
- Progesterone 3
- Sex hormone-binding globulin (SHBG) 3
- Dehydroepiandrosterone (DHEA) 3
- Dehydroepiandrosterone sulphate (DHEAS) 3
- 17 hydroxyprogesterone (17 OH Pg) 3
- Total and free T3, T4, TSH, TBG, Plasma Cortisol transcortin 3
Rationale for Laboratory Tests
These laboratory tests help to:
- Confirm the presence of hirsutism and exclude associated or etiological abnormalities and disorders 5
- Identify the underlying etiology of hirsutism, such as polycystic ovarian syndrome, idiopathic hirsutism, or other causes 6, 4
- Detect patients at risk for infertility, diabetes, cardiovascular disease, and endometrial carcinoma 6
- Guide treatment decisions, including hormonal suppression, peripheral androgen blockade, and cosmetic treatments 5, 2, 4