Does hyperprolactinemia cause elevated androgen levels in women?

Hyperprolactinemia Does Not Directly Cause Elevated Androgens in Women—It Causes Hypogonadism

Hyperprolactinemia primarily causes hypogonadism (low estrogen) in women, not hyperandrogenism. However, there is a well-documented but indirect association where elevated prolactin can increase adrenal androgen production, specifically DHEA-S, through a synergistic effect with ACTH on the adrenal glands 1.

The Paradox: Hypogonadism vs. Androgen Elevation

The Endocrine Society guidelines 2 clearly establish that prolactinomas cause hypogonadism with decreased gonadal steroids, leading to amenorrhea, galactorrhea, sexual dysfunction, and decreased bone density 2. This is the dominant clinical picture—not hyperandrogenism.

However, research reveals a more nuanced relationship:

Adrenal Androgen Elevation (DHEA-S)

• Prolactin has a direct synergistic effect with ACTH on adrenal cells to increase DHEA and DHEA-S secretion, but not androstenedione or cortisol 1
• This occurs through partial inhibition of adrenal 3β-hydroxysteroid dehydrogenase 1
• Approximately 40% of hyperprolactinemic women show some androgenic abnormality, with elevated DHEA-S found in 19-21% 3
• Strong correlations exist between serum prolactin and DHEA-S levels (γ = 0.48, P < 0.05) 1
• This effect is reversible: DHEA-S levels normalize when prolactin is controlled with cabergoline or surgical treatment 4, 5

Free Testosterone Elevation

• Elevated free testosterone is the most characteristic androgenic abnormality (abnormal in 43% of hyperprolactinemic women) 3
• This occurs despite normal or even low total testosterone levels 3
• The mechanism is decreased TEBG (testosterone-estradiol-binding globulin) levels—about one-third lower in hyperprolactinemic women 3
• Free testosterone correlates directly with insulin resistance in these patients 6

Clinical Algorithm

When evaluating a hyperprolactinemic woman with apparent hyperandrogenism:

1. Measure specific androgens: Check DHEA-S, free testosterone, total testosterone, and androstenedione

   • Elevated DHEA-S alone suggests prolactin-mediated adrenal stimulation
   • Elevated free testosterone with normal total testosterone suggests low TEBG
   • Elevated androstenedione or total testosterone suggests alternative diagnosis (PCOS, adrenal tumor)

2. Assess gonadal status: Measure estradiol

   • Hypogonadic (E2 < 30 pg/mL): Classic prolactinoma presentation
   • Eugonadic (E2 > 30 pg/mL): Hyperandrogenism may be contributing to menstrual dysfunction 7

3. Treat the hyperprolactinemia first with cabergoline 2

   • If DHEA-S and free testosterone normalize with prolactin control, the association is confirmed 4, 5
   • If androgens remain elevated, investigate alternative causes

Critical Caveats

• This is ACTH-dependent: The androgenic effects require normal HPA function. Patients with impaired HPA have very low DHEA-S that doesn't change despite prolactin normalization 4
• Dexamethasone suppression normalizes the androgens, confirming ACTH dependency 3
• Don't confuse this with PCOS: While both can present with menstrual irregularities and hyperandrogenism, the patterns differ. Prolactin-associated androgen elevation primarily affects DHEA-S and free testosterone (via low TEBG), not androstenedione 3, 1
• The effect requires time: Acute prolactin elevation doesn't immediately raise DHEA-S; chronic hyperprolactinemia is needed 1

Bottom Line for Practice

Hyperprolactinemia causes hypogonadism as its primary reproductive effect. The androgen elevation seen in some patients is a secondary phenomenon involving adrenal DHEA-S production and altered testosterone binding, not true ovarian hyperandrogenism. Treating the prolactinoma with cabergoline normalizes both prolactin and androgens 4, 5, confirming this is a reversible consequence of hyperprolactinemia rather than a separate pathologic process requiring additional treatment.