Aromatase
The enzyme that converts androgens to oestrogens.
Aromatase (CYP19A1) is a cytochrome P450 enzyme that converts androgens to oestrogens — testosterone to oestradiol, androstenedione to oestrone. It's expressed in adipose tissue, brain, bone, gonads, and placenta. In men, peripheral aromatase activity (especially in adipose tissue) is the primary source of circulating oestradiol. Aromatase inhibitors (anastrozole, letrozole, exemestane) suppress this conversion and are used clinically in oestrogen-receptor-positive breast cancer. In men's-health research-context, aromatase inhibitor use during testosterone-replacement therapy is increasingly discouraged — the literature shows over-suppression of oestradiol produces worse outcomes than mild elevation.
- BiomarkerEstradiol high (male)
Elevated estradiol in men frequently accompanies higher testosterone or testosterone-replacement therapy via aromatase activity. What the research literature shows on healthy ranges and when it crosses into a problem.
- BiomarkerEstradiol low (male)
Estradiol below ~20 pg/mL in men is consistently associated in research literature with worse bone, libido, lipid, and cognitive endpoints — including in TRT users on aromatase inhibitors.
- BiomarkerDHEA-S 80 µg/dL
Dehydroepiandrosterone sulphate at 80 µg/dL in a man in his 40s is below the typical age-matched range. What DHEA-S measures, why the literature treats it as a global endocrine marker, and what its decline means.
- GlossaryGLP-1
Glucagon-like peptide-1, an incretin hormone that regulates glucose and appetite.
- GlossaryGIP
Glucose-dependent insulinotropic polypeptide, an incretin hormone with metabolic and adipose effects.