Anastrozole vs Enclomiphene
Two prescription drugs used off-label by men to raise testosterone through completely different mechanisms — one blocks estrogen conversion, the other stimulates the brain's own signal to the testes.
Anastrozole
Arimidex
An approved aromatase inhibitor for breast cancer, used off-label in men to raise testosterone by blocking its conversion to estrogen — a real endocrine effect, but off-label use in men who are not on TRT risks pushing estrogen too low, with real bone-density and lipid consequences.
Full Anastrozole evidence reviewEnclomiphene
Randomized Phase III data: restores a man's own testosterone while preserving sperm — but never FDA-approved for men, and compounded.
Full Enclomiphene evidence reviewSide by side
| Anastrozole | Enclomiphene | |
|---|---|---|
| Marketed for | Breast cancer (approved); off-label testosterone/estrogen management in men | Raising testosterone, preserving fertility |
| Evidence grade | FDA-approved | Clinical data |
| Family | Hormonal | Hormonal |
| Key human source | Aromatase inhibition in elderly men RCT, JCEM 2004 | Phase III RCT, BJU Int 2016 |
marks a row where the two differ. Evidence grades come from our evidence matrix, which grades each molecule on the human data for the use it is marketed for.
Our verdict
Enclomiphene has real Phase 3 data specifically for its off-label use: it raises a man's own testosterone while preserving sperm production and fertility, though it has never been FDA-approved for men and is compounded. Anastrozole is FDA-approved, but for breast cancer — its off-label male use lowers estrogen by blocking aromatase, which can raise free testosterone indirectly but risks pushing estrogen too low, with real consequences for bone density and lipids. They aren't interchangeable: enclomiphene raises testosterone directly, anastrozole only reshapes the testosterone-to-estrogen ratio.
Anastrozole fits if
Estrogen is already elevated (common on TRT) and the goal is rebalancing the ratio, ideally with bloodwork guiding the dose to avoid crashing estrogen.
Enclomiphene fits if
Raising your own testosterone while preserving fertility is the actual goal — this is the drug with trial data for exactly that use, not a repurposed cancer drug.
Where to get it
Where to get testosterone therapy
Testosterone and hormone-optimization telehealth services with clinician oversight and lab work. Confirm current pricing and lab requirements — and whether Anastrozole fits your case — with the provider.
