SERMs (PCT)SERMSelective estrogen receptor modulator: it either activates or blocks the estrogen receptor depending on the tissue.
Nolvadex vs Clomid vs Enclomiphene
The table compares the compounds’ key data from their entry pages. Open each compound’s full entry for details. Educational content, not medical advice.
 Nolvadex (Tamoxifen) | Clomid (Clomiphene Citrate) | Enclomiphene (Androxal) | |
|---|---|---|---|
| What it is | Tamoxifen citrate, 1962 ICI Pharmaceuticals synthesis, FDA-approved (1977) for ER+ breast cancer. The AAS-PCT golden-standard SERM: pituitary ER-α blockade → LH/FSH disinhibition → endogenous testosterone recovery. 60+ years of clinical literature. | Clomiphene citrate, Merrell 1956 synthesis, FDA-approved (1967) for female infertility (ovulatory dysfunction). Racemic mixture (~62% zuclomiphene estrogenic + ~38% enclomiphene antiestrogenic). The latter is the PCT-active half. Off-label male hypogonadism + AAS-PCT secondary-standard SERM. | Pure trans-isomer of clomiphene – Repros Therapeutics 2014-2016 Phase III hypogonadism candidate. Cleaner SERM profile than Clomid (zuclomiphene-free), BUT FDA CRL 2016 → not approved. Available via US-compounding + EU research-pharm. |
| MechanismMechanism of actionThe molecular pathway by which a compound acts in the body (e.g. which receptor or enzyme it binds). | Non-steroidal SERM, ER-α competitive antagonist at pituitary + breast | Non-steroidal SERM, racemic mixture (62% zuclo + 38% enclo) | Pure trans-isomer clomiphene, ER-α antagonist at pituitary, NO zuclomiphene mood effect |
| Dosing (PCT) | 20-40 mg/day, 4-6 weeks | 50 mg/day × 1-2 weeks, then 25 mg/day × 2-4 weeks | — |
| Half-lifeHalf-lifeThe time for the compound’s plasma concentration to fall by half; indicates how fast it clears and how often it is dosed. | ~5-7 days (parent) / ~14 days (4-OH-tamoxifen active metabolite) | Zuclomiphene ~5-7 weeks accumulating / enclomiphene ~5 days | ~5 days (cleaner than Clomid mixed t1/2) |
| OnsetOnsetThe time from dosing until a measurable effect appears. | LH rise within 24-72 h, Test recovery 2-3 weeks | LH rise 5-10 days, Test recovery 3-4 weeks | LH rise 24-72 h, Test recovery 2-4 weeks |
| Legal statusLegal / WADA statusThe compound’s regulatory status (e.g. prescription) and its place on the WADA prohibited-in-sport list. | FDA + EMA Rx, registered in HU + PL, WADA S4 (banned in-competition) | FDA + EMA Rx (female indication), off-label male hypogonadism, WADA S4 (banned) | NOT FDA-approved (CRL 2016), US-compounding + EU research-pharm + UGL |
| Dosing (PCT or hypogonadism) | — | — | 12.5-25 mg/day, morning |
| Full entry | Open → | Open → | Open → |
What it is
Nolvadex (Tamoxifen)Tamoxifen citrate, 1962 ICI Pharmaceuticals synthesis, FDA-approved (1977) for ER+ breast cancer. The AAS-PCT golden-standard SERM: pituitary ER-α blockade → LH/FSH disinhibition → endogenous testosterone recovery. 60+ years of clinical literature.
Clomid (Clomiphene Citrate)Clomiphene citrate, Merrell 1956 synthesis, FDA-approved (1967) for female infertility (ovulatory dysfunction). Racemic mixture (~62% zuclomiphene estrogenic + ~38% enclomiphene antiestrogenic). The latter is the PCT-active half. Off-label male hypogonadism + AAS-PCT secondary-standard SERM.
Enclomiphene (Androxal)Pure trans-isomer of clomiphene – Repros Therapeutics 2014-2016 Phase III hypogonadism candidate. Cleaner SERM profile than Clomid (zuclomiphene-free), BUT FDA CRL 2016 → not approved. Available via US-compounding + EU research-pharm.
MechanismMechanism of actionThe molecular pathway by which a compound acts in the body (e.g. which receptor or enzyme it binds).
Nolvadex (Tamoxifen)Non-steroidal SERM, ER-α competitive antagonist at pituitary + breast
Clomid (Clomiphene Citrate)Non-steroidal SERM, racemic mixture (62% zuclo + 38% enclo)
Enclomiphene (Androxal)Pure trans-isomer clomiphene, ER-α antagonist at pituitary, NO zuclomiphene mood effect
Dosing (PCT)
Nolvadex (Tamoxifen)20-40 mg/day, 4-6 weeks
Clomid (Clomiphene Citrate)50 mg/day × 1-2 weeks, then 25 mg/day × 2-4 weeks
Enclomiphene (Androxal)—
Half-lifeHalf-lifeThe time for the compound’s plasma concentration to fall by half; indicates how fast it clears and how often it is dosed.
Nolvadex (Tamoxifen)~5-7 days (parent) / ~14 days (4-OH-tamoxifen active metabolite)
Clomid (Clomiphene Citrate)Zuclomiphene ~5-7 weeks accumulating / enclomiphene ~5 days
Enclomiphene (Androxal)~5 days (cleaner than Clomid mixed t1/2)
OnsetOnsetThe time from dosing until a measurable effect appears.
Nolvadex (Tamoxifen)LH rise within 24-72 h, Test recovery 2-3 weeks
Clomid (Clomiphene Citrate)LH rise 5-10 days, Test recovery 3-4 weeks
Enclomiphene (Androxal)LH rise 24-72 h, Test recovery 2-4 weeks
Legal statusLegal / WADA statusThe compound’s regulatory status (e.g. prescription) and its place on the WADA prohibited-in-sport list.
Nolvadex (Tamoxifen)FDA + EMA Rx, registered in HU + PL, WADA S4 (banned in-competition)
Clomid (Clomiphene Citrate)FDA + EMA Rx (female indication), off-label male hypogonadism, WADA S4 (banned)
Enclomiphene (Androxal)NOT FDA-approved (CRL 2016), US-compounding + EU research-pharm + UGL
Dosing (PCT or hypogonadism)
Nolvadex (Tamoxifen)—
Clomid (Clomiphene Citrate)—
Enclomiphene (Androxal)12.5-25 mg/day, morning