Clomiphene / Enclomiphene

Clomiphene (brand names Clomid, Serophene) is best known for triggering ovulation in women trying to conceive, by blocking estrogen feedback at the brain and raising the hormones (LH and FSH) that drive ovulation or testosterone production. It's a small-molecule oral drug, not a peptide. It's FDA-approved for that ovulation-induction use in women; use in men to raise testosterone is off-label. Enclomiphene, one of clomiphene's two isomers, is not FDA-approved for any use (its bid for approval in male hypogonadism was rejected by the FDA in 2015) and is available in the US only through compounding pharmacies.

Clomiphene is used for female infertility and studied off-label in men to raise testosterone by stimulating the body's own hormone signaling; it's FDA-approved for the female-infertility use. A 2022 meta-analysis in men found testosterone rose during clomiphene treatment (along with free testosterone, LH, FSH, SHBG and estradiol), with side effects in fewer than 10% and no serious adverse events, though most included studies were observational. A Phase 2 trial found enclomiphene raised testosterone similarly to testosterone gel while preserving sperm production, but the FDA did not approve it for the male indication, and a 2026 meta-analysis found no significant testosterone difference between clomiphene and testosterone gel.

Clomiphene citrate is FDA-approved as Clomid (NDA 016131, originally approved February 1, 1967, sponsored by William S. Merrell Company) and Serophene for ovulation induction in anovulatory or oligo-ovulatory women desiring pregnancy.[¹] The FDA-approved indication is exclusively in women — clomiphene is not FDA-approved for any male indication and is not approved for treatment of male hypogonadism. Enclomiphene (the trans-isomer alone) is not FDA-approved for any indication. Repros Therapeutics' Androxal NDA for enclomiphene in secondary male hypogonadism received a Complete Response Letter in December 2015 citing comparator-arm design and bioanalytical method validation concerns; the planned November 2015 FDA advisory committee meeting was canceled before convening. Repros (later rebranded Androclus Therapeutics) did not resubmit; enclomiphene drug-development was discontinued for all medical purposes by 2021.[²] Off-label use of clomiphene in men with hypogonadism, infertility, or as a TRT alternative is widespread but operates outside FDA approval and outside major men's-health professional-society guidelines (Endocrine Society Bhasin 2018 hypogonadism guidelines, AUA Mulhall 2018). Generic clomiphene has been widely available since the 1980s; multiple generic manufacturers supply tablets. Not DEA-scheduled. WADA-banned in regulated sport — clomifene (INN spelling) is explicitly named under Section S4.2 (Anti-Estrogenic Substances [Anti-Estrogens and Selective Estrogen Receptor Modulators (SERMs)]) of the 2026 Prohibited List as a Specified Substance. Enclomiphene is not separately named in S4.2 but is covered as a stereoisomer of clomiphene under WADA's general framework.[⁶]

Clomiphene is prescription-only and FDA-approved only for female ovulation induction; enclomiphene is not FDA-approved and available only via compounding; both are banned in WADA-tested sport, and visual changes are a recognized reason to stop and seek evaluation. VialWise is a research and educational reference, not medical advice — consult a licensed professional.

⚠️ For research and educational purposes only. Clomiphene citrate (Clomid) is FDA-approved exclusively for ovulation induction in anovulatory women — not for any male indication. Enclomiphene (the trans-isomer alone) is not FDA-approved for any indication; the Repros Therapeutics Androxal NDA for secondary male hypogonadism received a Complete Response Letter in December 2015 and development was discontinued by 2021. Use of either compound in men — for hypogonadism, infertility, or as a TRT alternative — is off-label and operates outside FDA approval. Information in this entry is informational, not medical advice. Always consult appropriate professional guidance before any protocol decisions.

⚠️ Clomiphene and enclomiphene are not peptides. This entry exists in the Vialwise library because researchers running TRT-adjacent men's-health protocols frequently use clomiphene or enclomiphene as a TRT alternative (raises endogenous testosterone via hypothalamic-pituitary axis stimulation) or as a fertility-preserving option (preserves spermatogenesis, unlike exogenous testosterone administration). Both compounds are small-molecule triphenylethylene-class selective estrogen receptor modulators (SERMs) — not peptides, not proteins, not injectables. Both are taken as oral tablets (clomiphene: FDA-label tablets, generic widely available; enclomiphene: only available via 503A compounding pharmacies as a single-isomer formulation, typically or capsules). Mechanistically, pharmacologically, and regulatorily they sit in a different category from the rest of the Vialwise library.

⚠️ The Vialwise calculator is informational, not computational, for clomiphene and enclomiphene. Same framing as the [anastrozole.md](./anastrozole.md) entry — these are oral compounds dosed as whole or split tablets, with no per-injection draw to compute. The calculator's role for clomiphene/enclomiphene is to display the FDA-label and off-label dosing patterns plus the clomiphene-vs-enclomiphene disambiguation and pill-splitting precision considerations.

⚠️ Clomiphene citrate is a racemic mixture of two stereoisomers with substantially different pharmacology — they are not equivalent. This is the most important single piece of information in this entry. Commercial clomiphene citrate (Clomid, Serophene, generic) contains: - Enclomiphene (the trans-isomer, ~62% of commercial clomiphene; USP range 50–70%) — the "active" anti-estrogen. Half-life ~8–10 hours. Peak plasma concentration at ~4 hours. Acts as a relatively pure estrogen-receptor antagonist. Cleared rapidly. This is the isomer that produces the desired hypothalamic-anti-estrogen effect. - Zuclomiphene (the cis-isomer, ~38% of commercial clomiphene; USP range 30–50%) — half-life >40 hours, with tissue half-life of several days to a week. Weakly estrogenic (mixed agonist/antagonist with net agonist character at some receptor subtypes). Accumulates substantially with long-term dosing. After prolonged clomiphene use, zuclomiphene predominates in serum — the long-half-life isomer accumulates while the short-half-life enclomiphene clears. The clinical implication is meaningful: long-term clomiphene therapy in men effectively becomes long-term zuclomiphene exposure with intermittent enclomiphene peaks. Enclomiphene-only formulations were developed (Androxal) to deliver pure anti-estrogen activity without the accumulating estrogenic zuclomiphene component. The Androxal phase II/III trials demonstrated enclomiphene alone produced testosterone elevation similar to topical testosterone gel while preserving spermatogenesis.[⁷] Despite the regulatory failure (Complete Response Letter 2015, development discontinued 2021), enclomiphene-only formulations are now available via 503A compounding pharmacies for off-label men's-health use. Researchers selecting between racemic clomiphene and enclomiphene-only formulations are choosing on the zuclomiphene-accumulation question.

⚠️ Distinctive US regulatory category for enclomiphene — "FDA-rejected for the male hypogonadism indication; never-FDA-approved for any indication; available via 503A compounding only." Enclomiphene's regulatory history is unusually pointed for a research-community compound: Repros Therapeutics specifically attempted to advance enclomiphene through the FDA approval process for the male hypogonadism indication; the company completed two Phase 3 trials (ZA-301, ZA-302); the FDA canceled the November 2015 advisory committee meeting before it convened due to bioanalytical method validation concerns; the FDA issued a Complete Response Letter in December 2015 citing inadequate Phase 3 study design (active-comparator vs placebo-controlled trial requirements) and recommending additional Phase 3 trials; Repros did not resubmit; the company rebranded as Androclus Therapeutics and eventually wound down the program. Enclomiphene's failure to gain FDA approval was not for safety reasons — the safety profile in the Repros trials was favorable — but for adequacy-of-clinical-benefit-demonstration reasons under FDA's regulatory framework.[²] This is a regulatory category not previously represented in the library: a compound with a substantial Phase 3 development program that was specifically rejected by the FDA for the indication of interest, and that researchers continue to use off-label via 503A compounding.

⚠️ WADA-banned in regulated sport — clomifene (INN spelling) explicitly named under Section S4.2 as a Specified Substance. The 2026 WADA Prohibited List Section S4.2 (Anti-Estrogenic Substances [Anti-Estrogens and SERMs]) explicitly names "Clomifene" alongside Bazedoxifene, Elacestrant, Raloxifene, Fulvestrant, Tamoxifen, Cyclofenil, Ospemifene, and Toremifene.[⁶] Note that WADA uses the INN spelling "Clomifene" while the US adopted name is "Clomiphene" — these are the same compound. Enclomiphene is not separately named in S4.2 but is covered as a stereoisomer of clomiphene under WADA's general framework prohibiting stereoisomers and analogues of named substances. Both are Specified Substances per the S4 section header (Specified Substance status means a positive test triggers a reduced sanction range vs non-Specified Substances). Prohibited at all times — in-competition and out-of-competition. This is the second S4 listing in the Vialwise library after Anastrozole (S4.1 Aromatase Inhibitors); Clomiphene/Enclomiphene's S4.2 listing alongside Tamoxifen anchors the SERM cluster of future entries.

Clomiphene citrate is a triphenylethylene-class selective estrogen receptor modulator (SERM) developed in the 1950s and 1960s by William S. Merrell Company. The compound was FDA-approved on February 1, 1967 under NDA 016131 for ovulation induction in anovulatory or oligo-ovulatory women desiring pregnancy.[¹] The 1967 FDA annual report characterized clomiphene's approval as "a significant new drug approval." The World Health Organization includes clomiphene on its List of Essential Medicines as the sole "ovulation inducer."

Mechanism. Clomiphene's primary mechanism is competitive estrogen-receptor antagonism at the hypothalamus. By blocking estrogen-receptor-mediated negative feedback of circulating estradiol on hypothalamic GnRH-secreting neurons, clomiphene produces a sustained increase in pulsatile GnRH release, which in turn raises pituitary LH and FSH secretion. In women, the increased LH and FSH support follicular development and trigger ovulation in anovulatory cycles. In men, the increased LH stimulates Leydig cell testosterone production while increased FSH supports spermatogenesis — making clomiphene mechanistically distinct from exogenous testosterone administration (which suppresses LH/FSH and impairs spermatogenesis through HPG-axis negative feedback).

The racemic-mixture problem. This is the load-bearing technical detail of clomiphene's pharmacology. Commercial clomiphene citrate is a racemic mixture of two stereoisomers with substantially different pharmacology:

- Enclomiphene (the trans-isomer) — comprises ~62% of commercial clomiphene by weight (USP range 50–70%). Acts as a relatively pure estrogen-receptor antagonist. Plasma half-life ~8–10 hours. This is the "active SERM" component that produces the desired hypothalamic-anti-estrogen effect. - Zuclomiphene (the cis-isomer) — comprises ~38% of commercial clomiphene by weight (USP range 30–50%). Has mixed agonist/antagonist activity at estrogen receptors with net partial-agonist character. Plasma half-life >40 hours; tissue half-life of several days to a week. Accumulates substantially with long-term dosing. After prolonged clomiphene therapy, zuclomiphene predominates in serum.

The clinical implication: long-term clomiphene therapy in men effectively becomes long-term zuclomiphene exposure with intermittent enclomiphene peaks. Whether the accumulating zuclomiphene component meaningfully detracts from the intended effect (or contributes to side effects like mood, vision changes, or gynecomastia in men) is contested in the men's-health literature — but the pharmacology is unambiguous about the long-term accumulation.

Enclomiphene-only formulations. Repros Therapeutics developed Androxal (enclomiphene citrate) as a single-isomer formulation specifically for the male secondary hypogonadism indication. The development program included multiple Phase II dose-ranging studies (ZA-203, ZA-204) and two Phase III trials (ZA-301, ZA-302) under designation ZA-203. Phase II trial results published by Wiehle et al. 2014 in *Fertility and Sterility* demonstrated that enclomiphene or daily produced morning serum testosterone elevation similar to topical testosterone gel while preserving spermatogenesis (LH and FSH preserved or elevated, sperm counts maintained).[⁷]

Enclomiphene's FDA regulatory history (the rejection). Repros Therapeutics submitted an NDA for Androxal in 2014 for the indication of secondary hypogonadism in overweight men wishing to restore normal testicular function. The FDA scheduled an advisory committee meeting for November 3, 2015 to review the NDA. The advisory committee meeting was canceled before convening due to FDA concerns about bioanalytical method validation that could affect interpretability of pivotal study data.[²] In December 2015, the FDA issued a Complete Response Letter (not an outright rejection) citing: (a) inadequate Phase 3 study design — the FDA's primary concern was that the active comparator (topical testosterone gel) had been studied as a co-primary endpoint, and the agency required a placebo-controlled trial; (b) study entry criteria concerns; (c) titration concerns; (d) bioanalytical method validation. The FDA recommended Repros conduct an additional Phase 3 study or studies. Repros did not resubmit. The company rebranded as Androclus Therapeutics and eventually wound down the enclomiphene program. As of 2021, enclomiphene drug-development is discontinued for all medical purposes. Enclomiphene-only formulations are now available exclusively via 503A compounding pharmacies for off-label men's-health use.

Off-label use in men — published evidence base. Off-label use of clomiphene (and increasingly enclomiphene from compounding pharmacies) in men is widespread despite the absence of FDA approval. The published evidence in men is substantial, with the 2022 Huijben systematic review and meta-analysis (*Andrology*) consolidating the data:

- Huijben et al. 2022 systematic review and meta-analysis of clomiphene citrate for male hypogonadism (PMID 34933414): 19 studies, 1,642 patients (4 RCTs + 15 observational); meta-analysis on 17 studies, 1,279 patients. Reported an increase in total testosterone during clomiphene treatment (standardized mean difference 2.60, 95% CI 1.82–3.38), with increases also reported in free testosterone, LH, FSH, SHBG, and estradiol. Side effects in <10% of populations; no serious adverse events reported.[³] The strongest single citation establishing clomiphene's effectiveness for men's hypogonadism. Important framing caveat: 15 of the 19 included studies are observational/single-arm, so the pooled estimate is a pre-treatment-vs-during-treatment comparison, not a placebo-controlled difference. - Krzastek et al. 2019 Long-Term Safety and Efficacy retrospective review (PMID 31216250, *Journal of Urology*): 400 patients across two institutions, 2010–2018, mean follow-up 25.5 ± 20.48 months (range 0–84), with 280 receiving clomiphene ≤3 years and 120 receiving it for >3 years.[⁴] Strongest long-term safety citation. - Wiehle et al. 2014 Phase II RCT comparing enclomiphene to topical testosterone gel (PMID 25044085, *Fertility and Sterility*).[⁷] - Constantinou et al. 2026 systematic review and meta-analysis directly comparing clomiphene citrate with testosterone replacement therapy (PMID 42435198, *European Journal of Clinical Pharmacology*): 11 studies, 1,512 patients (764 clomiphene vs 748 TRT). Reported no significant difference in serum testosterone between clomiphene and testosterone gel (mean difference 6.64 ng/dL, not significant); injectable testosterone produced higher serum testosterone than clomiphene, and TRT was associated with greater libido improvement.[⁸] The newest head-to-head-framed comparison; complements Huijben 2022. - Kim et al. 2026 predictors-of-response analysis (PMID 42251758, *Journal of Sexual Medicine*): 292 men, LC-MS/MS testosterone assay, using the every-other-day starting pattern escalated every other day — the same pattern described in this entry's Dosing Protocol; 47% of the cohort met the response threshold.[¹⁰] Recent real-world corroboration of the dosing pattern and of the fact that a substantial share of users do not reach target. - Shabsigh et al. 2005 (PMID 16422830) and related studies establishing the clomiphene starting-dose pattern as the most common research-community starting dose.[⁵]

The professional-guidance landscape is beginning to move (2026). The major men's-health guidelines that this entry references (Endocrine Society, Bhasin 2018; AUA, Mulhall 2018) do not recommend SERMs as routine testosterone-replacement alternatives, and that remains the guideline position. However, in February 2026 the British Society for Sexual Medicine published a position statement specifically on the potential use of enclomiphene in male hypogonadism (*World Journal of Men's Health*, PMID 41714894) — the first professional-society position statement addressing enclomiphene directly.[¹¹] A position statement is not an approval and does not change enclomiphene's US regulatory status (still not FDA-approved, still compounded-only); it is noted here because the entry's "no professional-society guidance exists" framing is no longer strictly accurate.

Common research interests. Despite the off-label status (clomiphene) and never-approved status (enclomiphene), both compounds are widely used in research-community contexts: - TRT alternative — primary off-label men's-health use case. Researchers seeking to raise endogenous testosterone without exogenous T administration (typically motivated by fertility preservation, simpler administration, or a preference for endogenous production over external supplementation). The Huijben 2022 meta-analysis supports this use case.[³] - Fertility-preserving adjunct during or after TRT. Researchers on TRT who want to maintain or restore spermatogenesis use clomiphene or enclomiphene to keep LH/FSH-driven testicular function active. Often co-administered with HCG. See [hcg.md](./hcg.md). - HPG-axis recovery after androgen cycles. "Post-cycle therapy" (PCT) protocols in research-community supraphysiologic-testosterone contexts use clomiphene to accelerate HPG-axis recovery after exogenous androgen suppression. This is outside any FDA-approved indication and still outside the published RCT literature — but it is no longer outside the published literature entirely: Bandura et al. 2026 (*Andrology*, PMID 42387872) is a narrative review specifically of off-label clomiphene in post-cycle therapy after anabolic-androgenic steroid use, covering the proposed mechanisms, the reported efficacy signals, and the diagnostic challenges of assessing endocrine recovery (including the value of LC-MS/MS assays and the enclomiphene-isomer question).[⁹] A narrative review is not trial evidence — the rationale for PCT use remains primarily mechanistic. - Female ovulation induction (FDA-approved use). Clomiphene's actual FDA indication. Clinical use under specialist supervision; not relevant to research-community men's-health use cases but is the regulatory anchor for the compound's existence. - Off-label male infertility. Clomiphene for subfertile hypogonadal men is a related but distinct off-label use case — overlapping with the TRT-alternative use case but motivated specifically by fertility rather than testosterone replacement.

Commonly reported

• Hot flashes — most common patient-reported side effect (~10% in trials)
• Abdominal discomfort, bloating — common in female patients due to ovarian effects
• Breast tenderness
• Headache, mood symptoms (irritability, depression, anxiety) — class effect
• Visual disturbances — a notable distinct side effect for clomiphene specifically. Reported as blurring, scintillating scotomata, light sensitivity, or other visual symptoms in approximately 1–2% of patients on FDA-label dosing. Mechanism: clomiphene crosses the blood-retinal barrier and has been associated with retinal effects. Visual changes warrant prompt discontinuation and evaluation. Reported visual changes have generally resolved on discontinuation.
• Nausea, vomiting (uncommon)
• Multiple gestations (twins, higher-order) — relevant in the female ovulation induction context, ~5–10% rate of multiple pregnancies in clinical use; not relevant to off-label men's-health use
• Ovarian hyperstimulation syndrome — relevant in female patients on higher doses; not relevant to off-label men's-health use
• Mood symptoms — most-cited side effect in the off-label men's-health context. Commonly reported as irritability, mood swings, or low mood. Has been observed at lower rates with enclomiphene-only formulations compared to racemic clomiphene, possibly due to the absence of accumulating zuclomiphene.
• Visual disturbances — same as the female-indication context; reported in <5% of off-label men's-health use; warrants prompt discontinuation and evaluation
• Gynecomastia — uncommon but reported; possibly related to the zuclomiphene component's weak estrogenic activity in long-term clomiphene use
• Headache, fatigue — uncommon
• Decreased libido or erectile difficulty — paradoxical given the testosterone elevation; reported in a small minority of men on clomiphene; possibly related to zuclomiphene-mediated estrogenic activity at central sites
• Hot flashes — same as the female-indication context; uncommon at off-label men's-health doses
• No consistent pattern of serious adverse events in the published men's-health literature; the Huijben 2022 meta-analysis reported side effects in <10% of populations and no serious adverse events.[³] The Krzastek 2019 long-term study (mean 25.5 months follow-up, range 0–84 months) similarly reported no serious adverse events.[⁴]
• Long-term safety in men beyond 7+ years is not well characterized. Krzastek 2019's longest follow-up was 84 months (7 years). Researchers using clomiphene continuously over decades-long durations should be explicit with themselves about this gap.
• Zuclomiphene accumulation effects — the long-half-life cis-isomer accumulates with sustained dosing, raising theoretical concern about cumulative estrogenic exposure over multi-year use. This is the principal mechanistic argument for preferring enclomiphene-only formulations for sustained off-label use.
• Bone density — not well characterized for clomiphene in men over multi-year exposure. SERM-class theoretical concern; periodic DEXA monitoring is appropriate for sustained use.
• Cardiovascular effects — not well characterized in long-term off-label men's-health use.

Pregnancy — Pregnancy Category X. Anti-estrogenic and embryo-fetal toxicity concerns. Documented absence of pregnancy required before initiating in female patients.

Liver disease or history of liver dysfunction

Abnormal uterine bleeding of undetermined origin (female patients)

Ovarian cysts (other than polycystic ovary syndrome) (female patients)

Hypersensitivity to clomiphene or any product excipient

Uncontrolled thyroid or adrenal dysfunction

Organic intracranial lesions (e.g., pituitary tumor)

Visual disturbances — discontinue immediately for any visual changes; evaluate before considering re-treatment.

Long-term off-label men's-health use is outside the FDA-approved 6-cycle maximum framework. Researchers using clomiphene continuously for years are operating outside the FDA-approved duration framework as well as the FDA-approved indication.

Ovarian hyperstimulation syndrome (female patients) — particularly at higher doses or in patients with PCOS.

Multiple pregnancies (female patients) — increased rate of twins and higher-order multiples.

Regulatory note (US — clomiphene): FDA-approved exclusively for female ovulation induction (Clomid 1967, NDA 016131). All use in men is off-label. Generic widely available since the 1980s. Standard prescription required (not DEA-scheduled).

Regulatory note (US — enclomiphene): Not FDA-approved for any indication. Repros Therapeutics' Androxal NDA received a Complete Response Letter in December 2015; development discontinued by 2021.[²] Available exclusively via 503A compounding pharmacies for off-label men's-health use.

Regulatory note (sport): WADA-banned in regulated sport. Clomifene (INN spelling) is explicitly named under Section S4.2 of the 2026 Prohibited List as a Specified Substance.[⁶] Enclomiphene is covered as a stereoisomer of clomiphene under WADA's general framework. Both prohibited at all times.

Not DEA-scheduled.

Not subject to the 503A bulks list controversy that affected several research peptides — clomiphene is FDA-approved (off-label use only is at issue) and enclomiphene is a small-molecule SERM with established pharmacology.

SERM

Selective estrogen receptor modulator; a drug that blocks estrogen receptors in some tissues while acting estrogen-like in others.

Off-label use

Use of an approved drug for a condition or population not listed on its FDA-approved label.

Testosterone

The principal male sex hormone, important for sexual development, muscle and bone, and other functions.

Compounding pharmacy

a pharmacy that prepares a medication to order under a prescription.

1. Sanofi-Aventis (originally William S. Merrell Company). Clomid (clomiphene citrate) tablets prescribing information. US Food and Drug Administration. NDA 016131, originally approved February 1, 1967. Most recent label revision (s026) accessible at accessdata.fda.gov/drugsatfda_docs/label/2012/016131s026lbl.pdf. FDA nda review at accessdata.fda.gov/drugsatfda_docs/nda/2012/016131Orig1s026.pdf. Source for: daily × 5 days FDA-approved dose for female ovulation induction; daily × 5 days second-cycle dose; 6-cycle maximum recommended duration; contraindications (pregnancy Category X, liver disease, ovarian cysts other than PCOS, hypersensitivity, uncontrolled thyroid/adrenal dysfunction, organic intracranial lesions); side-effect profile (visual disturbances, hot flashes, abdominal discomfort, mood symptoms, ovarian hyperstimulation syndrome, multiple gestations). Clomid was sponsored by William S. Merrell Company at original approval; current labeling is held by Sanofi-Aventis. Multiple generic versions also available since the 1980s.
2. Repros Therapeutics (later Androclus Therapeutics). Enclomiphene citrate (Androxal) NDA Complete Response Letter regulatory chain. SEC 8-K filings: November 2015 advisory committee cancellation announcement at sec.gov/Archives/edgar/data/897075/000117184315005822/newsrelease.htm; December 2015 Complete Response Letter announcement at sec.gov/Archives/edgar/data/897075/000117184315006596/newsrelease.htm. Source for: Repros Therapeutics' Androxal NDA submission for secondary hypogonadism in overweight men; the November 3, 2015 advisory committee meeting cancellation due to bioanalytical method validation concerns; the December 2015 Complete Response Letter citing inadequate Phase 3 study design (active-comparator vs placebo-controlled trial requirements), study entry criteria concerns, titration concerns, and bioanalytical method validation; FDA's recommendation that Repros conduct additional Phase 3 studies; Repros' subsequent decision not to resubmit; eventual program discontinuation by 2021. This is the canonical regulatory citation for the entry's "FDA-rejected for the male hypogonadism indication" framing.
3. Huijben M, Lock MTWT, de Kemp VF, de Kort LMO, van Breda HMK. (2022). Clomiphene citrate for men with hypogonadism: a systematic review and meta-analysis. Andrology, 10(3):451–469.(PMID 34933414)
4. Krzastek SC, Sharma D, Abdullah N, Sultan M, Machen GL, Wenzel JL, Ells A, Chen X, Kavoussi M, Costabile RA, Smith RP, Kavoussi PK. (2019). Long-Term Safety and Efficacy of Clomiphene Citrate for the Treatment of Hypogonadism. Journal of Urology, 202(5):1029–1035 (November 2019).(PMID 31216250)
5. Shabsigh A, Kang Y, Shabsigh R, Gonzalez M, Liberson G, Fisch H, Goluboff E. (2005). Clomiphene Citrate Effects on Testosterone/Estrogen Ratio in Male Hypogonadism. The Journal of Sexual Medicine, 2(5):716–721 (September 2005).(PMID 16422830)
6. World Anti-Doping Agency. The 2026 Prohibited List, International Standard (effective 1 January 2026). Canonical PDF: wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf (linked from the WADA landing page; local archival copy in `docs/legal/wada-2026-prohibited-list.pdf`). Clomifene (INN spelling; US adopted name "Clomiphene") is named explicitly under Section S4.2 (Anti-Estrogenic Substances [Anti-Estrogens and Selective Estrogen Receptor Modulators (SERMs)]) — page 10 of the canonical PDF — as a Specified Substance. Verbatim from the canonical PDF: under S4.2 ("anti-estrogenic substances [anti-estrogens and selective estrogen receptor modulators (SERMS)], Including, but not limited to:"), the named compounds are Bazedoxifene, Elacestrant, Raloxifene, Clomifene, Fulvestrant, Tamoxifen, Cyclofenil, Ospemifene, and Toremifene. The S4 section header notes "Prohibited substances in classes S4.1 and S4.2 are Specified Substances." Enclomiphene is not separately named in S4.2 but is covered as a stereoisomer of clomiphene under WADA's general framework prohibiting stereoisomers and structural analogues of named substances. Prohibited at all times, in-competition and out-of-competition.
7. Wiehle RD, Fontenot GK, Wike J, Hsu K, Nydell J, Lipshultz L; ZA-203 Clinical Study Group. (2014). Enclomiphene citrate stimulates testosterone production while preventing oligospermia: a randomized phase II clinical trial comparing topical testosterone. Fertility and Sterility, 102(3):720–727 (September 2014, online July 17, 2014).(PMID 25044085 · NCT01270841)
8. Constantinou BT, et al. (2026). Clomiphene citrate versus testosterone replacement therapy in male hypogonadism: a systematic review of literature and meta-analysis. European Journal of Clinical Pharmacology, 82(8).(PMID 42435198)
9. Bandura A, et al. (2026). Clomiphene Citrate in off-Label Post-Cycle Therapy: Mechanisms, Efficacy and Diagnostic Challenges in Endocrine Recovery Following Anabolic Steroid Use. Andrology (2026).(PMID 42387872)
10. Kim DJ, et al. (2026). Predictors of clomiphene citrate response in the treatment of men with testosterone deficiency. The Journal of Sexual Medicine, 23(7).(PMID 42251758)
11. Foster J, et al. (2026). British Society of Sexual Medicine: Position Statement for the Potential Use of Enclomiphene in the Treatment of Male Hypogonadism. The World Journal of Men's Health, 44(3):480–483.(PMID 41714894)

• HCG (Human Chorionic Gonadotropin) — discussed together in this entry's stacks section
• Testosterone — discussed together in this entry's stacks section
• Tamoxifen — discussed together in this entry's stacks section
• Gonadorelin — shared research area
• Kisspeptin — shared research area
• Melanotan II — shared research area