Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CLOMIPHENE CITRATE vs EVISTA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Selective estrogen receptor modulator; competes with estrogen for binding at estrogen receptors in the hypothalamus, inhibiting negative feedback and increasing gonadotropin-releasing hormone (Gn RH) secretion, leading to increased LH and FSH release from the pituitary.
Selective estrogen receptor modulator (SERM) that binds to estrogen receptors, acting as an agonist in bone and antagonist in breast and uterine tissues.
Treatment of ovulatory dysfunction in women desiring pregnancy,Off-label: male infertility (oligospermia), induction of ovulation in assisted reproductive technology
Treatment and prevention of osteoporosis in postmenopausal women,Reduction in risk of invasive breast cancer in postmenopausal women with osteoporosis,Reduction in risk of invasive breast cancer in postmenopausal women at high risk for breast cancer
50 mg orally once daily for 5 days, starting on day 5 of menstrual cycle; may increase to 100 mg orally once daily for 5 days if ovulation not achieved.
60 mg orally once daily.
Terminal elimination half-life is approximately 5–7 days (120–168 hours) for the active zu-isomer, with a longer half-life for its metabolites. This prolonged half-life leads to accumulation with repeated dosing and sustained clinical effects.
Terminal elimination half-life is approximately 32.5 hours (range 27-39 hours) for raloxifene and its glucuronide conjugates; clinically relevant for once-daily dosing.
Hepatic metabolism; excreted in feces; active metabolites (possibly enterohepatic recirculation).
Extensively metabolized in the liver via glucuronidation (UGT1A1, UGT1A8, UGT1A9) and CYP3A4-mediated oxidation.
Primarily fecal (approximately 50%), with about 8% renal excretion of unchanged drug and metabolites. Biliary excretion is significant, with enterohepatic recirculation contributing to prolonged elimination.
Raloxifene undergoes extensive glucuronidation; <0.1% excreted unchanged in urine. Approximately 95% is excreted in feces over 5 days (primarily as glucuronide conjugates). Renal elimination of unchanged drug is negligible (<0.1%).
Approximately 80–90% bound to albumin, with significant binding to other plasma proteins including sex hormone-binding globulin (SHBG).
>95% bound to plasma proteins, primarily albumin and α1-acid glycoprotein.
Apparent volume of distribution is large, approximately 50–100 L/kg, indicating extensive tissue distribution and accumulation, particularly in the liver and reproductive organs.
Apparent Vd/F is approximately 1000-1500 L (not weight-based; extensive tissue distribution).
Oral: ~100% absorbed, but bioavailability is difficult to quantify due to extensive first-pass metabolism and enterohepatic cycling; essentially complete systemic exposure after oral administration.
Absolute oral bioavailability is approximately 2% due to extensive first-pass glucuronidation; systemic exposure is dose-proportional.
No specific dose adjustment guidelines; use with caution in severe renal impairment (Cr Cl <30 m L/min) due to limited data.
No dose adjustment required for mild to moderate renal impairment (Cr Cl ≥30 m L/min). Not recommended in severe renal impairment (Cr Cl <30 m L/min) due to lack of data.
Contraindicated in patients with liver disease or hepatic dysfunction; no Child-Pugh based adjustments available.
Contraindicated in patients with Child-Pugh Class B or C hepatic impairment. No specific dose adjustment recommended for Child-Pugh Class A, but use with caution.
Not recommended for use in children; safety and efficacy not established.
Safety and efficacy not established in pediatric patients; no recommended dose.
Not indicated for use in elderly patients; no specific dosing recommendations.
No specific dose adjustment required; use standard adult dosing. Consider increased risk of venous thromboembolism and stroke in elderly women.
Should not be used in patients with liver disease or abnormal uterine bleeding of undetermined origin.
Increased risk of venous thromboembolism (VTE) and death from stroke. Not for use in women with active or history of VTE, including deep vein thrombosis, pulmonary embolism, and retinal vein thrombosis. Not for use in women with atrial fibrillation or other conditions that increase risk of stroke.
Ovarian enlargement/cysts; visual disturbances; multiple pregnancy; ovarian hyperstimulation syndrome; vasomotor symptoms; blurred vision; prolonged use may increase risk of borderline or invasive ovarian tumors.
Risk of VTE; discontinue if VTE occurs. Risk of stroke; discontinue if stroke occurs or for prolonged immobilization. May increase risk of endometrial cancer; monitor for abnormal bleeding. Not for premenopausal women. Use with caution in patients with hepatic impairment or cholestasis. May increase triglycerides; monitor in patients with history of hypertriglyceridemia.
Pregnancy; liver disease or history; abnormal uterine bleeding of undetermined origin; ovarian cyst or enlargement due to polycystic ovary syndrome; hypersensitivity to clomiphene.
Active or history of VTE, pregnancy, women who may become pregnant, lactation, hypersensitivity to raloxifene, or any component of the formulation.
No significant food interactions. Avoid excessive alcohol consumption as it may impair fertility.
Avoid grapefruit and grapefruit juice as they may increase raloxifene levels. No other significant food interactions.
FDA Pregnancy Category X. Clomiphene citrate is contraindicated in pregnancy. First trimester exposure associated with neural tube defects, cleft palate, and syndactyly. Second and third trimester: no data due to contraindication. Risk of multiple gestation (5-12%) increases risks of preterm labor, low birth weight, and congenital anomalies.
Pregnancy Category X. Raloxifene is contraindicated in pregnancy. In animal studies, raloxifene caused fetal abnormalities including skeletal malformations and cardiovascular defects. Human data are unavailable due to contraindication; use in pregnancy may cause fetal harm.
Excreted into breast milk; M/P ratio unknown. Clomiphene may reduce milk production due to anti-estrogenic effects. Because of potential for adverse reactions in nursing infants, women are advised not to breastfeed during treatment.
Raloxifene is excreted in rat milk; no human data available. The M/P ratio is unknown. Due to potential adverse effects on the infant, breastfeeding is not recommended during therapy.
No dose adjustments in pregnancy as drug is contraindicated. If pregnancy occurs, discontinue immediately. No pharmacokinetic studies in pregnant women; drug should not be used.
No dosing adjustments are applicable as raloxifene is contraindicated in pregnancy. Pharmacokinetic changes in pregnancy do not inform dose modifications due to the contraindication.
Monitor ovarian size and estradiol levels to reduce risk of ovarian hyperstimulation syndrome (OHSS). Use only in patients with ovulatory dysfunction; rule out pregnancy before each cycle. Limit to 6 treatment cycles due to increased risk of ovarian cancer with prolonged use.
Monitor for venous thromboembolism; avoid in patients with active or history of VTE. May increase risk of stroke in postmenopausal women with coronary heart disease. No significant effect on breast cancer incidence. Administer with caution in hepatic impairment. Discontinue prior to prolonged immobilization or surgery.
Take clomiphene citrate exactly as prescribed, typically for 5 days starting on day 3-5 of menstrual cycle.,Ovulation usually occurs 5-10 days after the last dose; have intercourse every other day during this window.,Common side effects include hot flashes, mood swings, and visual disturbances; report persistent visual changes immediately.,Risk of multiple pregnancy (mainly twins) is increased; discuss with healthcare provider.,Avoid use if pregnant, have liver disease, or have abnormal vaginal bleeding.
Take once daily with or without food.,Report any signs of blood clots (leg pain/swelling, sudden chest pain, shortness of breath).,May cause hot flashes, leg cramps, or flu-like symptoms.,Avoid pregnancy; not indicated for premenopausal women.,Requires adequate calcium and vitamin D intake.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about CLOMIPHENE CITRATE vs EVISTA, answered by our medical review team.
CLOMIPHENE CITRATE is a Selective Estrogen Receptor Modulator (SERM) that works by Selective estrogen receptor modulator; competes with estrogen for binding at estrogen receptors in the hypothalamus, inhibiting negative feedback and increasing gonadotropin-releasing hormone (Gn RH) secretion, leading to increased LH and FSH release from the pituitary.. EVISTA is a Selective Estrogen Receptor Modulator that works by Selective estrogen receptor modulator (SERM) that binds to estrogen receptors, acting as an agonist in bone and antagonist in breast and uterine tissues.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CLOMIPHENE CITRATE and EVISTA depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of CLOMIPHENE CITRATE is: 50 mg orally once daily for 5 days, starting on day 5 of menstrual cycle; may increase to 100 mg orally once daily for 5 days if ovulation not achieved.. The standard adult dose of EVISTA is: 60 mg orally once daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between CLOMIPHENE CITRATE and EVISTA in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. CLOMIPHENE CITRATE is classified as Category A/B. FDA Pregnancy Category X. Clomiphene citrate is contraindicated in pregnancy. First trimester exposure associated with neural tube defects, cleft palate, and syndactyly. Second and. EVISTA is classified as Category C. Pregnancy Category X. Raloxifene is contraindicated in pregnancy. In animal studies, raloxifene caused fetal abnormalities including skeletal malformations and cardiovascular defec. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.