Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
FERTINEX vs DANAZOL
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Follitropin beta, a recombinant form of human follicle-stimulating hormone (FSH), binds to the FSH receptor on ovarian granulosa cells and testicular Sertoli cells, stimulating follicular development and maturation in women and spermatogenesis in men.
Danazol is a synthetic androgen derived from ethisterone that suppresses pituitary-ovarian axis by inhibiting gonadotropin release, leading to decreased estrogen and progesterone levels. It also has weak androgenic and progestational activity.
Ovulation induction in anovulatory women with polycystic ovary syndrome (PCOS) who have failed to respond to clomiphene citrate,Controlled ovarian hyperstimulation for assisted reproductive technologies (ART) such as in vitro fertilization (IVF),Hypogonadotropic hypogonadism in men
FDA: Treatment of endometriosis, fibrocystic breast disease, hereditary angioedema,Off-label: Idiopathic thrombocytopenic purpura, precocious puberty, gynecomastia
For ovulation induction: 75-150 IU subcutaneously or intramuscularly once daily for 7-12 days; for spermatogenesis: 75-150 IU subcutaneously or intramuscularly 3 times per week.
300-600 mg orally twice daily; maximum 800 mg/day
Terminal elimination half-life is approximately 24-36 hours in patients with normal renal function, supporting once-daily dosing.
Terminal elimination half-life is 4-4.5 hours; clinical context: requires multiple daily dosing to maintain therapeutic levels.
Metabolized primarily via the liver and kidneys; exact enzymes not fully characterized, but involves hepatic degradation and renal excretion.
Primarily hepatic: undergoes oxidation and conjugation via CYP3A4, with metabolites excreted in urine and feces.
Primarily renal excretion of unchanged drug (80-90% of administered dose), with the remainder excreted as metabolites in urine and feces.
Primarily hepatic metabolism; approximately 60% excreted in feces, 30% in urine as metabolites.
Approximately 60-70% bound to plasma proteins, primarily albumin.
Highly protein bound: 97-99%, primarily to albumin.
Vd is approximately 0.3-0.5 L/kg, indicating distribution mainly into extracellular fluid.
Approximately 1.5 L/kg; indicates extensive distribution into tissues, exceeding total body water.
Subcutaneous: ~70% relative to intravenous; intramuscular: ~90% relative to intravenous.
Oral bioavailability is approximately 100% due to extensive absorption, but first-pass metabolism reduces systemic availability to about 70-80%.
No specific dosing guidelines; use with caution in severe renal impairment (Cr Cl <30 m L/min) due to limited data; consider reduced dose or extended interval.
No adjustment required for GFR ≥10 m L/min; avoid use in GFR <10 m L/min due to fluid retention risk
No specific dosing guidelines; use with caution in severe hepatic impairment (Child-Pugh class C) due to limited data; consider reduced dose.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated
For delayed puberty (males): 75-150 IU subcutaneously or intramuscularly 3 times per week; adjust based on testosterone response. For cryptorchidism: 1000-1500 IU subcutaneously or intramuscularly 2-3 times per week for 4-6 weeks; not weight-based but age-adjusted.
2-5 mg/kg/dose orally twice daily; maximum 400 mg/day
Elderly patients are not typically candidates for FERTINEX; no specific dose adjustments recommended due to lack of use; monitor for comorbidities and potential hypersensitivity.
Start at low end of adult dose, titrate cautiously due to increased risk of fluid retention and thromboembolism
FERTINEX should only be used by physicians with expertise in infertility treatment. Ovarian hyperstimulation syndrome (OHSS) may occur, which can be severe and result in ovarian enlargement, pelvic pain, ascites, pleural effusion, and thromboembolic events. Multiple gestation increases the risk of adverse maternal and perinatal outcomes.
Danazol may cause thrombotic events, including pulmonary embolism and thrombophlebitis. It is contraindicated in patients with a history of thrombosis.
Risk of ovarian hyperstimulation syndrome (OHSS), which may be severe and require hospitalization,Increased risk of multiple gestation (twins, triplets, etc.),Ovarian torsion reported,Potential for ovarian enlargement and cyst formation,Thromboembolic events, especially in patients with risk factors,Should not be used in patients with primary ovarian failure, uncontrolled thyroid/adrenal dysfunction, or sex hormone-dependent tumors
Hepatotoxicity (monitor LFTs), pseudotumor cerebri (benign intracranial hypertension), androgenic effects (hirsutism, acne, voice deepening), lipid changes (decreased HDL, increased LDL), thromboembolic events, and premature closure of epiphyses in children.
Pregnancy,Lactation,Primary ovarian failure (elevated FSH levels),Uncontrolled thyroid or adrenal dysfunction,Sex hormone-dependent tumors (e.g., breast, ovarian, uterine),Hypersensitivity to follitropin beta or any component of the formulation
Pregnancy, lactation, porphyria, severe hepatic/renal/cardiac disease, undiagnosed abnormal genital bleeding, history of thromboembolic disorders, androgen-dependent tumors.
No specific food interactions. Maintain a balanced diet rich in folic acid (400-800 mcg/day) to reduce risk of neural tube defects. Avoid excessive alcohol and caffeine.
Take with food or milk to minimize gastrointestinal irritation. Avoid grapefruit juice as it may alter drug metabolism. Limit alcohol consumption due to increased risk of hepatotoxicity.
Fertinex (urofollitropin) is associated with a Category X risk in pregnancy. Administration during pregnancy may cause fetal harm, including congenital malformations (neural tube defects, limb defects) and spontaneous abortion. Use is contraindicated in pregnant women.
Danazol is contraindicated in pregnancy. First trimester exposure is associated with virilization of female fetus including clitoromegaly, labioscrotal fusion, and urogenital sinus abnormalities. Risk in second and third trimesters is also significant due to androgenic effects; fetal growth restriction and preterm birth may occur. No safe gestational period exists.
Safety during breastfeeding has not been established. Excretion in human milk is unknown; no M/P ratio available. Due to potential for serious adverse reactions in nursing infants, breastfeeding is not recommended during treatment.
Danazol is excreted in human milk; M/P ratio not determined. Potential for adverse effects in breastfed infant (e.g., androgenization). Use is contraindicated during breastfeeding due to risk of virilization and other hormonal effects.
No dose adjustments are indicated as Fertinex is contraindicated in pregnancy. Use should be discontinued if pregnancy is confirmed.
Danazol is contraindicated in pregnancy; no dose adjustment recommendations exist. If inadvertently used during pregnancy, discontinue immediately and monitor for fetal effects. Pharmacokinetic changes in pregnancy are not studied; dose modifications are not applicable due to contraindication.
FERTINEX (urofollitropin) is a purified FSH product used for ovulation induction. Monitor ovarian response via serum estradiol levels and transvaginal ultrasound to assess follicle size and number. Adjust dose based on response to minimize OHSS risk. Administer IM or SC after reconstitution. Use caution in patients at risk for thromboembolism.
Monitor liver function tests; androgenic effects (acne, hirsutism, voice deepening) may occur; use with caution in patients with cardiac or renal impairment; may potentiate warfarin; effective for hereditary angioedema prophylaxis; check pregnancy test before initiation due to teratogenicity.
FERTINEX is a hormone injection given under the skin or into a muscle to help you ovulate.,You will need training on how to inject the medication and dispose of needles safely.,Common side effects include headache, bloating, and injection site reactions.,Seek immediate medical attention if you experience severe pelvic pain, sudden weight gain, or shortness of breath.,Avoid alcohol and limit caffeine intake during treatment.,Report any signs of ovarian hyperstimulation syndrome (OHSS) such as nausea, vomiting, or decreased urination.
Do not take if pregnant or planning pregnancy; use effective contraception.,Report symptoms of liver toxicity (jaundice, dark urine, abdominal pain) immediately.,Avoid alcohol as it may increase hepatotoxicity risk.,May cause weight gain, acne, or voice changes; report if bothersome.,Take with food to reduce GI upset.,Use sunscreen due to photosensitivity risk.,Do not discontinue abruptly; taper under medical supervision.
No interactions on record
"Formestane, an aromatase inhibitor, reduces estrogen synthesis, while danazol, a synthetic androgen, possesses weak androgenic and anabolic activity. Concomitant use may lead to additive fluid retention due to danazol's mineralocorticoid-like effects and formestane's potential to cause fluid retention through estrogen withdrawal. This can result in peripheral edema, hypertension, or exacerbation of heart failure in susceptible patients."
"Danazol, a synthetic androgen with weak androgenic activity, may reduce the therapeutic efficacy of vildagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor used for glycemic control in type 2 diabetes. The proposed mechanism involves danazol-induced activation of cytochrome P450 enzymes (particularly CYP3A4) and potential upregulation of glucagon counter-regulatory pathways, leading to increased vildagliptin clearance and diminished inhibition of DPP-4. Clinically, this interaction may result in elevated postprandial glucose levels and reduced HbA1c reduction, compromising glycemic management."
"Danazol, an androgenic steroid, can induce hepatic microsomal enzymes, particularly CYP2C9, which accelerates the metabolism of glipizide, a sulfonylurea antidiabetic agent. This increased clearance reduces glipizide's plasma concentrations, diminishing its insulinotropic effect and potentially leading to hyperglycemia and loss of glycemic control in patients with type 2 diabetes mellitus."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about FERTINEX vs DANAZOL, answered by our medical review team.
FERTINEX is a Gonadotropin that works by Follitropin beta, a recombinant form of human follicle-stimulating hormone (FSH), binds to the FSH receptor on ovarian granulosa cells and testicular Sertoli cells, stimulating follicular development and maturation in women and spermatogenesis in men.. DANAZOL is a Androgen/Antigonadotropin that works by Danazol is a synthetic androgen derived from ethisterone that suppresses pituitary-ovarian axis by inhibiting gonadotropin release, leading to decreased estrogen and progesterone levels. It also has weak androgenic and progestational activity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between FERTINEX and DANAZOL 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 FERTINEX is: For ovulation induction: 75-150 IU subcutaneously or intramuscularly once daily for 7-12 days; for spermatogenesis: 75-150 IU subcutaneously or intramuscularly 3 times per week.. The standard adult dose of DANAZOL is: 300-600 mg orally twice daily; maximum 800 mg/day. 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 FERTINEX and DANAZOL 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. FERTINEX is classified as Category C. Fertinex (urofollitropin) is associated with a Category X risk in pregnancy. Administration during pregnancy may cause fetal harm, including congenital malformations (neural tube d. DANAZOL is classified as Category C. Danazol is contraindicated in pregnancy. First trimester exposure is associated with virilization of female fetus including clitoromegaly, labioscrotal fusion, and urogenital sinus. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.