Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
GONAL-F vs DANAZOL
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
GONAL-F (follitropin alfa) is a recombinant human follicle-stimulating hormone (FSH) that binds to FSH receptors on ovarian granulosa cells and testicular Sertoli cells, stimulating follicular development and estrogen production in females and spermatogenesis in males.
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.
Induction of ovulation in anovulatory women with polycystic ovary syndrome (PCOS),Controlled ovarian stimulation for assisted reproductive technologies (ART) such as in vitro fertilization (IVF),Induction of spermatogenesis in men with hypogonadotropic hypogonadism
FDA: Treatment of endometriosis, fibrocystic breast disease, hereditary angioedema,Off-label: Idiopathic thrombocytopenic purpura, precocious puberty, gynecomastia
Subcutaneous injection: 75-300 IU once daily for follicular stimulation; individualized based on response.
300-600 mg orally twice daily; maximum 800 mg/day
Terminal elimination half-life is approximately 24 hours (range 16–32 hours) following subcutaneous administration. This supports once-daily dosing.
Terminal elimination half-life is 4-4.5 hours; clinical context: requires multiple daily dosing to maintain therapeutic levels.
Metabolized via hepatic and renal pathways; exact enzymes not fully characterized. Clearance involves proteolytic degradation and renal excretion.
Primarily hepatic: undergoes oxidation and conjugation via CYP3A4, with metabolites excreted in urine and feces.
Primarily renal (hepatic metabolism and biliary excretion are minor routes). Approximately 80% of the dose is excreted in urine, with less than 20% in feces.
Primarily hepatic metabolism; approximately 60% excreted in feces, 30% in urine as metabolites.
Approximately 70–80% bound to plasma proteins, primarily albumin.
Highly protein bound: 97-99%, primarily to albumin.
Approximately 0.3–0.6 L/kg, indicating distribution primarily into extracellular fluid.
Approximately 1.5 L/kg; indicates extensive distribution into tissues, exceeding total body water.
Subcutaneous: approximately 70% (range 60–80%) relative to intravenous administration.
Oral bioavailability is approximately 100% due to extensive absorption, but first-pass metabolism reduces systemic availability to about 70-80%.
No specific dose adjustments provided; use with caution in severe renal impairment (GFR <30 m L/min).
No adjustment required for GFR ≥10 m L/min; avoid use in GFR <10 m L/min due to fluid retention risk
No specific Child-Pugh based modifications; caution in severe hepatic impairment.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated
Not indicated for use in children; no established pediatric dosing.
2-5 mg/kg/dose orally twice daily; maximum 400 mg/day
Not indicated for use in elderly patients; no specific dosing recommendations.
Start at low end of adult dose, titrate cautiously due to increased risk of fluid retention and thromboembolism
GONAL-F should only be used by physicians experienced in fertility treatment. Ovarian hyperstimulation syndrome (OHSS) is a serious, potentially fatal complication. Patients should be monitored for signs of OHSS. GONAL-F may increase the risk of multiple gestation and pregnancy loss.
Danazol may cause thrombotic events, including pulmonary embolism and thrombophlebitis. It is contraindicated in patients with a history of thrombosis.
Ovarian hyperstimulation syndrome (OHSS): can progress to severe form with respiratory distress, oliguria, and thromboembolism,Ovarian torsion,Multiple pregnancy,Ectopic pregnancy,Pulmonary embolism,Ovarian neoplasia (rare),Hypersensitivity reactions including anaphylaxis
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.
Hypersensitivity to follitropin alfa or any excipient,High levels of FSH indicating primary ovarian failure,Uncontrolled thyroid or adrenal dysfunction,Sex hormone-dependent tumors (e.g., ovarian, breast, uterine, pituitary),Pregnancy and lactation,Ovarian cyst or enlargement of unknown origin
Pregnancy, lactation, porphyria, severe hepatic/renal/cardiac disease, undiagnosed abnormal genital bleeding, history of thromboembolic disorders, androgen-dependent tumors.
No specific food interactions. Maintain adequate hydration to reduce OHSS risk.
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.
GONAL-F (follitropin alfa) is not indicated for use during pregnancy and has no direct fetal risk as it is administered for ovulation induction prior to conception. However, if inadvertent administration occurs during pregnancy, there is a potential risk of luteal phase defect and multiple gestation. Human data on fetal effects are limited; animal studies show no evidence of teratogenicity at clinically relevant doses. No consistent pattern of malformations has been reported.
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.
It is not known whether follitropin alfa is excreted in human breast milk. Due to its protein nature and high molecular weight (approximately 30 k Da), transfer into milk is likely limited. However, because GONAL-F is typically used in fertility treatments and not during breastfeeding, no specific M/P ratio is available. Caution is advised if use is considered during lactation.
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.
GONAL-F is contraindicated during pregnancy; therefore, no dosing adjustments during pregnancy are applicable. Treatment 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.
GONAL-F (follitropin alfa) is a recombinant FSH used for ovulation induction and controlled ovarian stimulation. Monitor estradiol levels and follicle growth via ultrasound to adjust dosing and reduce OHSS risk. Use the lowest effective dose. Do not administer if ovarian cyst or enlargement is present. LH supplementation may be needed in hypogonadotropic hypogonadism.
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.
Inject subcutaneously as directed; rotate injection sites to avoid lipodystrophy.,Report severe pelvic pain, nausea, weight gain, or shortness of breath immediately (OHSS symptoms).,Missed doses can affect cycle; do not double dose without consulting healthcare provider.,Store vials in refrigerator (2-8°C) before mixing; after mixing, use immediately or store refrigerated for up to 28 days.,Avoid pregnancy tests until instructed; false positives may occur from h CG trigger.
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 GONAL-F vs DANAZOL, answered by our medical review team.
GONAL-F is a Gonadotropin that works by GONAL-F (follitropin alfa) is a recombinant human follicle-stimulating hormone (FSH) that binds to FSH receptors on ovarian granulosa cells and testicular Sertoli cells, stimulating follicular development and estrogen production in females and spermatogenesis in males.. 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 GONAL-F 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 GONAL-F is: Subcutaneous injection: 75-300 IU once daily for follicular stimulation; individualized based on response.. 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 GONAL-F 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. GONAL-F is classified as Category C. GONAL-F (follitropin alfa) is not indicated for use during pregnancy and has no direct fetal risk as it is administered for ovulation induction prior to conception. However, if ina. 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.