Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
PREGNYL vs BRAVELLE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Human chorionic gonadotropin (h CG) acts as a luteinizing hormone (LH) agonist, binding to LH receptors in the gonads, stimulating testosterone production in males and ovulation in females.
Bravelle (urofollitropin) is a purified preparation of follicle-stimulating hormone (FSH) that stimulates ovarian follicular growth and maturation by binding to FSH receptors on granulosa cells, increasing c AMP production and promoting follicular development.
FDA: Treatment of prepubertal cryptorchidism,FDA: Induction of ovulation and pregnancy in anovulatory infertile women,Off-label: Hypogonadotropic hypogonadism in males,Off-label: Assisted reproductive technology (ART) protocols
Ovulation induction in anovulatory women with polycystic ovary syndrome (PCOS),Controlled ovarian hyperstimulation for assisted reproductive technologies (ART) such as in vitro fertilization (IVF)
Intramuscular injection: 5,000-10,000 IU once weekly for 4-9 weeks for ovulation induction; 1,000-2,000 IU three times weekly for spermatogenesis.
For ovulation induction: 150 IU subcutaneously or intramuscularly once daily for 5 days, starting on day 3 or 5 of menstrual cycle. For controlled ovarian hyperstimulation: 150-225 IU subcutaneously or intramuscularly once daily for 5-7 days, then adjust based on response.
Terminal elimination half-life: 23–24 hours; clinically, supports daily or every-other-day dosing; peak effect may lag due to prolonged absorption
Terminal elimination half-life approximately 5-6 hours in healthy adults. Extended in renal impairment (up to 24 hours with Cr Cl <30 m L/min).
Primarily renal metabolism and excretion; limited hepatic metabolism.
Primarily metabolized in the liver via renal excretion; metabolic pathways not fully characterized.
Renal: 10-20% as unchanged drug; hepatic metabolism to inactive metabolites; fecal excretion negligible (<5%)
Primarily renal: 95% of administered dose excreted unchanged in urine within 24 hours. Biliary/fecal: 5% eliminated via feces.
~80% bound primarily to albumin; minor binding to sex hormone-binding globulin (SHBG)
Approximately 10-20% bound to plasma proteins (albumin and α-1 acid glycoprotein).
0.5–0.7 L/kg; moderately distributed into extracellular fluid; penetrates gonadal tissues
Approximately 0.3-0.5 L/kg. Distributing primarily in extracellular fluid; does not extensively penetrate tissues.
Intramuscular: ~100%; Subcutaneous: comparable (~95-100%); Oral: <5% (not used)
Subcutaneous: 90-95% bioavailable relative to intramuscular route. Oral: not clinically used due to enzymatic degradation.
No specific guidelines; use with caution in severe renal impairment (Cr Cl <30 m L/min) due to limited data.
No specific guidelines exist for GFR-based dose modifications; use with caution in severe renal impairment (Cr Cl <30 m L/min) and monitor for adverse effects.
No specific guidelines for Child-Pugh; use with caution in severe hepatic impairment.
No specific guidelines exist for Child-Pugh based modifications; use with caution in severe hepatic impairment and monitor for adverse effects.
Not indicated for prepubertal children; for delayed puberty in males: 1,000-2,000 IU intramuscularly 2-3 times weekly for 3-6 months.
Not indicated for use in pediatric patients; safety and efficacy not established.
No specific recommendations; use lowest effective dose due to potential increased sensitivity and comorbidities.
Not indicated for use in geriatric patients; safety and efficacy not established.
No FDA black box warning.
Bravelle should only be used by physicians who are experienced in infertility treatment and can manage potential serious adverse events, including ovarian hyperstimulation syndrome (OHSS) and multiple gestations.
Ovarian hyperstimulation syndrome (OHSS) in women,Arterial thromboembolism,Precocious puberty in males,Fluid retention,Ovarian enlargement or cyst rupture
Ovarian enlargement and ovarian hyperstimulation syndrome (OHSS) – can lead to serious complications; discontinue treatment if OHSS is suspected.,Multiple gestations – increased risk of multiple births.,Ovarian torsion – report sudden abdominal pain.,Pulmonary and vascular complications – thromboembolic events; discontinue if suspected.,Ectopic pregnancy and spontaneous abortion – higher rates in ART patients.,Neoplasms – risk of ovarian neoplasms with repeated use.
Hypersensitivity to h CG or any component,Premature epiphyseal closure in males,Androgen-dependent neoplasia (e.g., prostate cancer),Undiagnosed uterine bleeding,Ovarian cyst or enlargement due to polycystic ovarian syndrome (PCOS),Active thromboembolic disorders
Hypersensitivity to urofollitropin or any component,High levels of FSH indicating primary ovarian failure,Uncontrolled thyroid or adrenal dysfunction,Known or suspected pregnancy,Ovarian cyst or enlargement of undetermined origin,Abnormal uterine bleeding of undetermined origin,Sex hormone-dependent tumors (e.g., breast, uterus, ovary)
No known clinically significant food interactions. Maintain usual diet unless advised otherwise by physician.
No known food interactions. Maintain normal diet and hydration. Avoid alcohol as it may exacerbate side effects like nausea.
Pregny (h CG) is not indicated for use during pregnancy. h CG is used to induce ovulation and is not continued after conception. In animal studies, high doses have shown fetal abnormalities, but human data are insufficient. First trimester: No direct fetal risk from therapeutic use as it is discontinued before implantation. Second/Third trimester: Not used. Overall, classified as FDA Pregnancy Category X for ovulation induction (contraindicated in pregnancy) but no teratogenic risk if discontinued before conception.
Pregnancy Category X. Urofollitropin is contraindicated in pregnant women due to risk of fetal harm. First trimester: Ovarian hyperstimulation syndrome (OHSS) and multiple gestations. Second and third trimesters: No direct fetal effects reported, but risks associated with multiple gestation (preterm birth, low birth weight). Maternal OHSS may lead to thromboembolism.
Human chorionic gonadotropin (h CG) is normally present in breast milk in low concentrations. Exogenous h CG is likely excreted into breast milk, but the M/P ratio is not established. Due to lack of data and potential for adverse effects in the infant (e.g., hormonal disruption), breastfeeding is not recommended during therapy. The manufacturer advises discontinuing breastfeeding or avoiding the drug.
Urofollitropin is not indicated for use during lactation. No data on excretion in human milk, M/P ratio not established. Use during breastfeeding is contraindicated due to potential for adverse effects on infant hormone levels.
Pregny is contraindicated in pregnancy. No dose adjustment is applicable as it is discontinued prior to conception. There are no pharmacokinetic data for pregnancy, but the drug is not used during gestation.
No dose adjustment applicable as therapy is discontinued upon confirmed pregnancy. No pharmacokinetic data during pregnancy; drug is not used after conception due to contraindication.
Pregnyl (h CG) is used to trigger final follicular maturation and ovulation in assisted reproduction. Monitor for ovarian hyperstimulation syndrome (OHSS); consider withholding h CG if estradiol >4000 pg/m L or >20 follicles per ovary. Administer exactly 36 hours before oocyte retrieval. Intramuscular injection into gluteal muscle; rotate sites if repeated doses.
BRAVELLE (urofollitropin) is a purified FSH product used for controlled ovarian hyperstimulation. Administer subcutaneously; rotate injection sites. Monitor estradiol levels and follicle growth via ultrasound. Risk of ovarian hyperstimulation syndrome (OHSS); consider using Gn RH antagonist protocols to reduce risk. Do not administer if patient has high baseline FSH levels (>15 IU/L) indicating poor ovarian reserve.
Use Pregnyl exactly as prescribed to trigger ovulation; timing is critical for egg retrieval.,Report severe pelvic pain, bloating, nausea, or rapid weight gain (possible OHSS) immediately.,Avoid pregnancy tests during treatment as h CG may cause false positive.,May cause injection site pain or swelling; apply warm compress if needed.,Do not discontinue without consulting your fertility specialist.
Teach proper injection technique and site rotation (abdomen, thigh).,Report immediately if severe pelvic pain, nausea, vomiting, or rapid weight gain occurs (OHSS signs).,Avoid intercourse until instructed to prevent multiple pregnancy.,Inform of multiple pregnancy risk (especially twins).,Store vials in refrigerator (2-8°C) and protect from light.
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 PREGNYL vs BRAVELLE, answered by our medical review team.
PREGNYL is a Gonadotropin Hormone that works by Human chorionic gonadotropin (h CG) acts as a luteinizing hormone (LH) agonist, binding to LH receptors in the gonads, stimulating testosterone production in males and ovulation in females.. BRAVELLE is a Gonadotropin that works by Bravelle (urofollitropin) is a purified preparation of follicle-stimulating hormone (FSH) that stimulates ovarian follicular growth and maturation by binding to FSH receptors on granulosa cells, increasing c AMP production and promoting follicular development.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between PREGNYL and BRAVELLE 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 PREGNYL is: Intramuscular injection: 5,000-10,000 IU once weekly for 4-9 weeks for ovulation induction; 1,000-2,000 IU three times weekly for spermatogenesis.. The standard adult dose of BRAVELLE is: For ovulation induction: 150 IU subcutaneously or intramuscularly once daily for 5 days, starting on day 3 or 5 of menstrual cycle. For controlled ovarian hyperstimulation: 150-225 IU subcutaneously or intramuscularly once daily for 5-7 days, then adjust based on response.. 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 PREGNYL and BRAVELLE 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. PREGNYL is classified as Category C. Pregny (hCG) is not indicated for use during pregnancy. hCG is used to induce ovulation and is not continued after conception. In animal studies, high doses have shown fetal abnorm. BRAVELLE is classified as Category C. Pregnancy Category X. Urofollitropin is contraindicated in pregnant women due to risk of fetal harm. First trimester: Ovarian hyperstimulation syndrome (OHSS) and multiple gestatio. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.