Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
FOLLISTIM vs CHORIONIC GONADOTROPIN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Follistim (follitropin beta) is a recombinant follicle-stimulating hormone (FSH) that binds to FSH receptors on ovarian granulosa cells and testicular Sertoli cells, stimulating follicular development and steroidogenesis.
Chorionic gonadotropin (h CG) binds to the luteinizing hormone/choriogonadotropin receptor (LHCGR) on the surface of gonadal cells, stimulating steroidogenesis and gametogenesis. In females, it triggers ovulation and luteinization; in males, it stimulates Leydig cells to produce testosterone.
Ovulation induction in anovulatory women,Controlled ovarian hyperstimulation for assisted reproductive technologies,Spermatogenesis induction in men with hypogonadotropic hypogonadism
FDA-approved: Induction of ovulation in infertile females (as part of controlled ovarian hyperstimulation),FDA-approved: Treatment of prepubertal cryptorchidism,FDA-approved: Treatment of hypogonadotropic hypogonadism in males,Off-label: Weight loss (not recommended),Off-label: In vitro fertilization protocols
Subcutaneous: 75-300 IU once daily for 7-21 days, adjusted based on response. Intramuscular: 75-150 IU once daily for 7-21 days.
For hypogonadotropic hypogonadism: 1000-2000 IU subcutaneously or intramuscularly 2-3 times per week. For ovulation induction: 5000-10,000 IU intramuscularly as a single dose.
The terminal elimination half-life ranges from 16 to 24 hours (mean ~19 hours) following subcutaneous administration. In patients with renal impairment, half-life may be prolonged, necessitating dose adjustment.
Biphasic: initial half-life ~11 hours, terminal half-life ~23–30 hours. Single-dose half-life ~32 hours; repeated dosing may extend due to accumulation.
Follitropin beta is metabolized primarily in the liver and kidneys via proteolytic degradation; no specific cytochrome P450 involvement.
Primarily metabolized in the liver via proteolytic degradation; undergoes renal excretion with a half-life of 24-36 hours.
Primarily renal; approximately 70% of the dose is excreted unchanged in urine. A minor fraction (less than 5%) appears in feces via biliary elimination. The remainder is metabolized via hepatic pathways to inactive metabolites.
Primarily renal; intact h CG is excreted in urine. Negligible biliary/fecal elimination.
Approximately 45-50% bound, primarily to albumin and to a lesser extent to alpha-2-macroglobulin.
Approximately 80% bound; binds to albumin and sex hormone-binding globulin (SHBG) with low affinity.
Volume of distribution is approximately 0.3 L/kg (range 0.2-0.4 L/kg), consistent with distribution largely into extracellular fluid.
0.3–0.5 L/kg; distributes into extracellular fluid, gonadal tissues, and poorly into fat.
Subcutaneous: Approximately 77% (compared to intravenous administration). Intramuscular: approximately 75%. Not available for other routes.
IM/SC: ~40% to 100% (mean ~78%) due to variable absorption; IV: 100% (not typical). Oral: negligible (<1% due to degradation).
No specific guidelines; use caution in severe impairment (e GFR <30 m L/min/1.73m²) due to limited data.
No specific dose adjustment guidelines available; use with caution in severe renal impairment (GFR <30 m L/min/1.73 m²).
No specific guidelines; use caution in severe hepatic impairment (Child-Pugh C) due to limited data.
No specific dose adjustment guidelines available; use with caution in severe hepatic impairment (Child-Pugh class C).
Not FDA-approved for pediatric use; off-label doses: 75-150 IU subcutaneously daily, weight-based titration (1.5-2.25 IU/kg/day) for adolescent males with hypogonadotropic hypogonadism.
Cryptorchidism: 500-1000 IU subcutaneously or intramuscularly 2-3 times per week for 6 weeks. Delayed puberty: 500-1500 IU subcutaneously or intramuscularly 2-3 times per week.
Not indicated for geriatric use; no dose adjustment recommended, but limited data in elderly >65 years.
No specific dose adjustments; monitor for fluid retention and cardiovascular effects.
Follistim should be used only by physicians experienced in infertility treatment. It may cause ovarian hyperstimulation syndrome (OHSS) and multiple gestations. Serious pulmonary and vascular events have been reported.
None. However, use in females requires careful monitoring to avoid ovarian hyperstimulation syndrome (OHSS), which can be severe.
Ovarian hyperstimulation syndrome (OHSS) can be severe; monitor ovarian response. Risk of multiple gestation and ectopic pregnancy. Ovarian torsion and adnexal torsion reported. Thromboembolic events. Ovarian enlargement may occur. Patients with porphyria may exacerbate condition.
Ovarian hyperstimulation syndrome (OHSS): Risk of severe OHSS with ascites, pleural effusion, and thromboembolic events,Multiple pregnancy: Increased risk due to ovulation induction,Thromboembolic events: Increased risk, especially in patients with prior history,Ovarian enlargement: Monitor with ultrasound,Hormonal-dependent malignancies: Caution in patients with prior history
Hypersensitivity to follitropin beta or any component. High levels of FSH indicating primary ovarian failure. Uncontrolled thyroid or adrenal dysfunction. Ovarian cyst or enlargement unrelated to PCOS. Pregnancy. Sex hormone-dependent tumors (e.g., ovarian, breast, uterine, pituitary). Abnormal genital bleeding of undetermined origin.
Pregnancy,Primary ovarian failure,Uncontrolled thyroid or adrenal dysfunction,Active thromboembolic disorder,Hormone-sensitive tumors (e.g., prostate, breast, ovarian),Hypersensitivity to h CG or any component
No specific food interactions are documented. Grapefruit and grapefruit juice may potentially affect hormone metabolism, though not established for Follistim; advise patients to maintain a consistent diet and report unusual changes.
No known food interactions.
FOLLISTIM (follitropin beta) is classified as Pregnancy Category X. There is no indication for use during pregnancy. Animal studies have shown evidence of fetal abnormalities, and use is contraindicated in pregnant women. In the first trimester, exposure may cause fetal harm; however, no well-controlled studies exist. The drug is not used after conception, as its sole indication is for ovulation induction and controlled ovarian stimulation prior to assisted reproductive technologies.
Chorionic gonadotropin is a pregnancy hormone; exogenous use during first trimester may theoretically alter placental hormone balance, but no increased risk of congenital anomalies has been established. However, use during pregnancy is contraindicated except as part of assisted reproductive technology protocols where its role is physiological. No fetal risks documented from therapeutic use in second or third trimester.
FOLLISTIM is not recommended for use during breastfeeding. It is not known whether follitropin beta is excreted in human milk. Given the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother. No M/P ratio is available.
Chorionic gonadotropin is not orally bioavailable and is likely degraded in infant gastrointestinal tract. Excretion into breast milk is unknown; M/P ratio not established. However, due to its protein nature, transfer is expected to be minimal. Use during breastfeeding is not recommended unless clearly necessary; theoretical risk of hormonal effects on infant.
There are no recommended dosing adjustments for FOLLISTIM during pregnancy because the drug is contraindicated and not used in pregnancy. Pregnancy results from treatment, at which point FOLLISTIM is discontinued. No pharmacokinetic changes are studied in pregnancy as it is not administered to pregnant women.
No pharmacokinetic dose adjustments are recommended in pregnancy as the drug is typically administered only prior to conception or in early pregnancy for luteal phase support. The endogenous hormone levels in pregnancy far exceed exogenous doses. No dose modification required in later trimesters because use is contraindicated.
Follistim (follitropin beta) is a recombinant FSH used for ovulation induction and controlled ovarian stimulation. Monitor estradiol levels and follicular growth via ultrasound to adjust dosing. Risk of ovarian hyperstimulation syndrome (OHSS) increases with high estradiol (>3000 pg/m L) and multiple follicles. Do not use in primary ovarian failure, uncontrolled thyroid/adrenal disorders, or sex hormone-dependent tumors. For subcutaneous administration; rotate injection sites.
Chorionic gonadotropin (h CG) is used to trigger ovulation in assisted reproduction and to treat hypogonadotropic hypogonadism in males. Monitor for ovarian hyperstimulation syndrome (OHSS) in women; discontinue if severe. Do not use in women with primary ovarian failure. In males, may cause gynecomastia or fluid retention.
Follistim is injected subcutaneously exactly as prescribed; do not skip or change dose without talking to your doctor.,You will need regular blood tests and ultrasounds to monitor your response and adjust treatment.,Common side effects include injection site reactions, headache, nausea, and bloating.,Contact your doctor immediately if you experience severe pelvic pain, sudden weight gain, or difficulty breathing, which could indicate ovarian hyperstimulation syndrome (OHSS).,Follistim increases the chance of multiple pregnancy (twins, triplets).,Store vials in the refrigerator, not frozen, and protect from light. Do not use if solution is cloudy or contains particles.
Report abdominal pain, bloating, nausea, vomiting, or rapid weight gain (signs of OHSS).,In males, report breast tenderness or swelling, or fluid retention (swollen ankles/feet).,Do not use if pregnant or breastfeeding unless directed by a specialist.,For fertility: timing of intercourse or IUI is critical; follow cycle monitoring closely.,In males: take as prescribed for testicular descent or hypogonadism; may require multiple doses.
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 FOLLISTIM vs CHORIONIC GONADOTROPIN, answered by our medical review team.
FOLLISTIM is a Gonadotropin that works by Follistim (follitropin beta) is a recombinant follicle-stimulating hormone (FSH) that binds to FSH receptors on ovarian granulosa cells and testicular Sertoli cells, stimulating follicular development and steroidogenesis.. CHORIONIC GONADOTROPIN is a Gonadotropin Hormone that works by Chorionic gonadotropin (h CG) binds to the luteinizing hormone/choriogonadotropin receptor (LHCGR) on the surface of gonadal cells, stimulating steroidogenesis and gametogenesis. In females, it triggers ovulation and luteinization; in males, it stimulates Leydig cells to produce testosterone.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between FOLLISTIM and CHORIONIC GONADOTROPIN 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 FOLLISTIM is: Subcutaneous: 75-300 IU once daily for 7-21 days, adjusted based on response. Intramuscular: 75-150 IU once daily for 7-21 days.. The standard adult dose of CHORIONIC GONADOTROPIN is: For hypogonadotropic hypogonadism: 1000-2000 IU subcutaneously or intramuscularly 2-3 times per week. For ovulation induction: 5000-10,000 IU intramuscularly as a single dose.. 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 FOLLISTIM and CHORIONIC GONADOTROPIN 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. FOLLISTIM is classified as Category C. FOLLISTIM (follitropin beta) is classified as Pregnancy Category X. There is no indication for use during pregnancy. Animal studies have shown evidence of fetal abnormalities, and . CHORIONIC GONADOTROPIN is classified as Category C. Chorionic gonadotropin is a pregnancy hormone; exogenous use during first trimester may theoretically alter placental hormone balance, but no increased risk of congenital anomalies. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.