Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
PREGNYL vs ANDRODERM
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.
Testosterone is an androgen receptor agonist; it binds to androgen receptors, leading to changes in gene expression that promote male secondary sexual characteristics and maintain libido, muscle mass, and bone density.
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
FDA-approved: testosterone replacement therapy in males for conditions associated with a deficiency or absence of endogenous testosterone (hypogonadism). Off-label: delayed puberty in males, female-to-male transgender hormone therapy.
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.
Apply one 2.5 mg or 5 mg transdermal system to clean, dry, intact skin on the abdomen, upper arms, or thighs once daily, preferably in the morning. Starting dose is 5 mg daily; adjust based on serum testosterone levels.
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 is approximately 10–100 minutes (rapid), but due to transdermal absorption, effective half-life is extended to about 8–10 hours after patch application.
Primarily renal metabolism and excretion; limited hepatic metabolism.
Testosterone is metabolized primarily in the liver via CYP3A4 and CYP2C9 isoenzymes, as well as by 5α-reductase to dihydrotestosterone (DHT) and by aromatase to estradiol.
Renal: 10-20% as unchanged drug; hepatic metabolism to inactive metabolites; fecal excretion negligible (<5%)
Approximately 90% of testosterone metabolites are excreted in urine as glucuronide and sulfate conjugates; 6% are excreted in feces via bile.
~80% bound primarily to albumin; minor binding to sex hormone-binding globulin (SHBG)
Approximately 98–99% bound: primarily to sex hormone-binding globulin (SHBG, ~40%) and albumin (~60%).
0.5–0.7 L/kg; moderately distributed into extracellular fluid; penetrates gonadal tissues
Volume of distribution is approximately 0.2–0.8 L/kg, reflecting distribution into steroid-sensitive tissues and binding proteins.
Intramuscular: ~100%; Subcutaneous: comparable (~95-100%); Oral: <5% (not used)
Transdermal bioavailability is approximately 10–15% of the nominal dose (based on 24-hour application), with interindividual variability due to skin permeability.
No specific guidelines; use with caution in severe renal impairment (Cr Cl <30 m L/min) due to limited data.
No specific dose adjustment recommended for renal impairment. Use with caution in patients with severe renal impairment due to potential fluid retention.
No specific guidelines for Child-Pugh; use with caution in severe hepatic impairment.
Contraindicated in patients with severe hepatic impairment (Child-Pugh class C). In mild to moderate impairment (Child-Pugh A or B), use with caution and monitor liver function; no specific dose adjustment guidelines.
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 have not been established in children <18 years.
No specific recommendations; use lowest effective dose due to potential increased sensitivity and comorbidities.
Initiate at 2.5 mg once daily in elderly patients due to increased risk of adverse effects, particularly prostatic hyperplasia and cardiovascular events. Monitor serum testosterone levels and adjust as needed.
No FDA black box warning.
WARNING: Cardiovascular risk - Increased risk of myocardial infarction, stroke, and cardiovascular death has been reported with testosterone replacement therapy. Only use in men with confirmed hypogonadism.
Ovarian hyperstimulation syndrome (OHSS) in women,Arterial thromboembolism,Precocious puberty in males,Fluid retention,Ovarian enlargement or cyst rupture
Elderly patients and those with known cardiovascular risk factors should be monitored for cardiovascular events.,May exacerbate sleep apnea in predisposed individuals.,Can cause erythrocytosis; monitor hematocrit.,May accelerate growth of prostate cancer and benign prostatic hyperplasia; monitor prostate-specific antigen (PSA).,Monitor for signs of virilization in women if used off-label.,Possible hypercalcemia in immobilized patients.
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
Men with carcinoma of the breast or known or suspected carcinoma of the prostate.,Women who are pregnant or may become pregnant (risk of virilization of fetus).,Hypersensitivity to testosterone or any component of the product.,Severe renal or hepatic impairment (risk of fluid retention).
No known clinically significant food interactions. Maintain usual diet unless advised otherwise by physician.
No known food interactions. Take with or without food.
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.
Androderm (testosterone) is contraindicated in pregnancy due to virilization of female fetus. First trimester: high risk of pseudohermaphroditism in female fetuses (labial fusion, clitoromegaly) with androgen exposure during critical period of genital differentiation (weeks 8-12). Second and third trimesters: risk of clitoral enlargement, advanced bone age, and potential long-term behavioral effects. Male fetuses may experience premature sexual development. No adequate studies; USP pregnancy category X.
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.
Testosterone is excreted into human milk; M/P ratio not established. Potential for virilization of female infants and early puberty in male infants. Risk of suppression of maternal lactation (androgen-induced decrease in prolactin). Contraindicated during breastfeeding; alternative therapies recommended.
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.
Androderm is contraindicated in pregnancy; no dose adjustments applicable. If therapy is necessary for maternal hypogonadism, discontinue immediately upon pregnancy recognition. Pharmacokinetic changes in pregnancy (increased clearance, volume of distribution) are irrelevant due to contraindication. Do not dose in pregnancy.
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.
Apply to clean, dry, intact skin on the abdomen, thighs, upper arms, or back. Rotate application sites to minimize skin reactions. Do not apply to genitals or scrotum. Avoid showering or swimming for at least 3-4 hours after application to ensure absorption. Monitor serum testosterone levels 14 days after starting therapy or dose adjustment, drawn in the morning before application. Use with caution in patients with known or suspected prostate cancer or breast cancer. Warn patients about the risk of transfer to women and children through skin contact; cover application site with clothing or wash skin before contact.
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.
Apply the gel to clean, dry, intact skin once daily in the morning.,Rotate application sites to prevent skin irritation.,Avoid direct skin contact with women and children; wash hands thoroughly after application and cover the site with clothing.,Do not apply to the genitals or scrotum.,Do not shower or swim for at least 3-4 hours after application.,Monitor for signs of skin irritation, such as redness or itching.,Report any swelling of the ankles, difficulty breathing, or changes in mood or sleep.,Keep the medication away from children and pets.
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 ANDRODERM, 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.. ANDRODERM is a Androgen that works by Testosterone is an androgen receptor agonist; it binds to androgen receptors, leading to changes in gene expression that promote male secondary sexual characteristics and maintain libido, muscle mass, and bone density.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between PREGNYL and ANDRODERM 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 ANDRODERM is: Apply one 2.5 mg or 5 mg transdermal system to clean, dry, intact skin on the abdomen, upper arms, or thighs once daily, preferably in the morning. Starting dose is 5 mg daily; adjust based on serum testosterone levels.. 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 ANDRODERM 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. ANDRODERM is classified as Category C. Androderm (testosterone) is contraindicated in pregnancy due to virilization of female fetus. First trimester: high risk of pseudohermaphroditism in female fetuses (labial fusion, . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.