Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
JALYN vs PROSCAR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Jalyn is a combination of dutasteride, a 5α-reductase inhibitor that inhibits the conversion of testosterone to dihydrotestosterone (DHT), and tamsulosin, an α1-adrenoceptor antagonist that relaxes smooth muscle in the prostate and bladder neck.
Finasteride inhibits 5α-reductase type II, preventing conversion of testosterone to dihydrotestosterone (DHT) in the prostate, reducing prostate volume and improving urinary symptoms.
Treatment of symptomatic benign prostatic hyperplasia (BPH),Reduction in risk of acute urinary retention,Reduction in risk of need for BPH-related surgery
Benign prostatic hyperplasia (BPH) to improve symptoms, reduce risk of acute urinary retention, and reduce need for surgery,Androgenetic alopecia (male pattern hair loss) - off-label for some formulations
1 capsule (0.5 mg dutasteride/0.4 mg tamsulosin) orally once daily, 30 minutes after the same meal each day.
5 mg orally once daily.
Dutasteride: 5 weeks (t½ ∼3-5 weeks) due to high tissue binding and slow elimination; Tamsulosin: 9-13 hours (t½ ∼9-13 h) in healthy subjects, prolonged in elderly (∼14-15 h).
Terminal elimination half-life is 6-8 hours (range 4-12 hours) in young adults; prolonged to 8-10 hours in elderly (≥70 years), but no dose adjustment required. Steady-state reached after 2 weeks dosing.
Dutasteride is extensively metabolized by CYP3A4 and CYP3A5. Tamsulosin is extensively metabolized by CYP3A4 and CYP2D6.
Primarily metabolized by CYP3A4 to t-butyl side-chain hydroxylated metabolites; minor metabolism by other CYP enzymes.
Dutasteride: 40% renal, 60% fecal as metabolites; Tamsulosin: 76% renal (9% unchanged), 24% fecal as metabolites.
Primarily hepatic metabolism (CYP3A4), metabolites excreted renally (39%) and fecally (57%) as unchanged drug and metabolites.
Dutasteride: 99.0-99.5% bound to albumin and alpha-1-acid glycoprotein; Tamsulosin: 94-99% bound to alpha-1-acid glycoprotein.
Approximately 90% bound to plasma proteins (albumin and alpha-1-acid glycoprotein).
Dutasteride: 300-500 L (∼3-4 L/kg); Tamsulosin: 16 L (∼0.2 L/kg). Dutasteride’s large Vd indicates extensive tissue distribution.
Apparent volume of distribution is 1.4 L/kg (range 0.8-2.0 L/kg), indicating extensive tissue distribution (including prostate, seminal vesicles, and skin).
Oral: Dutasteride ∼60% (capsule); Tamsulosin ∼90% (capsule, under fed conditions slightly reduced).
Oral bioavailability is approximately 63-80% (mean 65% from tablet formulation); food does not significantly affect absorption (Cmax decreased by 8%, AUC unchanged).
No dose adjustment required for mild to moderate renal impairment (GFR ≥30 m L/min). Not recommended for severe renal impairment (GFR <30 m L/min) due to lack of data.
No adjustment required for renal impairment; dose adjustment not studied in GFR < 30 m L/min.
Contraindicated in severe hepatic impairment (Child-Pugh class C). No dose adjustment for mild to moderate impairment (Child-Pugh A or B), but use with caution.
No specific guidelines for Child-Pugh A or B; use with caution in severe hepatic impairment.
Not indicated for use in pediatric patients. Safety and efficacy not established.
Not indicated for use in pediatric patients; safety and efficacy not established.
No specific dose adjustment recommended based on age alone. Monitor for orthostatic hypotension, dizziness, and falls risk, especially in elderly patients. Consider underlying renal and hepatic function.
No specific dose adjustment required; normal adult dosing recommended.
None.
Not approved for use in women or children; finasteride is contraindicated in women who are or may become pregnant due to risk of hypospadias in male fetuses.
Use with caution in combination with other alpha-blockers due to risk of hypotension,Postural hypotension may occur, especially at initiation of therapy,Not recommended for use in women, children, or adolescents due to teratogenic risk,Evaluate for prostate cancer before initiating therapy,Dutasteride may increase risk of high-grade prostate cancer in some studies,Hepatic impairment may alter metabolism of dutasteride
Increased risk of high-grade prostate cancer (Gleason score 8-10) reported in clinical trials; monitor for urinary obstruction; evaluate for other urological diseases; potential for decreased serum PSA levels; sexual dysfunction (decreased libido, erectile dysfunction, ejaculation disorder) may persist after discontinuation; mood changes including depression; breast cancer risk not established.
Hypersensitivity to dutasteride, tamsulosin, or any component of the formulation,Use in women of childbearing potential,Use in pediatric patients
Hypersensitivity to finasteride or any component, women who are or may become pregnant, pediatric patients (not indicated).
Avoid grapefruit juice; may increase tamsulosin exposure and adverse effects. Administer with a meal (same meal consistency daily) to reduce tamsulosin-related adverse events. No other food interactions known.
No significant food interactions. Can be taken with or without meals.
JALYN (dutasteride/tamsulosin) is contraindicated in pregnancy. Dutasteride is a 5-alpha-reductase inhibitor that can inhibit dihydrotestosterone formation, potentially causing abnormal development of external genitalia in male fetuses. Tamsulosin is an alpha-1 blocker with limited data but potential risks. First trimester: avoid; second and third trimesters: avoid due to theoretical risk.
Finasteride is contraindicated in pregnancy (Category X). In first trimester, exposure may cause hypospadias in male fetuses due to inhibition of 5α-reductase; second and third trimester risks include ambiguous genitalia in male fetuses. Avoid handling crushed tablets if pregnant.
JALYN is not indicated for use in women. Dutasteride and tamsulosin are excreted in rat milk but no human data. M/P ratio unknown; avoid breastfeeding due to potential adverse effects in infants.
Finasteride is excreted in breast milk in very low amounts (M/P ratio 0.52). Limited data; use caution. Consider alternative therapy, especially in nursing mothers of male infants due to theoretical risk of antiandrogenic effects.
No dose adjustments are applicable because JALYN is contraindicated in pregnancy. Pharmacokinetic changes in pregnancy are irrelevant as the drug should not be used.
Not applicable; use is contraindicated in pregnancy. No pharmacokinetic studies in pregnancy; no dose adjustments recommended for any trimester as use is not indicated.
Jalyn is a fixed-dose combination of dutasteride (5α-reductase inhibitor) and tamsulosin (α1-adrenergic antagonist) for symptomatic benign prostatic hyperplasia (BPH). Onset of symptom relief is faster than either agent alone. Tamsulosin component may cause orthostatic hypotension, especially in elderly patients; counsel to rise slowly. Dutasteride reduces serum prostate-specific antigen (PSA) by approximately 50% after 6 months; PSA levels should be interpreted accordingly. Avoid use in women of childbearing potential; dutasteride is teratogenic and can be absorbed through skin contact with capsules.
Proscar (finasteride 5 mg) is indicated for benign prostatic hyperplasia (BPH); not interchangeable with Propecia (1 mg) for alopecia. Onset of symptom improvement may take 6-12 months. Monitor serum PSA (multiply by 2 for first 2 years). May cause reversible decrease in libido, ejaculatory dysfunction. Avoid in women of childbearing potential due to teratogenicity (risk of hypospadias).
Take Jalyn 30 minutes after the same meal each day to maintain consistent absorption.,Do not crush, chew, or open capsules; swallow whole.,Avoid grapefruit juice, which may increase tamsulosin levels.,Rise slowly from sitting or lying to prevent dizziness from low blood pressure.,Report symptoms like fainting, severe headache, or prolonged painful erection (priapism) immediately.,Do not donate blood during therapy and for 6 months after stopping due to dutasteride transfer risk.,Use reliable contraception if partner is of childbearing potential; dutasteride can cause fetal harm.
Take once daily with or without food.,Do not crush or split tablets.,Symptom improvement may take 6 months or longer.,Possible side effects include decreased libido, erectile dysfunction, or decreased semen volume.,Women who are pregnant or may become pregnant should not handle crushed or broken tablets.,Regular monitoring of PSA levels is required during treatment.,Do not donate blood while taking this medication.,Report any breast lumps or testicular pain to your healthcare provider.
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 JALYN vs PROSCAR, answered by our medical review team.
JALYN is a 5-Alpha Reductase Inhibitor/Alpha-1 Blocker Combination that works by Jalyn is a combination of dutasteride, a 5α-reductase inhibitor that inhibits the conversion of testosterone to dihydrotestosterone (DHT), and tamsulosin, an α1-adrenoceptor antagonist that relaxes smooth muscle in the prostate and bladder neck.. PROSCAR is a 5-Alpha Reductase Inhibitor that works by Finasteride inhibits 5α-reductase type II, preventing conversion of testosterone to dihydrotestosterone (DHT) in the prostate, reducing prostate volume and improving urinary symptoms.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between JALYN and PROSCAR 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 JALYN is: 1 capsule (0.5 mg dutasteride/0.4 mg tamsulosin) orally once daily, 30 minutes after the same meal each day.. The standard adult dose of PROSCAR is: 5 mg orally once daily.. 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 JALYN and PROSCAR 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. JALYN is classified as Category C. JALYN (dutasteride/tamsulosin) is contraindicated in pregnancy. Dutasteride is a 5-alpha-reductase inhibitor that can inhibit dihydrotestosterone formation, potentially causing abn. PROSCAR is classified as Category C. Finasteride is contraindicated in pregnancy (Category X). In first trimester, exposure may cause hypospadias in male fetuses due to inhibition of 5α-reductase; second and third tri. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.