Finasteride vs Dutasteride: side-by-side comparison
Finasteride (5-alpha-reductase inhibitor (type II)) and Dutasteride (Dual 5α-reductase inhibitor (type 1 and type 2)) belong to different therapeutic classes and are rarely substitutes for each other. The comparison is useful when a single patient is weighing both options for adjacent or overlapping needs.
| Property | Finasteride | Dutasteride |
|---|---|---|
| Therapeutic class | 5-alpha-reductase inhibitor (type II) | Dual 5α-reductase inhibitor (type 1 and type 2) |
| CAS | 98319-26-7 | 164656-23-9 |
| ATC | G04CB01 | G04CB02 |
| Molecular weight | 372.5 g/mol | 528.53 g/mol |
| Brands with this active ingredient | 1 | 1 |
What they share
Finasteride and Dutasteride share the common regulatory framework for prescription active ingredients, bioequivalence standards for generics, and pharmacist oversight. Beyond that, points in common are limited.
Key differences
Finasteride acts by a different mechanism than Dutasteride, with indications that barely overlap. Comparing the two is useful when a clinician has mentioned both in the same context or the patient wants to understand why one was prescribed instead of the other.
Mechanisms compared
Finasteride: Finasteride binds with high affinity to 5-alpha-reductase type II, blocking the conversion of testosterone into DHT. Dutasteride: Dutasteride irreversibly inhibits both isoenzymes of 5α-reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT).
Indications compared
Finasteride: Finasteride is approved at 5mg per day for the treatment of benign prostatic hyperplasia in adult men, where it reduces prostate volume, improves urinary flow and reduces the risk of acute urinary retention and need for… Dutasteride: Dutasteride is approved for symptomatic benign prostatic hyperplasia, alone or in combination with tamsulosin (Combodart/Jalyn) for greater symptom relief.
Safety profile
Finasteride: Common adverse effects include sexual side effects (decreased libido, erectile dysfunction, ejaculation disorders) reported in approximately 1-3% of men in clinical trials. Dutasteride: Common adverse effects include sexual side effects (decreased libido, erectile dysfunction, ejaculatory disorders), gynaecomastia and breast tenderness.
Frequently asked questions
Is Finasteride better than Dutasteride? ▾
Finasteride and Dutasteride are not "better or worse" — they treat different things. The sensible question is which fits your specific need.
Can Finasteride and Dutasteride be combined? ▾
Whether they can be combined depends on the indications and the interaction profile of each. If both are in a single prescription, the prescriber has weighed it; in self-medication they should never be combined.
Do they have the same side-effect profile? ▾
No — they belong to different classes and have distinct side-effect profiles. Each has its own prescribing information.
Products with Finasteride
Products with Dutasteride
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.