Dutasteride vs Finasteride: what is the difference?

How they differ

Finasteride and dutasteride both block 5-alpha reductase, the enzyme that turns testosterone into the more potent DHT, and both are used for an enlarged prostate. Finasteride blocks one form of the enzyme, type 2, while dutasteride blocks both type 1 and type 2, which lowers DHT further. The chemical difference is six fluorine atoms: dutasteride replaces finasteride's tert-butyl group with a ring carrying two trifluoromethyl groups, C27H30F6N2O2 at 528.5 against C23H36N2O2 at 372.5. Dutasteride also stays in the body for weeks, against hours for finasteride. Finasteride is also sold as Propecia for hair loss, while dutasteride is sold as Avodart.

Side by side

Structural similarity 0.64 of 1, computed as a Morgan fingerprint Tanimoto coefficient. It measures shape, not effect.

Common questions

What is the difference between Dutasteride and Finasteride?

Finasteride and dutasteride both block 5-alpha reductase, the enzyme that turns testosterone into the more potent DHT, and both are used for an enlarged prostate. Finasteride blocks one form of the enzyme, type 2, while dutasteride blocks both type 1 and type 2, which lowers DHT further. The chemical difference is six fluorine atoms: dutasteride replaces finasteride's tert-butyl group with a ring carrying two trifluoromethyl groups, C27H30F6N2O2 at 528.5 against C23H36N2O2 at 372.5.

Is Dutasteride bigger than Finasteride?

Dutasteride is the heavier molecule, 528.5 g/mol against 372.5 g/mol for Finasteride. Dutasteride is C27H30F6N2O2 and Finasteride is C23H36N2O2.