Effects of Finasteride (MK-906), a 5α-Reductase Inhibitor, on Circulating Androgens in Male Volunteers

The conversation discusses whether to use finasteride for hair loss, considering its role in inhibiting DHT and 5AR, which can affect brain function and mood. Some users report anxiety and depression from finasteride, while others do not experience these side effects and emphasize the importance of DHT for brain and prostate health.

Finasteride helps with hair loss by lowering DHT levels in the scalp, which is more important than blood DHT levels. If finasteride is not effective, consulting a doctor or considering switching to dutasteride may be advisable.

FCE 28260 (PNU 156765), an under-explored 5α-reductase inhibitor, showcases promising results in research by Giudici et al., outperforming well-known treatments like Finasteride in reducing the conversion of testosterone to DHT. Its superior efficacy, demonstrated through lower IC50 values in both natural and human recombinant enzyme studies, suggests it could offer more effective management of DHT-related conditions. Additionally, its lower molecular weight hints at better potential for topical application, potentially offering advantages in treating conditions such as androgenic alopecia. Despite its potential, it has not advanced in development, possibly due to financial limitations, leaving its therapeutic prospects and side effect profile largely unexplored.

Dutasteride is recommended for men on testosterone replacement therapy (TRT) with DHT-sensitive hair, as it does not interfere with TRT's anabolic effects and may improve libido and aging male symptoms. Users report varying experiences with libido when switching from finasteride to dutasteride, with some noticing improvements and others experiencing fluctuations.

Dutasteride may inhibit androgen receptors in addition to reducing DHT, potentially explaining its effectiveness over finasteride for hair loss. Concerns about its impact on muscle growth are debated, with some suggesting no significant effects.

Topical androgen receptor antagonists may not be necessary if 5-AR inhibitors like finasteride or dutasteride effectively reduce DHT levels. Combining a 5-AR inhibitor with a topical androgen antagonist could potentially enhance treatment, but oral use of androgen antagonists is too risky due to severe side effects.