Finasteride / Dutasteride

Evidence: ★★★★★ · Status: FDA Approved

In plain English

Testosterone gets converted into a stronger cousin (DHT) that kills scalp follicles. These drugs block that conversion to save hair — but for a minority, lowering DHT dents libido/mood ("post-finasteride" concerns).

How it works

Inhibit 5α-reductase (SRD5A2), blocking testosterone→DHT conversion. DHT drives male-pattern hair loss and prostate growth. Finasteride hits type II; dutasteride hits I and II.

Molecular target & official sources

SRD5A2 5-alpha reductase 2 (NCBI Gene) · Finasteride (PubChem CID 57363)

Protocol

Finasteride 1 mg/day (hair), 5 mg (prostate).

Watch out

Sexual side effects in a minority, sometimes persistent; not for women of childbearing age.

Bottom line

Most effective hair-loss drug; weigh the sexual-side-effect risk honestly.

Helps with: Hormones & Testosterone · Stress & Anxiety · Sexual Health · Skin & Hair

Stacks with

Shares a pathway — often paired with: Omega-3 (EPA/DHA), Vitamin D3 (+ K2), Testosterone (TRT), Tretinoin / Retinoids.

Availability & where to buy

Available over the counter. Widely available OTC — e.g. iHerb (ships worldwide); in Singapore also Guardian, Watsons, GNC, Shopee / Lazada. Look for a third-party-tested / GMP mark and check the dose per serving.

How it works: the Nuclear receptors pathway →

Used in these protocols

• Hair Loss / Thinning

Compare Finasteride / Dutasteride

• Finasteride / Dutasteride vs Vitamin D3 (+ K2)
• Finasteride / Dutasteride vs Semaglutide (Ozempic / Wegovy / Rybelsus)
• Finasteride / Dutasteride vs Tirzepatide (Mounjaro / Zepbound)
• Finasteride / Dutasteride vs Testosterone (TRT)
• Finasteride / Dutasteride vs Melatonin
• Finasteride / Dutasteride vs Estradiol / Menopausal HRT
• Finasteride / Dutasteride vs Magnesium
• Finasteride / Dutasteride vs Omega-3 (EPA/DHA)