What Is Finasteride?

Male pattern hair loss (androgenetic alopecia) affects roughly half of men by age 50, and for many it begins in their 20s or 30s. Finasteride (1 mg) is one of the most thoroughly studied prescription treatments designed to halt that progression at the root cause.

Finasteride belongs to a class of medications called type II 5-alpha reductase inhibitors. Rather than acting as a cosmetic thickener, it targets the specific hormone responsible for shrinking genetically sensitive scalp follicles.

How DHT Causes Follicle Miniaturization

Dihydrotestosterone (DHT) is a potent androgen converted from testosterone via the enzyme 5-alpha reductase. In men carrying genetic sensitivity in temples, mid-scalp, and crown follicles, DHT binds to follicular androgen receptors and triggers miniaturization:

• The active growth phase (anagen) progressively shortens with each hair cycle.
• Strands emerge thinner, shorter, and lighter in pigment.
• Left untreated over years, miniaturized follicles eventually become dormant and stop producing visible hair.

How Finasteride Protects and Restores Hair

By selectively blocking the 5-alpha reductase enzyme, a daily 1 mg finasteride tablet reduces scalp and bloodstream DHT levels by more than 60%. Crucially, finasteride does not shut down testosterone production—in fact, circulating testosterone stays within its normal physiological range.

With DHT pressure relieved, vulnerable follicles can recover longer growth cycles:

• Months 1–3: DHT drops rapidly; hair cycles begin resetting beneath the scalp surface.
• Months 3–6: Daily shedding slows noticeably and hairline/crown progression stabilizes in ~80–90% of consistent users.
• Months 6–12+: Miniaturized follicles that remain viable produce thicker, denser terminal hairs.

Consistency matters: if finasteride is discontinued, DHT rebounds to baseline within weeks and protected hair gradually resumes its prior thinning pattern over 6 to 12 months.

Safety, Contraindications, and Potential Side Effects

Because finasteride modulates androgen conversion, a clinical review is required before prescribing:

• Not for women who are or may become pregnant: Women who are pregnant or trying to conceive must not take finasteride or handle crushed/broken tablets due to risks to male fetal development.
• Uncommon sexual side effects: A small percentage of men report reduced libido, milder erections, or decreased ejaculate volume; these typically resolve after stopping treatment or adjusting to a topical formulation.
• Mood monitoring: Rarely, low mood or depressive symptoms have been reported. Anyone with a history of depression should discuss risks carefully with their clinician and stop treatment promptly if mood shifts occur.

Finasteride vs. Minoxidil: Better Together?

Because one shields follicles from DHT while the other stimulates growth, clinicians frequently combine both for stronger, sustained density. Explore discreet, clinician-guided hair care options through Amble.