Evidence-based information about how treatments work, who they're for, and what to expect.
Male pattern hair loss, known medically as androgenetic alopecia, affects around 50% of men by age 50, and for many it begins in their twenties or early thirties. It is not caused by stress, poor diet, or washing your hair too often. It is driven by genetics and hormones.
The key hormone involved is called DHT (dihydrotestosterone), a byproduct of testosterone. In men who are genetically predisposed, DHT binds to receptors in hair follicles on the scalp and gradually causes them to miniaturise. They produce thinner, shorter hairs with each cycle until eventually they stop producing visible hair altogether.
This process, known as follicle miniaturisation, is progressive. It typically starts at the temples or crown and spreads over time. The follicles are not dead; for much of the process they are still capable of producing hair if the right conditions are restored. This is why early treatment matters significantly. Once a follicle has been miniaturised for long enough, it may become permanently inactive and no longer respond to treatment.
Why acting early matters: Treatment is most effective when follicles are still active. The earlier you start, the more hair there is to preserve, and the better the long-term outcome.
DHT-blocking medicines work by inhibiting the enzyme (5-alpha reductase) that converts testosterone into DHT. By reducing DHT levels in the scalp, these treatments stop the signal that causes follicle miniaturisation, addressing hair loss at its root cause rather than just managing symptoms.
Finasteride is the most studied and widely used DHT blocker for male pattern hair loss. Taken orally once daily, it has been clinically proven to reduce scalp DHT by approximately 60–70%, which is sufficient to halt progression of hair loss in the majority of men and, in many cases, stimulate meaningful regrowth.
Side effects are uncommon. Clinical studies report sexual side effects — including reduced libido and changes in ejaculation — in approximately 1–2% of men. A small number of men also report mood changes or depression. These effects are typically reversible upon stopping treatment. Your doctor will discuss your personal risk profile before prescribing.
Finasteride is a Prescription Medicine. Active ingredient: Finasteride 1mg. Used for the treatment of male pattern hair loss. This medicine has risks and benefits. Consumer Medicine Information is available at medsafe.govt.nz. Forme Health Limited, [registered NZ address].
While DHT blockers address the cause of hair loss, follicle-activating treatments work differently: they promote hair growth by improving blood flow and oxygen delivery to hair follicles, helping dormant or weakened follicles re-enter an active growth phase.
The primary mechanism is vasodilation: relaxing and widening the blood vessels around the follicle, which increases the supply of nutrients and growth factors the follicle needs to function. This can reactivate follicles that have become dormant due to miniaturisation, particularly in the earlier stages when the follicle is still viable.
Minoxidil is the most extensively researched follicle activator, originally developed as a blood pressure medication before its hair growth effects were discovered. It is available in both topical form (applied directly to the scalp) and oral form. Topical application delivers the active ingredient where it's needed while minimising systemic absorption; oral forms achieve higher tissue concentration and are sometimes preferred for their convenience or enhanced efficacy.
Follicle activators work best when used consistently and in combination with a DHT blocker, as they address different mechanisms of hair loss simultaneously.
DHT blockers and follicle activators address hair loss through entirely different pathways, one stopping the cause and the other stimulating regrowth. Used together, they produce meaningfully stronger outcomes than either treatment alone.
The DHT blocker halts the miniaturisation process, protecting existing follicles from further damage. The follicle activator simultaneously works to reactivate dormant follicles and support the growth of existing ones. This combination creates conditions where hair loss is stopped and regrowth is encouraged at the same time.
Individual results vary. Effectiveness data is based on clinical trial outcomes. Not all patients will respond to treatment and outcomes are not guaranteed.
A straightforward guide to recognising early male pattern hair loss — what to look for, what's normal, and when it's worth acting.
Read article →What to expectWhat to expect in the first weeks, months, and year of treatment — including why things might look worse before they get better.
Read article →ScienceThe standard system for classifying male pattern baldness. Here's what each stage means and how it affects your options.
Read article →ScienceDHT is the hormone responsible for male pattern baldness. Here's how it works and how treatment targets it.
Read article →Getting startedWhat the process looks like from assessment through to receiving your treatment — and what NZ men should know before starting.
Read article →Your doctor will recommend the most appropriate treatment following your assessment. Free, takes 2 minutes.
Start your free assessment →Finasteride is a Prescription Medicine. Finasteride 1mg — for the treatment of male pattern hair loss. This medicine has risks and benefits. For Consumer Medicine Information visit medsafe.govt.nz or speak to your Forme doctor. Forme Health Limited, [registered NZ address].