How Hair-Loss Treatment Works

Most people who notice thinning hair have androgenetic alopecia, better known as male or female pattern hair loss. It runs in families and it is the reason behind the vast majority of receding hairlines, thinning crowns and widening partings. Understanding why it happens makes the treatment options a lot easier to follow, so let us start there.

Why pattern hair loss happens: DHT and sensitive follicles

Your body produces a hormone called dihydrotestosterone, or DHT, which is made from testosterone. In people with a genetic sensitivity to it, DHT gradually shrinks the hair follicles on the scalp. This is called miniaturisation. Each affected follicle produces a thinner, shorter, weaker hair with every growth cycle, until eventually it stops producing a visible hair at all.

This is a slow process that happens over years, not weeks. It also follows a predictable pattern, which is why men tend to lose hair at the temples and crown, and women tend to see a diffuse thinning across the top of the scalp. The follicles at the back and sides of the head are usually less sensitive to DHT, which is why they often keep growing hair even when the top has thinned.

Not all hair loss is driven by DHT. Sudden shedding after illness, high stress, childbirth or a crash diet is usually telogen effluvium, and thyroid problems, low iron, certain medications and tight hairstyles can also cause hair to thin. If your hair loss came on quickly or does not follow the usual pattern, it is worth having the cause checked properly before starting treatment. You can read more on our causes of hair loss page.

How the main treatments work

Because pattern hair loss is driven by DHT and by the follicle's response to it, the evidence-based treatments work in two main ways: they either reduce DHT, or they support the follicles directly. Most people who treat it seriously use one or both.

Finasteride: lowering DHT (men)

Finasteride is a prescription tablet for men. It blocks the enzyme (5-alpha-reductase) that converts testosterone into DHT, which lowers the amount of DHT in the body and scalp. With less DHT reaching the follicles, the miniaturisation process slows down, and in many men the follicles recover enough to produce thicker hair again.

Finasteride is not suitable for women who are pregnant or who may become pregnant, and it is prescribed for men only. Like any prescription medicine it has possible side effects, which an HPCSA-registered doctor will go through with you before you start. You can read a fuller breakdown on our finasteride vs minoxidil comparison.

Minoxidil: supporting the follicle (men and women)

Minoxidil is a topical treatment applied to the scalp, and it is used by both men and women. It works differently to finasteride. Rather than lowering DHT, it improves blood flow to the follicles and prolongs the active growth phase of the hair cycle, which helps follicles produce longer, thicker hairs and keeps more of them growing at once.

Because minoxidil does not touch hormones, it is one of the standard options for women as well as men. For some women, a doctor may also consider spironolactone, a prescription medicine used off-label to reduce the effect of androgens. That is always a decision made with a registered doctor based on your individual situation.

Realistic timelines: what to expect

Hair grows slowly, so treatment takes time to show. As a rough guide:

• First few weeks: some people notice a temporary increase in shedding as older hairs are pushed out and replaced. This can be unsettling but is often a normal early sign that the hair cycle is resetting.
• 3 to 6 months: this is when most people start to see a real difference, usually as reduced shedding first and thicker hair over the crown or parting.
• 6 to 12 months: the fuller picture of what treatment can do for you becomes clear. Judging results before six months usually means judging too early.

These treatments are maintenance-dependent. They control an ongoing genetic process rather than curing it, so the gains hold only while you keep using them. If you stop, DHT goes back to its previous level and, over the following months, the hair you kept or regrew is gradually lost again. It is worth being honest with yourself about this before you start, because consistency matters more than any single product.

What "working" actually looks like

It helps to have the right expectation. For most people, a good result is not a full head of teenage hair. Success usually means one or more of the following:

• The loss slows down or stops, so you are no longer watching your hairline retreat.
• Shedding reduces, so less hair ends up in the shower drain and on the pillow.
• Some genuine regrowth appears, most often over the crown and along a thinning parting, giving better coverage and density.

Slowing or halting further loss is itself a real win, because keeping the hair you have is far easier than trying to recover follicles that have already shut down. The earlier you act, the more you generally have to protect. Anyone promising guaranteed, dramatic regrowth is overselling it.

This page is general information and not a substitute for medical advice. Any treatment should be started after a consultation with a registered doctor who has reviewed your history.

Starting treatment the right way

The sensible path is to have the cause confirmed and a suitable option chosen with a doctor, rather than guessing. Consultations and prescriptions are handled by Online Doctor SA, with HPCSA-registered doctors and SAPC-registered pharmacy partners, so treatment is dispensed properly and legally.

Read the tailored guidance for men or women, or start when you are ready.

Start a hair-loss consultation

For women, begin here instead: hair-loss treatment for women.