Why Men Go Bald: The Science of Hair Loss and What Actually Works

Walk through any barber shop in Lahore or Karachi and you will see the same thing your father and his father saw. The hairline retreats. The crown thins. Eventually a smooth dome with a horseshoe of hair around the sides. Why men go bald is one of the oldest questions in medicine, and for most of history the answers were nonsense. We finally understand the biology, and the honest version is more interesting than the snake oil ever was.

This article explains what is actually happening on your scalp, why the family-history rumours are half wrong, how to tell ordinary male pattern hair loss apart from the kind that needs a doctor, and which treatments have evidence behind them versus which ones are just selling you hope in a bottle. The short version of why men go bald is a hormone called DHT plus genes that make your follicles listen to it. The longer version is below, and it is worth your time.

Why men go bald: what is happening to the scalp

A single hair is not a permanent fixture. Each follicle runs on a cycle. It grows a hair for two to six years (the anagen phase), rests briefly, then sheds it and starts again. At any moment about 90 percent of your scalp hairs are growing and the rest are resting or falling out, which is why losing 50 to 100 hairs a day is completely normal, as the American Academy of Dermatology notes.

In male pattern baldness, that cycle slowly breaks down. The growing phase gets shorter with each round. The follicle shrinks. The thick, dark, pigmented hair it used to make is replaced by a thinner, shorter, paler one, and then by something so fine you can barely see it. Eventually the follicle produces nothing visible at all. Dermatologists call this miniaturization, and it is the central event in the whole story.

So baldness is not your follicles dying overnight. It is them shrinking over many cycles, over years, until the hair they make is too small to count. The follicle is often still alive underneath. That detail matters a lot when we get to treatment.

One more thing worth understanding about the cycle. The reason loss feels sudden, like you went from a full head to a thin crown in a year, is that miniaturization is invisible for a long time. A follicle can drop from making a thick terminal hair to a slightly thinner one without you noticing a thing. The thinning compounds quietly. By the time the scalp shows through under bright light or a phone camera flash, the process has usually been running for years. This is also why people misjudge what “started” it. The stressful job, the new city, the bad year you blame often only coincided with the moment the loss became visible, not the moment it began.

The medical name and how common it is

The clinical term is androgenetic alopecia. “Andro” for the male hormones involved, “genetic” because your DNA decides whether your follicles respond to those hormones. It is by far the commonest cause of hair loss in men.

Roughly half of all men show noticeable balding by age 50, and the proportion climbs with each decade after that. It can start in the late teens or early twenties. Plenty of Pakistani men notice the first temple recession before they finish university, which is normal even if it feels brutally early.

DHT: the hormone doing the damage

Here is the chain of events. Your body makes testosterone. An enzyme in the skin called 5-alpha-reductase converts some of that testosterone into a more potent androgen called dihydrotestosterone, or DHT. In follicles that carry the sensitive version of the androgen receptor, DHT binds and sends a signal that gradually shortens the growth phase and shrinks the follicle.

That is the whole mechanism in one sentence: testosterone becomes DHT, DHT shrinks vulnerable follicles. The Cleveland Clinic describes DHT as the main hormonal driver of pattern hair loss in both men and women.

The hormone is the trigger. The genetics load the gun.

Why high testosterone does not mean more baldness

A myth worth killing: bald men are not more “manly” or flooded with testosterone. Studies have repeatedly found that men with pattern baldness do not have higher circulating testosterone than men with full heads of hair. What differs is sensitivity. Their follicles react strongly to normal hormone levels. A man with average testosterone and very sensitive receptors will lose hair, while a man with high testosterone and unbothered follicles keeps his.

The same logic explains why castration, historically, stopped pattern baldness. Eunuchs castrated before puberty did not go bald, because without testosterone there was no DHT to act on the follicles. Nobody is suggesting that as a treatment. The point is that it confirmed the hormone link long before anyone could name the enzyme. It also explains why a teenager has not lost hair yet even if his genes guarantee it: the androgen levels that drive the process only ramp up after puberty, which is when DHT-sensitive follicles first start feeling the pressure.

Why the pattern is a pattern

If DHT thinned hair evenly, men would just get thinner all over. Instead baldness follows a map. The follicles at the front, the temples and the crown carry the DHT-sensitive receptors. The follicles along the sides and back of the head mostly do not. This is why the horseshoe rim survives even on a very bald man, and it is the single reason hair transplants work at all. Doctors track the progression with the Norwood scale, which runs from stage 1 (no real loss) to stage 7 (only the side and back rim left).

The mother’s-father myth, and what genetics really says

Almost everyone has heard that you inherit baldness from your mother’s side, specifically her father. Look at your maternal grandfather, the saying goes, and you will see your future. It is a tidy story. It is also mostly wrong.

There is a grain of truth in it. The androgen receptor gene, called AR, sits on the X chromosome, which a man inherits from his mother. A particular variant of AR is strongly linked to male pattern baldness. So your mother’s X-linked genes do carry real weight.

But that is one gene out of many. Large genome-wide studies, including work summarised on Harvard Health, have identified well over a hundred genetic regions tied to male pattern baldness, scattered across many chromosomes inherited from both parents. Baldness is polygenic. Your father’s genes count. Your mother’s count. Your maternal grandfather is one data point among dozens, not a crystal ball.

What this means for predicting your own risk

In practice, the honest answer to why men go bald in a particular family is “look at the whole family.” A bald father, bald uncles on both sides and a bald maternal grandfather together tell you more than any single relative. And because so many genes are involved, two brothers with the same parents can age very differently. One keeps his hairline at 45 while the other is well into a Norwood 4. That is not bad luck in the mystical sense. It is just a different roll of a polygenic dice.

Not all hair loss is pattern baldness

Before you blame DHT, rule out the other causes, because some are reversible and a few are signals of something else going on. The way hair falls tells a doctor a lot. Pattern baldness is gradual and follows the Norwood map. The conditions below behave differently.

Telogen effluvium: stress and illness shedding

A sudden, diffuse shed across the whole scalp, often two to three months after a shock to the body, points to telogen effluvium. A high fever, a major surgery, severe weight loss, a serious infection (a dengue or typhoid episode counts), childbirth in women, or a stretch of intense stress can push many follicles into the resting phase at once. They all shed together a few months later. The good news: it is usually temporary, and the hair grows back once the trigger passes. If you want the wider picture, see our pieces on cortisol and chronic stress and why we get sick and how the body heals.

Nutrition and thyroid

Genuine deficiencies can thin hair. Low iron (very common in South Asian diets, especially among menstruating women and vegetarians), low protein, and low vitamin D are the usual suspects. Vitamin D deficiency is close to universal here. Some Pakistani studies put it above 80 percent of the population, which we covered in vitamin D deficiency in Pakistan. Thyroid disease, both underactive and overactive, also disrupts the hair cycle. The fix in these cases is to correct the underlying problem, not to chase a hair product.

Alopecia areata and scarring loss

Alopecia areata is different again. It is an autoimmune condition where the immune system attacks follicles and hair falls out in sharp, round, coin-sized patches, sometimes overnight. It is not related to DHT. Scarring alopecias, where the follicle is destroyed and replaced by scar tissue, cause permanent loss and need a dermatologist quickly, because the window to save the follicle is short.

What actually works, ranked by evidence

This is the part people skip to, so let us be blunt about it. Once you understand why men go bald, the treatment logic falls into place: anything that helps has to either lower DHT, push follicles back into the growth phase, or physically move resistant follicles. Two medicines have strong, repeated trial evidence. A couple of procedures and devices have a place. Most of what is sold for hair loss does nothing.

Treatment	Evidence	What it does	Rough cost in Pakistan
Minoxidil (topical)	Strong	Extends growth phase, thickens hair; must keep using	~PKR 1,000-2,500 / month
Finasteride (oral)	Strong	Lowers DHT, slows loss; prescription, possible side effects	~PKR 800-2,000 / month
Hair transplant	Good (permanent)	Moves resistant follicles to bald areas; surgeon-dependent	~PKR 80,000-300,000+
Low-level laser	Modest	Small benefit for some; an add-on	Device cost varies
PRP injections	Early / promising	Own blood injected; protocols vary	~PKR 10,000-25,000 / session
Oils, shampoos, biotin*	None for pattern loss	No effect unless correcting a real deficiency	Wasted money

Minoxidil (topical)

Minoxidil started life as a blood-pressure drug, and the hair growth was a side effect doctors noticed. Applied to the scalp as a liquid or foam, it extends the growth phase and can thicken miniaturized hairs. The NHS lists it as one of two main treatments for male pattern baldness. It works best on the crown and on early loss. You have to keep using it. Stop, and within a few months the hair you gained sheds back to where it would have been. Expect some early shedding when you begin, which is the cycle resetting, not the drug failing.

Finasteride (oral), with the honest caveats

Finasteride blocks 5-alpha-reductase, so less testosterone converts to DHT. Lower DHT means less pressure on the follicles. In trials it stops progression in most men and regrows some hair in a meaningful share of them, and the NHS lists it alongside minoxidil as the other proven option. It is the more powerful of the two for slowing the disease.

Now the honest part. A minority of men report sexual side effects: lower libido, erection difficulty, reduced ejaculate. In most studies this affects a small single-digit percentage, and for most it resolves after stopping. A smaller group reports symptoms that persist, an area still debated in the literature. This is a real conversation to have with a doctor, not a decision to make off a forum thread. Finasteride is prescription-only for good reason.

The limits of both drugs

Neither minoxidil nor finasteride brings back hair from a scalp that has been smooth for years. The follicle has to still be there. That is why starting early matters more than almost anything else. Both protect what you have better than they resurrect what is gone, and both stop working when you stop using them. There is no cure that ends the underlying genetics.

Hair transplants

A transplant moves DHT-resistant follicles from the side and back of the head to the bald areas, where they keep their resistance and keep growing. Done well, it is the only permanent way to put hair back on a bald scalp. Done badly, it looks like a doll’s head or fails to take. Results depend heavily on the surgeon, the donor supply, and managing expectations. It does not stop the rest of your native hair from thinning, so many men stay on finasteride afterwards to protect the surrounding hair.

Low-level laser and PRP

Low-level laser therapy (red-light caps and combs) has modest evidence for a small benefit in some men. Platelet-rich plasma, where your own blood is processed and injected into the scalp, shows promising early results but the protocols vary and the long-term evidence is thinner than for the two drugs. Treat both as possible add-ons, not replacements.

What is mostly a scam

Here is where money disappears. Most “anti-hair-fall” shampoos, herbal oils, onion juice, biotin gummies for people who are not deficient, and the endless online powders do not reverse androgenetic alopecia. A shampoo sits on your scalp for ninety seconds and rinses off. It cannot change a hormone signal inside the follicle. Biotin only helps the rare person with a genuine biotin deficiency. If a product promises to regrow a bald crown without a prescription drug or surgery, the promise is empty.

Why do so many people swear these products worked? Two reasons, and both are easy to fall for. First, pattern baldness moves slowly, so a person who starts an oil and sees no further loss over a few months credits the oil for something that was always going to be gradual. Second, a lot of these products are used right after a telogen shed, the temporary kind that was going to recover on its own anyway. The hair grows back, the product gets the praise. A good scalp massage with oil can feel pleasant and may slightly reduce breakage of existing hair, but breakage is not the same as the follicle-level miniaturization that causes baldness. Feeling better about your routine is fine. Just do not expect it to move the Norwood needle.

The Pakistan picture

Pakistan has quietly become a hub for hair transplant tourism, with clinics in Lahore, Karachi and Islamabad charging a fraction of UK or Gulf prices and drawing patients from abroad. Cheaper is not automatically worse, and some Pakistani surgeons are genuinely skilled. But the low end of the market is crowded with under-trained operators and aggressive marketing, and a botched transplant is hard and expensive to fix. Vet the surgeon, see real before-and-after cases from their own hands, and be suspicious of prices that look too good.

Type of hair loss	How it looks	Reversible?	Driver
Androgenetic alopecia	Gradual, Norwood pattern (temples, crown)	No, but treatable	DHT + genes
Telogen effluvium	Diffuse shed all over, weeks after a shock	Usually yes	Stress, illness, weight loss
Nutritional / thyroid	Diffuse thinning, other symptoms present	Yes, if corrected	Iron, vitamin D, protein, thyroid
Alopecia areata	Sharp, round, coin-sized patches	Often, varies	Autoimmune
Scarring alopecia	Smooth scarred patches, redness, pain	No, permanent	Follicle destruction

On the everyday side, minoxidil is widely available in Pakistani pharmacies, and finasteride is sold under several brand names, though it should still be taken on a doctor’s advice. Be wary of the parallel market of imported “miracle” serums and unregulated supplements, which is large here and almost entirely unevidenced.

A note on what you can control

Since why men go bald comes down to genetics you cannot rewrite, the realistic goal is to slow the process and protect what you have. You can avoid making things worse: don’t smoke (it is linked to faster hair loss), manage crash dieting and crash stress that trigger telogen shedding, treat real deficiencies, and protect the donor area if you are ever planning a transplant. Beyond that, the meaningful lever is starting evidence-based treatment early, while there is still hair to save. If you are interested in the wider biology of why hair changes with age, our explainer on why hair turns gray and the one on whether aging can be reversed are good companions to this one.

Frequently asked questions

Does wearing caps or helmets cause baldness?

No. Hats do not cause male pattern baldness. The hair you lose under a cap is just normal daily shedding that you happen to notice when you take it off. Baldness is driven by DHT acting on genetically sensitive follicles, not by anything pressing on your scalp. A cap so tight it cuts off circulation for hours could theoretically irritate hair, but ordinary caps and helmets do nothing.

At what age does male pattern baldness usually start?

It varies widely. Some men see their temples recede in their late teens or early twenties, while others keep a full hairline into their forties. About half of men have noticeable loss by 50. Earlier onset often means more advanced loss later, which is exactly why dermatologists push men who start young to begin treatment sooner rather than waiting.

Can hair loss from stress grow back?

Usually, yes. Stress-related shedding (telogen effluvium) pushes many follicles into the resting phase at once, and they shed a couple of months later. Once the trigger passes, whether it was illness, surgery, severe weight loss or a stressful period, the follicles restart and the hair regrows over several months. This differs from pattern baldness, which is gradual and does not reverse on its own.

Is finasteride safe to take long term?

For most men it is well tolerated over many years. A small percentage report sexual side effects such as lower libido, which usually resolve after stopping. A smaller group reports persistent symptoms, an area still debated. It is prescription-only and the decision should be made with a doctor who can weigh your situation, not based on internet anecdotes alone.

Do biotin or hair supplements work?

Only if you are genuinely deficient, which is uncommon. Biotin helps people with a real biotin deficiency and does nothing measurable for hair loss in everyone else. The same goes for most “hair growth” supplements. If a blood test shows low iron, vitamin D or thyroid problems, correcting those can help. Otherwise the money is better spent on proven treatment.

Will a hair transplant last forever?

The transplanted follicles are taken from the DHT-resistant back and sides, so they keep growing in their new location for life. However, the transplant does not protect your original, non-transplanted hair, which can keep thinning around the grafts. Many men stay on finasteride after surgery to preserve the surrounding native hair and avoid an odd patchy look later.

Should I worry if my hair falls out in patches?

Yes, that warrants a doctor’s visit. Sharp, round, coin-sized bald patches suggest alopecia areata, an autoimmune condition, not ordinary pattern baldness. Sudden patchy loss, redness, scaling, pain or scarring on the scalp all need a dermatologist promptly, because some scarring conditions destroy follicles permanently and the window to save them is short.