Hair loss myths: twelve claims, and what is actually true

Almost every man who walks into a hair clinic arrives with a theory, and most of the theories are hair loss myths picked up from a barber, a forum or an advert. They are worth taking apart for a practical reason rather than a pedantic one: every year spent on a shampoo, a supplement or a cold shower is a year in which pattern loss carries on doing what it does, and the hair you could have protected with a real decision is gone. Here are twelve of the common claims, answered plainly, followed by the short list of things that actually do something.

The claim	What is true
Hats cause baldness	No. Only sustained pulling does, and a hat does not pull
The wrong shampoo makes you bald	No. Shampoo washes the scalp; it does not change follicle sensitivity
Hard water causes hair loss	No good evidence. It affects how hair feels, not whether follicles survive
Cutting or shaving makes hair grow back thicker	No. It changes the tip of the shaft, not the follicle
You inherit it from your mother’s father	Partly. Sensitivity is inherited from both sides
Stress made me bald	A severe stressor causes a temporary shed, not pattern loss
Protein shakes and creatine cause hair loss	Not established. Anabolic steroids are a different matter
Scalp massage regrows hair	No. It feels good and does not reverse miniaturisation
High testosterone means baldness	No. Sensitivity to DHT matters, not how much testosterone you have
Cold showers and cold rinses help	No effect on pattern loss
Laser combs and home devices regrow hair	Weak and inconsistent evidence; not a substitute for a decision
A supplement fixes it	Only if a deficiency is the cause, which is uncommon in patterned loss

The myths about things you put on your head

Hats. The idea is that a hat suffocates follicles. Follicles are fed by blood from underneath, not by air from above, so a hat has nothing to suffocate. The only headwear that causes loss is anything that pulls the same hair tight for years, which is traction alopecia, and that is a hairstyle problem rather than a hat problem.

Shampoo. Shampoo is a detergent that spends two minutes on your scalp. It does not reach the mechanism that drives pattern loss, which is a follicle’s inherited sensitivity to a hormone. A shampoo can help a flaky, inflamed scalp, and an inflamed scalp is worth treating, but nothing in a bottle at that price point changes miniaturisation. If you are losing hair on a particular shampoo, you would be losing it on any other.

Hard water. Mineral-heavy water makes hair feel rougher and harder to manage, which is why people in hard-water areas notice their hair more. There is no reliable evidence that it causes follicles to die. Moving house does not fix a receding hairline.

Cutting and shaving. Shaving removes the tapered end of a hair, so what grows back has a blunt end and feels coarser for a while. That is all it is. The follicle underneath is untouched by a razor, and nobody has ever grown a hairline back by shaving it.

The myths about your own body

Your mother’s father. The most persistent one. Androgenetic sensitivity is polygenic and comes from both sides of the family, so a bald maternal grandfather is supporting evidence and not a verdict, and a full head of hair on that side of the family is not protection. The mechanism, and how pattern loss is told apart from every other cause, is on the causes of hair loss in men.

Testosterone. Men with high testosterone are not the ones who go bald, and men with low testosterone are not protected. What matters is how sensitive your follicles are to dihydrotestosterone, which is a receptor question and not a hormone-level question. This is why bodybuilders with visibly high hormone levels keep their hair and slim men with ordinary levels lose it, and vice versa.

Cold showers. A cold rinse constricts blood vessels briefly and makes the hair cuticle lie flatter, which is why hair looks shinier afterwards. It does nothing to a genetically sensitive follicle. Neither does a hot shower cause loss.

Scalp massage. Pleasant, harmless and occasionally recommended as a way to distribute a topical treatment. On its own, there is no good evidence that mechanical stimulation reverses miniaturisation, and aggressive massage on a fragile scalp is not free of consequences. If massage worked, hairdressers would be the least bald profession in the world.

The myths about things you buy

Protein shakes and creatine. Whey protein does not cause hair loss, and creatine has been the subject of one small study that is regularly over-interpreted online. Anabolic steroids are an entirely different conversation: they can accelerate pattern loss substantially in a susceptible man, and that is worth saying plainly to anyone using them.

Supplements. Biotin, collagen, saw palmetto, marine complexes and whatever is being advertised this month all share a problem: they work only if a deficiency is causing your loss, and deficiency is an uncommon cause of patterned loss in men. Iron, vitamin D and thyroid problems are real causes of diffuse shedding and they are diagnosed with a blood test rather than guessed at with a subscription. Getting those checked is worth doing. Taking a supplement for a deficiency you have not been shown to have is not.

Laser combs and home devices. The evidence for low-power light devices in hair loss is weak, inconsistent and mostly funded by the people selling them. Some users report a modest improvement in the appearance of existing hair. None of it regrows a bald area, and the real cost is the eighteen months spent trying before doing anything that works.

Stress, the one with a grain of truth in it

Stress does cause hair loss, and not the kind people mean. A severe physical or emotional stressor, a high fever, major surgery, rapid weight loss or a bereavement can push a large share of follicles into their resting phase at once. Two to four months later they shed together, and by then the trigger is forgotten. That is telogen effluvium, it is diffuse rather than patterned, and it usually recovers when the cause passes.

What ordinary daily stress does not do is convert a full head of hair into a receding hairline. What it does do is make existing pattern loss obvious sooner, because a shed removes some of the hair that was hiding it. This is why men so often date their baldness to one bad year, and why booking surgery during a shedding episode is a bad idea: the graft number you would be quoted is based on hair that is coming back.

What the evidence actually supports

Three things, and the honest version is that they do different jobs.

Finasteride reduces the hormone that shrinks sensitive follicles, and it slows pattern loss and partly thickens hair that has not yet gone. It is for men, it has side effects that are worth reading about properly, and it is a prescription decision with a doctor where you live.

Minoxidil, applied to the scalp, extends the growth phase and improves the calibre of hair that is still there. It works while you use it. It is used by both men and women, and for women it is usually the first option rather than an afterthought. Female pattern loss has its own work-up, and it is on hair loss in women.

Surgery moves follicles that are not sensitive into areas that have already gone. It does nothing for the hair around them, which is precisely why the medical conversation belongs before the surgical one rather than after. Both drugs, what they do and what they do not, are covered on finasteride and minoxidil.

Notice the division of labour. Medication protects what is left; surgery replaces what has gone. A clinic that only ever recommends the thing it sells is not giving you the whole picture, and that includes a surgical clinic.

FAQ

Do hats really not cause hair loss?

Really not. The follicle is supplied by blood vessels underneath the skin and does not need air, so covering the head is harmless. What does cause loss is traction: tight braids, tight ponytails, hair extensions and any style that pulls the same follicles for years, which can eventually damage them permanently. A cap worn daily does not do that. If your hairline is receding in the pattern of the temples, the cause is androgenetic and the hat is a coincidence.

Can stress cause permanent hair loss?

A severe stressor can trigger a diffuse shed that appears two to four months later and usually recovers once the trigger has passed, so in that sense the loss is temporary. Two caveats. Very prolonged shedding can unmask pattern loss that was already underway and will not come back on its own. And hair that was already miniaturised when the shed happened may not recover, because it was on its way out regardless.

Is there any shampoo or supplement worth using?

A medicated shampoo for a flaky or inflamed scalp is worth using, because scalp inflammation is a real condition with real treatment. A supplement is worth taking if a blood test showed you are short of something, most commonly iron in women. Beyond that, the product that has the best evidence for hair loss is not a shampoo or a capsule; it is a prescription decision with a doctor, and it is worth having that conversation a year earlier than you were planning to.

How do I tell a myth from something worth trying?

Three questions do most of the work. Does the claim explain how it affects the follicle, or only what it does to the hair you can see? Is there evidence from someone who was not selling it? And what does it cost you in time, given that pattern loss is progressing while you test it? A cheap product that wastes eighteen months is not cheap. That is the real price of most of the items on this page.

Clinically reviewed by the treating surgeon. Last reviewed 25 September 2026.