It is the most widespread belief about body hair, and it is false. Shaving makes hair neither thicker, nor darker, nor more plentiful. The illusion is so convincing, though, that almost everyone believes it — here is where it comes from.
Why it is physiologically impossible
A razor cuts the hair at the surface of the skin. What it slices through is dead keratin: the shaft.
Everything that determines a hair’s characteristics — its colour, its diameter, its growth rate — is decided in the follicle, under the skin, by the bulb and the cells around it. The razor never reaches it.
Asking a razor to thicken hair is like expecting a haircut to change your natural colour. The blade acts after the fact, on material already produced and already dead.
Where the illusion comes from
Three phenomena combine, and together they are very convincing.
The cleanly cut tip
A hair that has never been cut ends in a tapered point, often lighter in colour. A shaved hair grows back with a flat cross-section. To the touch, that flat base feels prickly; to the eye, it looks thicker. The hair has not changed diameter: you are seeing its base instead of its tip.
Regrowth all at once
When you shave an area, all the hairs visually restart at the same moment. They emerge together, at the same length, giving an impression of density that natural, staggered regrowth never gives.
Colour near the root
Hair is often more pigmented at its base than at its tip, which is bleached by sun and wear. Shaving brings the darkest part to the surface. The area looks darker although nothing has changed.
What really thickens hair growth
If your hair growth has changed, the cause lies elsewhere — and almost always in hormones.
Under the influence of androgens, fine light down can turn into thick pigmented hair. This is called terminalisation, and it explains most of the changes seen on the face, neck, stomach or chest. Polycystic ovary syndrome, perimenopause or hormonal treatment can trigger it: the subject of our article on laser hair removal and hormones.
Puberty does the same, on its own scale. Many people shave for the first time at exactly the age when hair growth naturally sets in, then credit the razor with what the hormones did. That coincidence founded the myth.
What it changes for laser hair removal
Quite a lot, in fact. This belief pushes people to do the exact opposite of what they should: avoiding the razor in favour of wax or tweezers, “to weaken the hair”.
During a laser protocol, however, shaving is not only allowed, it is required: the day before each session. And wax and tweezers are off limits, because they pull out the root — precisely the laser’s target. We cover this in our article on shaving before a session.
Between sessions, shave as much as you like: it does not slow the treatment, does not make the hair more resistant, and changes nothing about the number of sessions needed.
Two other beliefs, while we are here
“Tweezing makes the hair disappear.” No. It damages the follicle without destroying it, which mainly produces ingrown hairs and hairs that grow back distorted.
“Waxing eventually weakens hair growth.” After very many years, a slight reduction is possible in some people, but it is neither reliable nor predictable. Nothing to do with the targeted destruction of the follicle by a laser.
The only thing that really changes hair
It is reaching the follicle itself. The laser does it by heating it through melanin; electrolysis does it with a current. Everything else — razor, wax, cream, tweezers — acts on the shaft and leaves the root intact.
Curious what your hair would do? The assessment is free, in Uccle, Etterbeek or Watermael-Boitsfort. Book an appointment
