Is laser hair removal safe?

Does laser hair removal cause cancer?

No. The concern comes from the word "radiation", which is doing a lot of work in the wrong direction.

Ionising radiation — X-rays, gamma rays — carries enough energy to break chemical bonds and damage DNA, which is the mechanism behind radiation-induced cancer. The light used in hair removal is non-ionising. It sits at the opposite end of the spectrum, close to visible light, and it does not carry enough energy per photon to do that.

The light is also absorbed within the skin. It is designed to deposit its energy at the depth of the hair follicle, a couple of millimetres down. It does not reach organs, and there is nothing for it to reach them with.

Does it affect fertility?

No, and the reasoning is the same. Laser used for hair removal penetrates a few millimetres of skin. It does not reach the ovaries, the testes or anything else beyond the dermis.

The question comes up most often about bikini and Brazilian treatments, which is understandable and worth answering directly rather than brushing off: the depth the light reaches is the depth of a hair follicle, and nothing beyond it is affected.

Is it safe during pregnancy?

It is routinely deferred, and that deferral is about the absence of evidence rather than the presence of harm.

No mechanism suggests risk, and no harm has been demonstrated. But laser in pregnancy has not been formally studied, and pregnancy hormones change hair growth so unpredictably that the result is unreliable anyway — hair that clears may return afterwards, and new growth may appear during.

So the sensible answer is to wait. If you are already partway through a course when you become pregnant, tell the clinic; the course pauses and resumes rather than restarting.

The risks that are real

Burns and blistering. Uncommon, and almost always the result of settings too aggressive for the skin type or a device used on recently tanned skin. This is the reason the wavelength question and the patch test question matter.

Post-inflammatory hyperpigmentation — the skin darkening in response to treatment. This is the one that matters on Fitzpatrick IV–V skin, which is most Indian skin. It is usually temporary but can take months to fade, and it is largely a function of settings and sun exposure rather than of laser itself.

Scarring. Rare, and generally a consequence of a burn or of picking at a blister rather than of the treatment.

Paradoxical hypertrichosis — the uncommon effect where treatment at insufficient energy stimulates fine hair at the edge of the treated zone instead of reducing it. Most often seen on the face and neck. It is treatable, and it is an argument for properly assessed settings rather than for a cheaper session.

Our page on side effects covers each of these clinically, including how they are managed.

Does it hurt?

Most people describe a hot flick or a rubber band snap rather than pain, and modern devices chill the skin surface as they fire, which makes a substantial difference.

It varies by area. The upper lip, bikini line and the shin over bone are felt more sharply, because the skin is thin and there is less between the device and the bone. Legs, arms and the back are generally the easiest.

It also gets easier through a course, because there is progressively less hair to absorb the energy. Almost everyone who has waxed the same area finds laser more comfortable, because nothing is being pulled.

Is it safe for teenagers?

It can be, and there are good reasons for it — hirsutism during adolescence can be genuinely distressing, and it is not something to be told to wait out.

Two things change, though. Hormone levels are still shifting, so results are less durable and new growth is more likely; a course completed at fifteen may need revisiting. And where the growth is marked or came on quickly, the cause deserves investigating first: polycystic ovary syndrome and thyroid disorders commonly present this way in teenagers.

Consent from a parent or guardian is required, and the assessment is done with them present.

Long-term effects

Laser hair removal has been in clinical use since the mid-1990s, which is long enough for a delayed systemic effect to have shown up. None has.

The honest limits of what can be said: the treatment is well established, the mechanism is understood, and the complications that occur are local, visible and mostly short-lived. Anyone offering more certainty than that about any medical treatment is overstating it.

Frequently asked