With the right settings laser hair removal is safe, and the usual after-effect of a session is one thing: redness and slight swelling around the hairs for a few hours. Burns, marks and scars do happen, but almost always for one of three reasons: a tan, too much power or a missed contraindication. No long-term harm to health has been found in decades of use: laser light goes only a few millimetres into the skin and does not reach the organs. Step by step: what is normal, what is not, and how to stay out of the second group.
What most people get after a session
The skin goes red, a small bump appears around each hair, the area feels warm and itches slightly. Often this is only visible and not felt at all. It is the follicle reacting to heat, and it means the flash worked. On the body it passes in 2-6 hours, on the face and bikini area it can last up to a day. No treatment is needed: cool water, a light alcohol-free cream such as panthenol, and loose clothing.
For the first few days the hair keeps growing as if nothing happened, then sheds within one to three weeks. That is normal too, not a sign the course did not work. Pustules around the hairs after a session or shaving are a separate topic: folliculitis after laser hair removal and shaving. Why brows and the skin around the eye are never lasered is covered separately: lasers and eyebrows.
Sources: American Academy of Dermatology
What is rare and why
Burns and blisters. They appear when the skin has taken in too much light: a fresh tan, self-tanner, a dark skin type at high power. The skin goes redder than usual, then a blister, a scab, and within a few weeks it heals. A mark rarely remains if the blister is not popped.
Pigment marks. Dark or light patches where the flashes were, more often on dark and tanned skin and after sun in the first two weeks. Dark marks fade over a few months, light ones last longer. This is the most common of the rare complications, and the sun is almost always behind it.
Folliculitis. Small pustules in the underarms or bikini area one to three days after a session, when infection got onto warmed skin: tight clothing, sauna, a scrub in the first days. It usually passes within a few days, two weeks at most; see a dermatologist if it does not clear or spreads. A separate rare case, increased sweating after underarm laser, is covered in sweating and odor after laser.
Cold sores. For people who get them on the lips, flashes above the lip can trigger one. Tell the specialist in advance, and with frequent outbreaks a doctor prescribes prevention before the session.
Increased hair growth. A rare and little-studied effect: after laser on the face or neck, fine fuzz sometimes gets thicker. It is more common with weak settings and at the edge of the treated area. It is treated with the same laser at the right power.
Scars. They appear only after a deep burn that was not treated, or after a popped blister. With a properly run course they do not happen.
Are there effects years later
There is no data that laser hair removal harms health in the long run. Laser light is not ionising like X-rays, it is ordinary light, only strong and with a wavelength chosen for hair pigment: alexandrite, diode and neodymium each have their own. It is absorbed by pigment in the top millimetres of the skin and goes no further, so it does not affect the internal organs, blood, hormones or fertility. The method has been in use since the mid-1990s, and no delayed effects have been described in that time.
The only thing that really stays for a long time is pigment marks after a sunburn on treated skin. They are not dangerous, but unpleasant, and only time treats them.
Sources: J Am Acad Dermatol, 1996 (PubMed), StatPearls (NCBI), 2023
Does laser hair removal cause cancer
There is no evidence that it does. Skin cancer is caused by ultraviolet from the sun and sunbeds and by ionising radiation, and a hair removal laser works in a different range. Cancer Council Australia calls laser hair removal safe for most people and notes that there are no long-term studies of cancer risk. More on this in the article on contraindications for laser hair removal. The same organisation's caveat: caution with a personal or family history of skin cancer or with atypical moles, so we do not work over moles, we go around them, and with a history of skin cancer a dermatologist makes the call.
Sources: Cancer Council Australia
Face and upper lip: why there are more questions
On the face the skin is thinner, the hair closer to the surface, and the reaction more noticeable: redness lasts longer, swelling and small crusts are more common. The area above the lip is also hormonal: hair there grows under the influence of hormones, is the hardest to remove and needs more sessions than the body. The risk of thicker fuzz is higher here too, so above the lip and on the cheeks the specialist works on precise rather than maximum settings. And the eyes: during flashes on the face closed eyelids are no protection, special goggles are needed, the salon provides them, and without them the face is not treated.
Bikini and underarms
The most sensitive areas and the most common places for folliculitis: warmth, moisture, underwear friction. The first 1-2 days after a session without sauna, pool, tight underwear or scrubs, and most problems never come up. The skin here is darker than on the legs, so the power is lower and cooling matters more.
How to bring the risks down to a minimum
No sun or sunbeds for two weeks before and after. Tell the specialist about medication: some antibiotics, retinoids and acne treatments make the skin sensitive to light. Do not hide pregnancy, cold sores or skin conditions in the area. Come with clean skin, no creams or deodorant. The first days after a session: SPF 50 on exposed areas, no hot baths or sweaty sport. And the most important thing: a device with cooling and a specialist who looks at the skin at every visit.
When to see a doctor
If the redness does not settle for more than two days and spreads, if a blister larger than a centimetre appears, if pustules are spreading, or if two weeks after a session the skin around the flashes is noticeably lighter or darker. All of this is treatable, but better early. Tell the salon too: the specialist will adjust the settings for the next visit.
How we handle it
We work on a hybrid laser with contact cooling: the handpiece cools the skin at the moment of the flash, and that is the main protection against burns. The specialist examines the area at every visit and sets the power for your skin on that day, because after summer it is darker than in spring. Over the years we have seen a great many skin reactions and know how and when to respond to them in time. With a tan, irritation or inflammation in the area the visit is postponed, not "done carefully". In 7 years and more than 3500 treatments burns and marks have been isolated cases for us: laser hair removal never goes entirely without them, and we know how to handle them!
Reviewed by: MEDULLA team