There are a number of risks and complications including:
• Burning/blistering/scarring – as lasers heat up the hair, the skin can often also overheat and occasionally blister, and even potentially scar. This scarring is a relatively rare complication though.
• Partial response – as described above, not all hairs will be treated at any one time with a laser. After a number of treatments, all the hair in the area may have been treated and no hair will grow back again. Fairly commonly, top-up treatments are required, as a few scattered hairs start to grow in the treated area. These top-up treatments are usually just a single treatment every few months, often becoming less needed as time goes on.
• Non response – lasers can only target hairs with dark pigment in them. Blonde, white and silver hairs are therefore very difficult to treat with laser and other methods are probably more suitable for these hair types.
• Change in pigmentation – occasionally, at the same time as the laser reducing the hairs, the colour of the skin itself may also be affected in the treated area. This can result in hypopigmentation (paleness of skin) or hyperpigmentation (darkening of skin). This effect may be temporary, lasting a few months, or can occasionally be lifelong. The risks are higher with darker skin types.
• Pain – the treated area can feel slightly sore or warm after treatment, which usually responds well to simple painkillers. Any pain is usually short-lived and lasts less than a day.
• Infection – blistered and broken skin can allow infection to enter, resulting in a red inflamed area. This may require antibiotics, but could potentially increase the chances of scarring and pigment changes. Cold sores can be activated if the lip area is treated, and some laser specialists will prescribe antibiotics around the time of laser treatment to reduce this risk.
• Increased hair growth – this is a fairly rare occurrence, whereby the hair in the treated area actually starts to grow faster than before. This usually responds to further laser treatment