Everyone in the room wears protective eyewear. Patients describe the pulses as warm pinpricks or a snapped rubber band. A numbing gel, if used, takes 30 to 60 minutes to work. An upper lip takes minutes. The back or legs may take over an hour.[1]
Home / Procedures / Laser Hair Removal / After treatment and risks
After treatment and risks
Laser hair removal reduces hair; it does not remove all of it. FDA clearances define permanent hair reduction as a stable drop in regrowing hairs at 6, 9 and 12 months after a course. Reviews report 30% to 50% clearance
After treatment
Everyone in the room wears protective eyewear. Patients describe the pulses as warm pinpricks or a snapped rubber band. A numbing gel, if used, takes 30 to 60 minutes to work. An upper lip takes minutes. The back or legs may take over an hour.[1]
Redness, swelling and discomfort are common and last 1 to 3 days. The skin can look like a mild sunburn. Most people go back to daily activities the same day.[1][2]
Protect the skin from sun and avoid tanning beds. Wait for a tan to fade before the next session. Do not pluck, since plucking removes the pigmented target. Sessions are usually 4 to 6 weeks apart.[1][2][3]
The AAD reports about a 10% to 25% hair reduction after the first treatment.[1]
Reviews report 30% to 50% hair clearance 6 months after the last treatment. A Cochrane review found about 50% short-term reduction with alexandrite and diode lasers.[1][2]
Most patients stay hair-free for months or years after the series, and maintenance sessions may be needed. Regrown hair is usually sparser, finer and lighter.[1][2][3]
Risks
Lightening or darkening of the skin. Transient pigment changes followed 29% of diode treatments in a 38-subject study and were more common in skin types IV to VI. The AAD says some color changes are permanent.[1][2][3]
Blistering, crusting and erosions occur, mostly on tanned skin and in skin types III and higher. In 150 patients with skin types IV to VI treated with alexandrite, complications occurred in 2%.[1][2][3]
Treated areas can grow more hair. A 2021 meta-analysis of 9,733 patients put the rate at 3%, almost all on the face and neck, and 0.08% elsewhere. It often improved with continued treatment.[1][2]
Rare. No scarring occurred in a 900-treatment series. The AAD lists scarring with blistering, infection and cold sore outbreaks as rare effects.[1][2]
In 2024 the FDA warned that high-lidocaine products used before laser hair removal can cause irregular heartbeat, seizures and breathing trouble. It advises against products over 4% lidocaine, heavy use over large areas and covering the skin with wrap.[1]
Laser hair removal is the most litigated laser procedure. Of 69 laser injury lawsuits from 2012 to 2020, 44 (64%) involved hair removal and 49 (71%) involved a nonphysician operator.[1][2]
The AAD says the patient and everyone in the treatment room wear protective eyewear during laser hair removal.[1]
How long results last
Laser hair removal reduces hair; it does not remove all of it. FDA clearances define permanent hair reduction as a stable drop in regrowing hairs at 6, 9 and 12 months after a course. Reviews report 30% to 50% clearance 6 months after the last session, and a Cochrane review found about 50% short-term reduction with alexandrite and diode lasers. Single studies report 70% to 90% at 12 months with the Nd:YAG in dark skin and lasting loss 2 years after one ruby treatment in 4 of 13 people. Maintenance sessions may be needed.[1][2][3]