Laser hair removal uses a focused beam of light absorbed by the pigment (melanin) in hair follicles; the light converts to heat and damages the follicle to reduce future hair growth. It works best over a series of sessions because hair grows in cycles, and only actively growing hairs respond.
How does the laser target hair?
The process relies on selective photothermolysis — the laser emits a single, specific wavelength of light that is preferentially absorbed by melanin in the hair shaft and follicle while sparing surrounding skin. The absorbed energy heats and disables the follicle’s ability to produce new hair. Because a laser is monochromatic and directional, it targets follicles precisely.
Laser hair removal vs. IPL
Laser and IPL both use light, but a laser uses one focused wavelength, while IPL uses a broad spectrum of light. Lasers are generally more precise and efficient for hair reduction and often need fewer sessions than IPL. (IPL is more commonly used as a photofacial for tone, redness, and sun spots.)
Why multiple sessions?
Hair cycles through growth, transition, and resting phases, and lasers only affect hairs in the active growth phase. A typical course is several sessions spaced weeks apart to catch more follicles over time, followed by occasional maintenance.
Who is a good candidate?
Candidacy depends on hair color, skin type, and the treatment area. Modern devices can treat a range of skin tones safely; a consultation confirms the right device and settings for you. Laser targets pigment, so very light, gray, or white hair responds less well.
Safety, results, and downtime
When performed by trained professionals, laser hair removal has a strong safety record. Temporary redness or mild swelling around the follicles is common and usually resolves within hours. Most people return to normal activities the same day. Results build over the series, with lasting reduction in hair density.
Frequently asked questions
Is laser hair removal permanent?
It provides long-lasting hair reduction; occasional maintenance sessions help sustain results.
How many sessions are needed?
Usually a series spaced weeks apart, because only actively growing hairs respond to each session.
Does it hurt?
Most people feel a quick snapping sensation; cooling and device settings improve comfort.
Physician-reviewed educational overview. At MD Laser & Cosmetics in San Mateo, laser hair removal is performed by Dr. Susan Lin, M.D., serving patients within a ~25-mile radius including Burlingame, Foster City, Belmont, San Carlos, Redwood City, Millbrae, Palo Alto and the greater Peninsula. This page is educational and not a substitute for a medical consultation.
References: American Academy of Dermatology · U.S. FDA. For guidance specific to you, consult a physician.