The principle behind the treatment
Laser hair removal relies on selective photothermolysis — a long phrase for a fairly simple idea. A pulse of light is delivered at a wavelength that is absorbed more strongly by one target than by the surrounding tissue. In hair removal, that target is melanin, the pigment inside the hair.
When the light is absorbed, it converts to heat. That heat travels down the hair shaft to the structures responsible for producing new growth. The aim is to disrupt those structures while leaving the surrounding skin as unaffected as possible.
Why a course is needed
Hair does not grow continuously. Each follicle cycles through an active growth phase, a transitional phase and a resting phase, and at any given moment only a proportion of the hairs in an area are actively growing.
Only hair in that active phase responds well to treatment, because it still has a strong connection to the structures being targeted. This is the entire reason treatment is delivered as a course spaced over weeks rather than in one long appointment.
What affects your results
Because the treatment depends on pigment, hair colour matters. Dark hair contains more melanin and generally responds more predictably than very fine, grey, white or red hair.
Skin also matters. Recent sun exposure, sunbed use or fake tan changes how the skin absorbs light and increases risk, which is why treatment is postponed if the skin is tanned.
- Hair colour and coarseness
- The treatment area — some areas respond faster than others
- Hormonal factors, which may cause new growth over time
- Attending sessions at the recommended intervals
- Avoiding waxing, plucking and threading throughout the course
Realistic expectations
Laser hair removal is usually described as long-term hair reduction rather than permanent removal. Many people find regrowth becomes finer, sparser and slower, and some choose occasional maintenance sessions afterwards.
Anyone promising complete, permanent removal for everyone is overstating what the evidence supports. A consultation and patch test give a far more useful picture of what to expect from your own skin and hair.
About the author
Zazura Team
Aesthetic Practitioner & Co-Founder, Zazura Skin & Laser Clinic
Every treatment begins with a conversation. Your plan follows from understanding your skin, your history and what you would like to change.
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