Is laser hair removal permanent? How long results last
By The Dermatology, Laser & Vein Center
No. Laser hair removal devices are FDA-cleared for permanent hair reduction: a long-term, stable drop in the number of hairs that regrow, measured 6, 9 and 12 months after a full course [1]. That is not the same as clearing every hair. Some finer or lighter regrowth is common, and occasional maintenance sessions are a normal part of keeping the result.
Why does some hair grow back after a full course?
The light is absorbed by the pigment in each hair, and that heat damages the follicle. It only works on follicles in the anagen, or growth, phase, and at any moment many follicles are resting instead [2]. Resting follicles, plus follicles that hormones switch on later, can still produce hair after the course ends. That is why sessions are spaced to catch successive growth cycles, and why it is unlikely any course reaches every hair [2].
How long do laser hair removal results last?
After a completed course, many patients go months or years without new growth, and some need maintenance treatments to keep the area clear [2][3]. In the Cochrane review of randomised trials, alexandrite and diode lasers reduced hair by about 50% for up to six months; the trials were too short to show results beyond that [4]. Four variables decide how long your result holds.
| Effect on regrowth | Effect on maintenance | |
|---|---|---|
| Hair color and contrast | Dark hair absorbs the most heat and responds best. Blonde, gray, white and red hair may respond poorly [2]. | Light hairs that survive the course stay light, and maintenance sessions cannot target hair the laser does not register [2]. |
| Hormones (PCOS, pregnancy) | Excess androgens, as in PCOS, keep stimulating growth. In one trial of women with PCOS, results from laser alone had worsened significantly by 6 months [5]. | Results held better when laser was combined with hormonal treatment from a physician [5]. Treatment is usually postponed during pregnancy [2]. |
| Body area | Paradoxical regrowth, a rare thickening of hair near treated skin, occurs mostly on the face and neck [6]. | New growth on the chin, jaw or neck is worth showing your provider at your next visit rather than treating it as a routine touch-up [6]. |
| Sessions completed vs skipped | The laser only reaches follicles in the growth phase, so each skipped session leaves a cycle of follicles untreated [2]. | Most patients need 6 to 8 sessions about 4 to 6 weeks apart; stopping early leaves more hair for later sessions to catch. |
What changes the answer for your hair and skin?
Hair color. Pigment is the target, so blonde, gray, white and red hairs give the light little to absorb and may not respond [2]. This is why we look at your hair color at the consultation before we plan a course.
Skin tone. Laser hair removal may not work as well on darker skin, because the skin's own pigment competes with the hair's [2]. We use an Nd:YAG wavelength for darker skin tones and set the energy to your skin type.
Hormones. Excess androgens, often from PCOS, drive excess hair growth [2]. In a 150-patient trial, women with PCOS who had laser alone lost ground by 6 months, while those who also took combined oral contraceptives kept better results [5]. If you have a hormonal condition, the physician who manages it decides on medication.
How many sessions will you need, and how often do you come back for maintenance?
Most patients need 6 to 8 sessions, spaced about 4 to 6 weeks apart, with the exact number set by hair density, growth cycle, skin tone and area. Treated hairs shed 7 to 21 days after each session, and any regrowth after the full series tends to be lighter and finer. The breakdown by area is in our guide to how many sessions are needed for laser hair removal.
After the course, occasional maintenance sessions may be needed if regrowth appears. Aftercare is the same after every visit: avoid sun, hot showers and abrasive scrubs for 24 to 48 hours.
When should you check in with your provider?
Sudden, new or coarse hair, especially on the chin, jaw or neck, can signal a hormonal change such as PCOS and is worth raising with a physician before more laser sessions [2][5].
Rarely, hair grows thicker or darker in or near a treated area. This is paradoxical hypertrichosis. A 2021 meta-analysis of 9,733 patients put it at about 3%, mostly on the face and neck, and in most studies it improved with continued treatment [6].
The common side effects are discomfort, redness and swelling that last 1 to 3 days. Rarer ones are blistering, infection, scarring and changes in skin color, some of which can be lasting [3]. Tell your provider about any of these before your next session.
Sources
- [1] U.S. Food and Drug Administration. 510(k) premarket notification K191942, a diode laser hair removal system cleared in 2019 for permanent hair reduction. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K191942
- [2] Cleveland Clinic. Laser Hair Removal: How it Works & What to Expect. https://my.clevelandclinic.org/health/treatments/21757-laser-hair-removal
- [3] American Academy of Dermatology. Laser hair removal: FAQs. https://www.aad.org/public/cosmetic/hair-removal/laser-hair-removal-faqs
- [4] Haedersdal M, Gøtzsche PC. Laser and photoepilation for unwanted hair growth. Cochrane Database of Systematic Reviews, 2006, CD004684. https://doi.org/10.1002/14651858.CD004684.pub2
- [5] Dorgham N, Sharobim A, Haggag H, El-Kalioby M, Dorgham D. Adding combined oral contraceptives or metformin to laser treatment in polycystic ovarian syndrome hirsute patients. Journal of Drugs in Dermatology, 2021;20(3):302-306. https://doi.org/10.36849/JDD.2021.5652
- [6] Snast I, Kaftory R, Lapidoth M, Levi A. Paradoxical hypertrichosis associated with laser and light therapy for hair removal: a systematic review and meta-analysis. American Journal of Clinical Dermatology, 2021;22(5):615-624. https://doi.org/10.1007/s40257-021-00611-w
Common questions
Does laser hair removal hurt?
Most patients describe each pulse as a quick snap, like a rubber band against the skin. Cooling built into our laser systems takes the edge off, and small areas such as the upper lip take 10 to 15 minutes.
How effective is laser hair removal?
In randomised trials, alexandrite and diode lasers reduced hair by about 50% for up to six months after treatment. A full course is usually 6 to 8 sessions, and any regrowth after the full series tends to be lighter and finer.
What is laser hair reduction?
It is the accurate name for what the treatment does. The FDA clears devices for permanent hair reduction, defined as a long-term, stable reduction in the number of hairs regrowing at 6, 9 and 12 months after a treatment course. Fewer hairs return, but not zero.
Is laser hair removal aftercare different between sessions?
No, the routine is the same after every session. Avoid sun, hot showers and abrasive scrubs for 24 to 48 hours, skip strenuous workouts and hot baths for the first day, and shave rather than wax or pluck between visits, because the laser needs the root in place.
How long does laser hair removal last on the face?
There is no fixed figure for the face. The face and neck are where rare paradoxical regrowth concentrates, and hair driven by hormones such as PCOS can return after laser alone, so facial results are the most likely to need occasional maintenance.
Laser Hair Removal is performed at The Dermatology, Laser & Vein Center in Cincinnati under the direction of Balvant Arora, MD, MBA, our medical director and a board-certified plastic surgeon. A consultation is the best way to find out what is realistic for your skin.
This is general information, not medical advice. Candidacy and treatment planning are determined by a licensed provider at consultation.