Is Laser Hair Removal Permanent? Here are the Facts

There are many spurious claims made by some laser hair removal clinics with regard to the permanence of laser treatment.

The truth is, rather disappointingly, that there is no evidence based upon published scientific research to substantiate the claim that laser treatment can achieve permanent hair removal.

There have been a few, lucky individuals who have reportedly had no regrowth in the years following treatment, and conversely some who have experienced complete regrowth.

It should be borne in mind that these are anecdotal and not, by any means, based on sound clinical research.​

FDA Approved – Permanent Hair Reduction

The FDA (US Food and Drug Administration) has recognised and approved certain laser hair removal devices as providing permanent hair reduction.

Their definition of permanent hair reduction is: “the long term, stable reduction in the number of hairs re-growing after a treatment regime, which may include several sessions.”

Permanent hair reduction does not necessarily imply the elimination of all hairs in the treatment area.

How this varies – depending on area of body

The FDA further states that the number of hairs re-growing must be stable over time greater than the duration of the complete growth cycle of hair follicles.

Given that this varies from four to twelve months depending on body location, “permanent” can therefore vary.

Why is the growth cycle significant?​

Close up of hair growth

Hair grows in 3 stages, namely Anagen (growing stage), Catagen (end of growth stage) and Telogen (resting stage). Hairs across each area of treatment are in varying stages of growth but laser treatment is only effective whilst hair is in the growing stage.

Therefore, although the laser beam can cover large areas in one treatment, only those hair follicles in the growing stage will be effectively treated.

The table below illustrates hair growth by body part:

Body Part



Cycle Duration


3 months

1-2 weeks

10 months


3 months

1-2 weeks

10 months


10 weeks

2-3 weeks

14 months

Upper Lip

6 weeks

2-3 weeks

5 months


3 weeks

2-3 weeks

5 months


3 months

2-3 weeks

8 months


16 weeks

2-3 weeks

10 months


24 weeks

3-6 weeks

11-12 months

You will see from the cycle duration column, that upper lip and armpit hair has a much shorter growth cycle than legs or chin.

So, to qualify as permanent hair reduction under the FDA definition, leg hair reduction needs to be stable for 12 months following treatment, whereas armpit hair reduction only needs to be stable for 5 months following treatment.

How many treatments?

Initially, it is likely that a course of between 3 – 8 treatments will be required (depending on size of area to be treated, density of hair and which body part).

Following this, it is usual to require annual follow-up treatments to maintain hair reduction. Hair reduction can be up to 80%​

Is success guaranteed?​

According to the American Society for Dermatologic Surgery it is impossible to determine in advance who will require how many treatments and how long hair will remain gone.

It is therefore impossible to guarantee success and the cost of treatment over a period of time can add up to a considerable outlay.

Patch Tests​

Patch tests, prior to commencement of a treatment programme, can be a useful tool in gauging the likelihood of success as well as judging any possible adverse side effects.

Carried out on a small, inconspicuous area, several days prior to treatment, they are an essential precursor and should always be included.​

Am I likely to be a good candidate?​

“Ideal” candidates for laser hair removal are those with light skin and dark, coarse hair. That is not to say that these conditions are a guarantee of success, but the chances are good.

The reason for this is that the laser beam targets melanin, a dark pigment found in skin and hair. Given that melanin is less prevalent in light skin, and more prevalent in dark hair, especially around the crucial base of the hair follicle, the science behind this is self-explanatory.

Due to advances in technology, there are now some lasers that have had success with darker skin, but you would need to check carefully whether the clinic you are thinking of using has the correct equipment.

Laser hair removal is currently not effective for blond, white, grey or red hair.


Laser hair removal can achieve permanent hair reduction but success cannot be guaranteed in all cases.

It cannot achieve permanent hair removal – for this you would need to consider electrolysis see article: How does Electrolysis compare with Laser Hair Removal

Having taken all the information into account, it is worth remembering that laser hair removal can achieve good results and can treat large areas quickly and efficiently. In the hands of a properly trained and experience practitioner, laser treatment is also safe.


I'm a computer science graduate, have a passion for self development and created this site as a side project due to the lack of complete, understandable, helpful and truthful information about hair removal available online.