the 'rebound' effect


Hi, I’m posting this message again as a new topic as I haven’t had any response from anyone yet - has anyone on this forum had this experience or something similar?

I’m a qualified electrologist working in Spain, and I haven’t decided yet which laser to invest my money in, but I would like to point out that I have three clients who have come to me for electrolysis after finding that laser treatment has stimulated new terminal hair growth. It seems what has happened is that the laser practitioner has tried to treat a few terminal hairs on one small area, but other follicles in the surrounding area have been stimulated to produce thick black hair where previously it was just fine and blond. Two of my clients have had this happen in facial areas (particularly on the the chin and sides of face) and the third has a strip of growth right down the centre of the abdomen. Needless to say, they are all furious with the results of their laser treatment! I think they were all treated with the Candela Gentlelase, which is the most popular laser on the Spanish market, although I’m sure this could happen with other lasers too. I should also point out that all three have a history of hormonal imbalances and are taking or have taken the appropriate medicines to counter this problem. As these particular body areas are all greatly influenced by hormonal problems in terms of hair growth(chin, abdomen etc), do you think I am right in assuming that the people who are most vulnerable to this problem are those who have hormonal problems in the first place?

I actually mentioned this phenomenon to our local Candela salesman, who admitted he had heard of few cases, but that it was a minor problem and after a while this new growth just ‘disappears’ anyway. I was very skeptical about this, as in all my years of fighting against hair growth I have never seen terminal hairs just disappear of their own accord!!!

Would love to hear about other similar experiences and/or get some opinions on this. Thanks all


Not much data as usual on this possible side effect.

Sorry KtB-- I must have missed your earlier question!

There’s a published report that low-fluence laser is capable of causing single hairs to turn to double hairs:

Hairfacts: Ye, 1999 (pili bigemini)

There is anecdotal evidence that plucking and other forms of epilation may cause trauma that induces hair growth, but this has not been observed in the published literature.

It’s hard to say that laser specifically caused the hair they are seeing, but it can’t be ruled out. Women with hormonal issues and PCOS sometimes have unpredictable changes in hair growth patterns.