After your first session, your skin may stay smooth for a while, and then a few weeks later you see dark hairs coming back and wonder, “Is it not working?” By the second or third session, another question comes up: “How long do I have to keep doing this?”
Today we have put together what people who have already started laser hair removal ask about most: hair that grows back, how many sessions and how far apart, and what to keep in mind between sessions. What to prepare before your first consultation is covered separately in Brazilian laser hair removal: what should you know if it’s your first time?.
If hair grows back after laser hair removal, does that mean it failed?
In most cases it is not a failure but an expected part of the process. The light from the laser is absorbed by the pigment in the hair and turns into heat, which affects the follicle that makes the hair, and it works best on hair that is actively growing at that moment.
Several reasons overlap when hair becomes visible again.
- Hair that is still shedding Treated hair does not disappear on the spot; it falls out over several days to a few weeks. During this time, it can look as if the hair is growing.
- Hair that was resting at the time Body hair cycles through a growing phase, a phase where it stops and sheds, and a resting phase, each hair at its own pace. Follicles that were resting at the time of treatment are less affected by the laser and send up new hair later.
- Follicles that are weakened but still there Not every follicle that receives heat is affected to the same degree. Some remain with a weakened ability to make hair and may grow hair again that is finer and lighter than before.
However, if hair in or around the treated area seems to have become thicker or more plentiful, be sure to mention it before your next session. Although rare, cases have been reported in which hair around the treated area grows thicker after laser treatment. Also, if thick hair is increasing in several places on your body regardless of treatment, and there are changes in your menstrual cycle or skin as well, it is more important to first check whether there is a hormone-related cause than to simply continue hair removal. In such cases, a laser can reduce the hair that is there now but cannot treat the cause of new hair growth.
So how many laser hair removal sessions do I need?
It is hard to decide in advance that “it will be done in this many sessions.” The range of session numbers given differs between medical institutions and sources, and the number actually needed varies from person to person depending on hair color and thickness, skin color, the area, hormonal status, and the device and settings used.
So rather than focusing on a number, it is more realistic to look at the following together after each session.
| What to check after each session | What to tell us |
|---|---|
| How much hair comes back | Whether it has decreased since last time, stayed about the same, or remains only in certain spots |
| Hair thickness and color | Whether it has become finer and lighter, or whether thick, dark hair remains as before |
| Skin reaction | Whether there was redness, blisters, or color change, and how long it took to settle |
| The result you want | Whether you want almost no hair, or whether it is enough if shaving becomes easier |
The last row matters more than you might think. Even with the same progress, someone who only wants to shave less often and someone who wants hair to be barely visible will stop at different points. Hair with little pigment, such as white hair or very light hair, may not respond much better even with more sessions, so we look at the nature of the remaining hair and decide together whether to continue.
When should I have my next session?
It is decided by how much hair has grown back and how well your skin has recovered, rather than by a date on the calendar. Sources commonly suggest an interval of several weeks, but that interval also varies by area and by person.
Bringing sessions closer together does not make the process finish sooner. If you are treated before resting hair has come up, there is less hair for the laser to act on, and heat may be added again to skin that still has redness or color change from the previous session. If your session ended up later than planned for some reason, please tell us how things have changed in the meantime. We will look at the condition of your skin and hair at that point and set the next plan again.
How should I take care of my skin between sessions?
The basics are to tidy regrown hair by shaving and to keep the treated area away from sunlight and tanning. Because the laser works through the hair root that remains under the skin, what you do in between affects the next session.
- Shave instead of plucking If you pluck with tweezers or wax, the hair the laser needs to follow at the next session is gone. Tidy bothersome hair with a razor, at the skin surface only. If you want to use another method, such as a hair removal cream, it is safer to ask the place where you were treated first.
- Keep the treated area out of the sun Sun-tanned skin is more prone to burns or pigment changes at the next session. If you have plans where the treated area will be exposed, such as a pool or the beach, cover it with clothing and apply sunscreen carefully.
- Take a break from tanning beds and self-tanning products Artificial tanning also changes skin color and affects how the skin reacts to the laser. It is better to pause products that darken the skin during the treatment period.
- Tell us about changes in your health before the next session If anything has changed since last time, such as pregnancy, a new medicine or acne treatment, or recent dermatitis or a herpes flare-up, please tell us before treatment. The timing may need to be postponed or the settings changed.
If I have many sessions, will hair never grow again? What about side effects?
Laser hair removal is a way to reduce how much hair grows, not a method that guarantees every hair will be removed permanently. After completing several sessions, some people see almost no hair for months or even years, but in many cases some hair grows back over time. Hair that grows back is often finer and lighter than before, and occasional additional sessions may be needed to maintain the result.
If you had any of these reactions in a previous session, be sure to tell us before your next treatment. It may be better to proceed after your skin has fully recovered, to adjust the settings and interval, or to give that area a rest.