Why is hair still growing after laser hair removal

The laser heats the hair through its pigment and destroys the follicle, but the hair itself does not vanish. It stays in the skin and over the following days and weeks works its way out like a splinter: the skin pushes it out. From the outside it looks like stubble that is "growing", although the hair is already dead and holding on ever more loosely. Such hairs come out easily if you rub the skin with a washcloth and often end up on the towel after a shower.

This usually takes two to three weeks after a session, faster for some, longer for others. The timing depends on the area and on how deep the hair sat. If you see "growth" in the first days after a visit, that is the normal course of treatment, not a sign that the laser failed. On the contrary: hairs coming out mean the follicles got their dose of heat.

Every hair lives by its own cycle: years of growth, a few weeks of transition and a resting period from a few weeks to a year, depending on the area. According to StatPearls, at any moment 10-15 % of body hairs are resting, and some of the rest are only preparing to grow. The laser destroys a follicle only when the hair is in its growth phase and connected to the root: that is how the heat reaches the target. A dormant follicle with no hair is invisible to the laser.

So after the first session not all the hair goes, only the part that was growing. A few weeks later the next ones wake up and you see new hairs where it was clear after shedding. That is not the old hair coming back, but the first appearance of the ones the laser has not reached yet. That is what the next visits are for: the first three about 4-5 weeks apart, then the interval grows, because fewer and fewer are left to wake up. Cleveland Clinic gives the same reason: follicles are in different stages at different times, hence several treatments. How the intervals are set and why they cannot be fixed "by the calendar" is covered in how often to do laser hair removal.

With every session there are fewer new hairs, and they are thinner and lighter. If after the third or fourth session there is noticeably less hair than before the course, everything is going right, even if something grows between visits.

Sources: StatPearls, hair physiology, Cleveland Clinic, laser hair removal

The feeling that there is more hair usually has two sources. First: the stubble coming out after a session feels coarser than the familiar fuzz after shaving, so you notice it more. Second: between sessions you must not pluck or wax, only shave, and hairs that used to be pulled out by the root are now visible in full. Neither is growth.

Genuine new growth has three causes and different signs: new hairs have appeared on the face or neck, are noticeably darker and coarser than before, or grow where there was none before. That is a reason to tell the specialist and consider tests. Hormonal growth and what to do about it is covered in detail in laser hair removal for hirsutism and PCOS.

• Hormones: polycystic ovary syndrome, pregnancy, menopause, thyroid changes. Follicles the laser did not reach get a stimulus and switch on. A destroyed follicle does not recover by itself, but neighbouring dormant ones can wake up. The Endocrine Society hirsutism guideline lists the same causes.
• Medication and stress: some drugs, including hormonal and steroid ones, and prolonged stress also trigger growth.
• Paradoxical hypertrichosis: a reaction where fine fuzz next to the treated area turns darker and thicker after laser, almost always on the face and neck. A 2025 study in Lasers in Medical Science found it in 16 % of women after alexandrite laser on the face, more often with PCOS, irregular cycles, olive or light-brown skin and after 6-10 sessions.

Sources: Lasers Med Sci 2025, paradoxical hypertrichosis (PubMed), Endocrine Society, hirsutism

• The first 1-3 weeks after a session, hairs come out when rubbed, the skin underneath is smooth: treated hairs are shedding. Nothing to do.
• 4-6 weeks after a session, new hairs have appeared, but fewer and thinner than before the course: dormant follicles have woken up. Time for the next visit.
• In the middle of the course there is noticeably more hair, but it looks the same as before the course: in our experience this is how the body responds to the loss. The best moment for the next session, see the section on more hair after 4-5 sessions.
• Hairs are darker and coarser than before the course, have appeared on the face or neck, or grow where there was none before: hormones or paradoxical hypertrichosis are possible. See the specialist and, if needed, an endocrinologist.

This is a common case: in the middle of the course the growth visibly intensifies and the client decides the laser is not working. There is no need to think that way. In our experience the body is built to make up for losses. Hair removal is a loss for it too, and it starts boosting growth to try to compensate: dormant follicles wake up more in unison than usual, and at one moment more hairs are growing than you are used to seeing.

For the course this is actually better. The laser destroys only the follicle in which a hair is growing right now; it cannot see a dormant one. The more hairs are in active growth by the next visit, the more follicles the laser closes in one session and the better the result after the course. So stronger growth mid-course is not a reason to stop, but a reason to come to the next session on time, while the hairs are growing.

It is a different matter if after six to eight sessions there is not noticeably less hair than before the course. Then the cause is sought in the device and settings, visits that were too far apart, light hair or a hormonal background: come for a consultation with your course history, after a change of range or power the course often continues, and with signs of hormonal growth it is worth having your hormones checked by an endocrinologist at the same time.

Between visits you can and should shave with an ordinary razor: it does not interfere with the course and removes the "it's growing" feeling. The body is shaved the day before a visit, the face is not shaved, the specialist trims the hair. Plucking, waxing and sugaring are out for the whole course: they pull the hair out by the root and the laser has nothing to work on at the next visit. There is no need to help shedding with a scrub in the first days or with tweezers: treated hairs come out on their own, and irritated skin only postpones the next session. More on aftercare in skin care after laser hair removal.

At the consultation we warn you straight away that in the first weeks after a session the hair will "grow", and explain that these are treated hairs coming out. At every visit the specialist compares the area with last time and adjusts the power and range when needed: we have a hybrid laser, alexandrite, diode and Nd:YAG, so the settings for dark hair and for finer hair are different. If the growth does not go down or new hairs appear on the face, we say so directly and advise checking your hormones, while the course continues with an adjustment. Between visits you can always message us and send a photo of the area if anything worries you.