Hi there,
I've had 5 sessions of facial Alexandrite laser and I have no regrowth now on my cheeks, but sparser and finer my chin, neck and top lip. I had laser everywhere else (yes, there too) over years. It is totally permanent (no growth forever) and effective when done right, with the right laser for your skin type.
The cycles are predictable, for the face:
The first 1.5 - 2 weeks from laser, the hairs from beneath the skin should all fall out. You'll be worried they're growing, but be patient. I find you can pluck them all out after 8 days if you let them "grow" for a couple of days prior. If they're not coming out easily without resistance by the end of 2.5 weeks, they weren't treated effectively (and you'll know if you pluck an active hair, because it will grow back after a week).
From week 2 until around week 6 you should have no growth, except for single hairs that may have been missed or weren't in the growing phase when you were in laser. Some laser clinics will allow you to get a "touch up" at week 4 to catch missed patches.
During weeks 6 - 8 the hairs should nearly all grow back, but finer and less dense,. My laser clinic schedules sessions exactly 8 weeks apart for this reason.
Eventually the hairs will become so fine that they turn into vellus hairs, or if you use a high enough fluence on the laser, they stop growing completely. For me, some body areas required 10 - 12 laser sessions before hair was completely gone (diode laser), but 6 - 8 I believe is average.
