Typically there is 5-6 weeks between treatments to allow regrowth of hairs for the next treatment. Lasers only work on the hairs that are in the growing phase (not the resting or transitional phase - and we can't tell by looking at it which phase the hairs are in). They also work best on light skin and dark hair, although darker skin types can have benefit from the diode or Nd:YAG lasers. Most treatments will reduce about 80% of hair after 5-7 treatments. Facial hair is more difficult to remove due to hormonal influences. Ask your Dermatologic Surgeon if laser hair removal is right for you.
Hi Sarah. The answer is not cut and dried, but here is a good rule of thumb. The resting phase for a hair (how long it stops growing for when it falls out) is 1-4 months. So, the shortest period between treatments we would ever go is 4 weeks and the longest is 4 months. Generally we see good results sticking with a 6-8 week duration between treatments. This gets our patients through the process in a year and minimizes the number of treatments at the same time. Good luck.