I had my first hair laser removal on chest and a looks patchy. Will it grow a little more even or stay patchy for ever? (Photo)

Hair has 3 stages of growth [anagen] or active growth phase, a resting phase [ catagen phase],  and [telogen phase] when the hair follicles are extruded and lost.   Laser hair removal only works by targeting the pigment in the follicle of  actively growing hair [ anagen]. Hair that is in the other two phases which is 20- 30% of your is not affected by the laser.  Since not all of your hair is in the same stage of growth at the same time, a series of at least 6-8 treatments a 6 -8 weeks so apart are required for a significant reduction. There no way to know for sure which hair follicle have been treated. What you see by the patchy growth after a couple of treatments is the hair follicles that were not in one of the non growing phase that have cycled into the growing phase. You much complete the 6-8 treatments to be able to asses the adequacy hair removal process.

Having a patchy regrowth is common after the first few treatments. It will become less patchy with more treatments. It takes 6-9 sessions of laser treatment to reduce 70%-90% of the hair. This is because not all hair is in its active growth phase. You may require touch up treatments every 6 months. Please consult with your treating physician if you have any concerns. 

Hair has 3 stages of growth, active, non-active, and a transitional phase.  Laser hair removal works by targeting the pigment in the follicle of te actively growing hair (some of the hair in the transitional phase is also treated).  Hair that is in the non-active phase is not affected by the laser.  Since not all of your hair is in the same stage of growth at the same time, a series of 4-6 treatments a month or so apart are required for best results.  There is no way to predict whether the hair will grow back in a patchy pattern, or just evenly diminished, because there is no way to tell which hair is actively growing at the time of treatment.  Be patient and keep up with your treatments for the best outcome.

Patchy regrowth after laser treatment is common, indicating possibly the areas of patchy regrowth either were not in the active growing stage at the time of treatment, or received less energy than the surrounding areas.This will however normalize and eventually become even. However due to the testosterone, you will require maintenance sessions indefinitely may be a couple of times a year.

Patchy regrowth is common after the early treatments. It will gradually get less patchy with more treatments. You need about 5-6 treatments to see significant results. If you did no more, it would fill in as if you didn't have any treatment.