Are there a limit to how many Fraxel Restore one can perform with 4 weeks in between?

Personally I prefer to do one aggressive One-and-Done dual wavelength Fraxel Restore Laser treatment than to do multiple less aggressive treatments because the results are so good and last for several years.  The results are better, but never as good with multiple lesser effective treatments.  It is safe to do multiple lesser aggressive treatments, however, you may never reach the optimum improvement. 

To answer your question, yes, Fraxel can improve acne scars, however there are many other devices out there that are better. The best approach to acne scarring is to find a solution or method, and not a device. See the video below as I explain why I do not like Fraxel for acne scars, but like it for other skin related issues. All the best, DR Davin Lim.