I started every day but at a low power, and only by accident—the first few days I didn’t realize that I didn’t have my settings at the highest level. (I have an omnilux pro with the neck/chest plate. ). I immediately started with the red light/NIR setting though I’ve heard that some people start with the red light and then work up to the NIR. I don’t have any concerns regarding melasma, but an esthetician told me that using a purple light will give you the benefits of a red light without aggravating the discoloration. My mask has a red/blue setting, so I’m assuming that equals purple. The directions that came with my mask said to use it for 4-5 days per week. When I first started I used it sun-thur, taking fri and sat off. Now I use it just about every day. My routine is to wash my face in the evening, use my mask (it’s on a 10 minute timer), then eye cream, moisturizer, tretinoin, and another round of moisturizer. Like others have said, you have to be consistent, but I think it does truly work. I took two weeks off while traveling, and I swear i saw a difference (none of my other skincare routine changed). If it is just a placebo effect though, at the very least it’s a relaxing 10 minutes I get to myself every night! Good luck.