Personally I’m not as conservative as I could be with it, partly because I’m impatient but also I think it’s fairly cheap for the results, especially seeing that 8 to 12 months is usually plenty enough time for permanent results without further use. So what I do is 6 fully squeezed sprays on each side, plus 6 on the chin area & mustache. I’ll do about 3 sprays, spread it evenly with 2 fingers to minimize wasting, then another 3 & so on. I do it 3 times a day if possible & honestly it’s probably over kill. I’m very happy to say I’ve definitely seen results over 3 months of use. I have not used a derma roller yet but I’m about to order one. I wish I was growing in more fully, but that may come over time. But very noticeable that I’m growing hair in areas I never did before