ive been using the foam for mostly the front, sides and a little on back for about 5 months now? I havent gotten any bad sides that I know of and honestly I dont think i've seen much of a difference at all yet (my right side possibly got better? can't really say not sure). I really havent inspected my back so far so I cant tell you about the vertex. I told myself I wasn't going to obsess and just stick with it for 9 months.. I will take "after" pictures and do the inspecting in another 4 months.
I'm 25 and I don't even know if I have "male pattern baldness" or what.. I first started to notice the thinning at 23 and it progressed ever so sliiightlyyy and it's pretty much been the same since then now... maybe it's just something that happens with age. I mean I have a full head of hair with no temple recession but it's thinning a bit in the front center. I've seen people with temple recession who seem to have more density than me in the front center. I just want a little more density in the center the way I had it normal at 22. If this foam does not work I may even consider a little bit of hair transplant just to fill in that density a bit.. I don't know what else to do.