Okay went to the derm today for a cyst on the neck simple injection I get this a few times a year,anyways I was telling him about the rogaine foam,he said he likes it and it's much better .. also I asked him his take on retin-a and he said it's great .. it helps absorb the rogaine much better.. he noted using a very little amount as he knows I have a tendency to well over use things.. when using retin-a I suggest using a very tiny amount a pea sized amount .. on the hairline/temples (in my case) or back for some... I apply the retin-a about 1 hour before I apply the foam... I don't use the retin-a 2X a day only once.. as it's way too irritating,I do use the foam 2X a day .. I also asked about azelex (azelaic acid) he said he doesn't use it for hairloss and has no proven record of lowering dht that's what propecia is for.. oh also he said he would mix retin-a LIQUID in a bottle of rogaine (liquid) I assume.. I've never seen retin-a liquid maybe he meant crushing a loniten pill and add it to the kirkland minoxidil or whatever minoxidil you use (not the foam).. I would have gone further and asked more questions.. but I like putting the retin-a cream on the hairline and temples .. by myself.. and applying the foam later on... again please use caution when using the retin-a .. I can't tell you how strong this stuff is.. I used it for 5 days straight while using foam .. and well.. my hair was itching for 3 days .. I used kirkland for 4 years no problem and the foam no problem for about 2 months.. so procede with caution maybe use it every other day or once at night .. but a TINY amount he said it DOES help minoxidil/foam absorb MUCH better! Remember just a TINY BIT of retin-a !!!!!MY hair is back to normal now and will now use the "pea sized amount" as they say to! I hope this helps some people! I was hoping he said azelex.. would help.. but he said it's pretty much a waste for the scalp!