use foam in the day
at nite use liguid with retin a
now that they do not make retin a in liquid form any more here is what you do
take the cap from the foam bottle and put about a pea size drop or two of retin a in it then put one dropper of liquid minoxidil in it and mix it very well till it is all one.
then apply it to your scalp
IT IS BETTER TO USE RETIN A MICRO BECAUSE IT IS LESS GREASY
Regards