Here’s part 1

The basic question: What’s causing these Rogaine flakes?

1. Dried Rogaine?
2. Dandruff resulting from an irritated scalp?

It appears—at this point still far from 100% on this—but, it seems the answer might be number 2 and that Rogaine liquid (not foam) contains a substance called propylene glycol. The liquid version’s propylene glycol apparently helps the drug penetrate into the scalp. For some folks, though, it’s an irritant. A lot of people also seem to mention itching along with the flaking.

In my case, I’m not experiencing itching. Maybe I used good shampoo or something…(I use Nizoral, by the way).

I don’t know.

But, this info seemed to be pretty credible. If this is something you’re dealing with, I’d say searching for info concerning propylene glycol vis a vis dandruff flaking would be a good place to start.