Wow! I've actually used T-Gel because I used to get dandruff really bad as a teen and it was pretty effective. It's horrifying to know what it really was.

It says coal tar right on the bottle. And it smells awful. And it can be pretty effective.

I used it briefly and then researched it and it seemed like at the time (mid-2000s), nobody could say which of the menagerie of components of the coal tar was actually the effective one.

I stopped pretty much at that point.

Try using something mild like baby shampoo, use tiny amounts of it, and less frequently. Works a lot better in my experience.

It's not true, fortunately. See my reply to the grandparent.