In the beginning I used a regular shampoo and crushed generic caffeine pills and aspirin in it, and that worked like a charm. But it was too much of a hassle so for a couple of years I've been using Alpecin caffeine shampoo, and I crush the aspirin in a regular local coconut shampoo brand. I wash once with the alepcin shampoo and once or twice with the aspirin shampoo.
So caffeine shampoo is Alepcin c1
The aspirin is over the counter generic aspirin and I crush it in a locally made herbal shampoo with coconut oil.
Can you not mix aspirin and caffeine in the same shampoo?