There are two kinds of methylphenidate.

One is methylphenidate ER which stands for extended release. It’s commonly known as Concerta. The extended release part of it means it lasts for 8 to 12 hours (? Not sure about that technically because it lasts for about eight hours for me).

The other kind of methylphenidate is immediate release and is commonly known as Ritalin. It’s good for a few hours and then wears off pretty quickly

I can’t speak to dosage levels in your country but methylphenidate ER comes in doses like 27, 36, 54. The fast acting one is 10, 20, 30.

It could be that the kind of methylphenidate you’re on is not as effective as it could be. It could be that methylphenidate is not for you. There are so many factors that it’s hard to say what’s happening between your brain and the medication. I wish I had a better answer for you.