I’m on the same. I’ve personally found they work best when you can’t feel them. I’ve had days where I can’t remember if I took them. However, on those days, if I look back over it, I can tell the effect.

The best method (I’ve found) is slow, but effective. Titrate up, around every 2 weeks to a month (under doctors guidance). Each time, you’ll initially feel it, then it will fade. Once you have a slight jittery feeling left behind, you’re about there, if it’s strong, you’ve over shot, ask to go down 1 dose. The last jitter will fade off over a few months. This is your maximum optimal dose.

Interestingly, the higher doses will likely feel more productive, this is a false feeling. While the high dose will help focus, it has begun to disrupt other mental systems. The overall effect is a net loss, compared to a slightly lower dose. This is also what happens to a normal brain on the drugs. They feel more focused and productive, but, when actually measured, are worse off than unmedicated. We get a long term boost, but it’s not unlimited. We hit the same limit, eventually.