I’ve been using modafinil on and off for a couple of years now. I am able to get a prescription for it because I have sleep apnea. I find it hard to focus for long periods on any one task, but I find that when I need to get a lot of work done I can take a tablet and be able to stay on task longer than without the tablet. I don’t take them every day because I can only get thirty at a time and they are not cheap as they are not covered by the PBS in Australia.
I have considered buying them from overseas where I can buy them in larger quantities and with a higher dosage. Even if I was to find that the larger dose was unnecessary I could cut them in half and double the lifespan of the packet. Unfortunately, it seems you can only buy them overseas using cryptocurrency which at this stage has a bit of learning curve involved in using it. So thus far I haven’t tried to source them outside of Australia. Modafinil is probably not for everyone and the government has restrictions on usage, but it does seem to work for me, especially when I want to spend time writing or working on tasks where I want my brain firing on all four cylinders.