Interesting, I'm also like that with many meds. Currently using Modafinil, and it's the same there. 1/4 or 1/2 was the right dose for me initially, now I can take a whole one. Supposed dose is two whole ones, always, from the start.
Many meds come with an insanely high dosage. The worst is Venlafaxine - the smallest dose give many people a terrifying inner pain that lasts for a long time, easily the worst day of your entire year. Against all recommendations, I now start with like 5 - 10 % of any new stuff, and only if that has no effect at all, I go for like 50 %. With Modafinil, that method proved already quite daring.
What's your experience with Modafinil? I find that it works pretty well, but I am working on getting alternatives to try soon.
Take into account that Modafinil is very unsafe in combination with many other drugs, such as all benzos. I don't know how much time you need to be safe, but I'd wait at least a whole day (48 hours after taking Modafinil) before using something that is definitely unsafe with it.
Did you also get it through a EU prescription from a semi-shady, but legal site?