I had a friend that liked the effects of Modafinil, but would complain of bad headaches every time they took some. Even less than 1 quarter of tablet would be enough to produce the bad effects.

Is that something that happens just to some people or is there a way to avoid the headaches?

I'm curious about trying, but since I used to suffer migraines (not anymore fortunately) I am worried that I will have headaches or trigger a migraine.

I suspect that his headaches might have been due to dehydration - Modafinil does indeed make me pee a little bit more/more often, but since I am drinking water constantly I don't consider this a negative side effect and I also don't suffer consequences such as headaches. But I am fortunately healthy, fit and relatively young (30) and only very rarely suffer headaches. Before I decided to use Modafinil I did research its side effects as well as potential risks and every couple of months I check the newest studies to see if new data came up - TLDR: some people indeed experience some headaches and/or nausea and in very, very rare cases some people experience pretty bad allergic skin reactions. But then again some people die of peanut allergy so... Modafinil has been there since the 70s, there are even some studies about its long-term use (10+ years) and its side effects and it looks pretty chill. I think the English Wiki Page for Modafinil is pretty well researched and a good place to start if you want to read more: https://en.wikipedia.org/wiki/Modafinil

I'm also a frequent modafinil user (maybe 4/7 days a week) and luckily haven't experienced side effects. I also drink tons of water throughout the day so that could definitely be a factor.

Interesting, thanks!

Definitely will need to read more about it before considering trying it.