not more , it just makes the come-up come faster, and a quicker come-up, so you might get the impression its stronger..
In my experience it might make it come on a little bit faster (like I'm talking 5-10 minutes faster than if you have food in your stomach?), but not necessarily harder. And in my experience you're much more likely to get nauseous or even throw up if you take it on an empty stomach.
Back when I was raving every weekend I'd always eat a substantial amount of something nutritious about 2-3 hours before rolling so that I have enough energy to get me through the night![]()