Depends on how much, but in general you aren't going to "feel" any different for a few weeks.
Weights will start to feel lighter, you will have more endurance and start to fill out a little.
It's not as drastic as people think, unless you are using some serious dosages.
I typically start to "feel" it around week 2-3.
After the first 5-10 days i start getting some serious boners, if i'm using orals. The wind blows the right direction and Mr. Happy gets excited. My GF notices it too, it increases your libido and gives you rock hard boners, which she never complains about.
