I did a cycle with only 10mg a day. When I took the 10mg at once, I could feel the lethargy. It was bearable because I preloaded with 4ad, but it was noticeable. When I split it into 2 - 5mg doses 12hrs apart, the lethargy was not noticeable and, in fact, I felt great on it. So, DON'T DO IT, you're too young. But if you do it in a couple of years, you may have to experiment to see how it works best for you.
dd