He may experience increased acne and mood swings. He needs to take Clomid to combat the estrogen production associated when having too much testosterone in the body; if not, he may get "Bitch Tits". He needs to cycle in a pyramid fashion..tapering off at the end of the cycle. He shouldn't cycle for more than 3 months at a time.
If he is looking for fast bulk and then maintain the bulk, he should probably opt for a testosterone cypionate and propionate stack.
However, all of this shit can have serious side effects and I highly recommend against it for a few reasons:
1. Very expensive in the US
2. Buying in the black market can be dangerous because of the many counterfeit roids out there that can actually kill you
3. It is VERY illegal and in my opinion, not worth losing your career or life for it.
4. Results are only temporary. Just work out hard and take good supplements.
Also, he needs to bulk in the winter and cut in the summer. There are specific things he needs to take if he wants to get maximum results. He may be cycling two substances that do not complement each other.
This post reflects an opinion based off people that I have spoken to in the gym. I have never done this stuff, will not touch it and highly advise you DON'T do it.