Im a rugby player (forward), 19 years old, 86 kgs. need to gain strength and weight, HELP!?

Generally i'd say stay away from that rubbish. Eat lean meat. You say you work out daily then you should grow no problem. But USN, MuscleTech are great products. Just as a sided note: most guys manage fine at club level with weights well below 100kg and some are great at international level... Guys like Martyn Williams (Welsh openside), legendary George Smith and South Africa's Heinrich Brussow never weighed more than 100kg in their careers. You need to balance you body structure with you weight. In rugby skills can counter size on any occasion - as demonstrated countless times between Australia (more skillful) vs. South Africa, New Zealand (more skillful) vs. England, France (more skillful) vs. New Zealand encounters. Good luck though... give those supplements i mentioned a try and don't forget to consult your Doctor first!