All the size you see in his shoulders bis tris and upper forearms is PMMA. There is no oil in him. PMMA particles are microscopic so therefore you have to suspend it in a carrier like hyaluronic acid or collagen. Over time the body will build up it's own collagen to stabilize the PMMA particles as the carrier dissipates. If done correctly and sparingly it will look totally natural but people get carried away as in most things pertaining to wanting bigger muscles.