On the subreddit “nattyorjuice” there are several threads dedicated to Brain (most recent
here), and everyone screams “juiced!”, but the users there are paranoid people who consider doped every trainer with visible pecs and abs. On a more impartial assessment, his stats (200 cm – 110 kg – ~9% bf) give a FFMI = 23.8, well below the natural limit of 25; therefore, he can have attained his physical shape naturally. Of course, since there aren’t anti-doping tests on IG and his popularity is related to his fit body, he has nonetheless an incentive to use PEDs – but it is far from certain that he is on juice. He doesn’t look to have the usual signs of steroid abuse, so I agree that he is likely natural.