halo is a 17aa oral steroid. it is one of the most toxic drugs besides anadrol. usually it is used by bodybuilders precontest because it increases androgens without aromatizing therfor you won't get any bloat and your muscles if lean enough will appear alot harder. it is also uised by powerlifters because halo increases strength dramatically without weight gain. this is not a drug to tinker with because it also invreases aggression darmatically that is why they call it the angry ppill
it seemed to me they were good for strength , and especially good for hardening up, not all that good for mass , at all. as for toxicity, these guys advice is probably better than mine, i had no sides at all except for a short temper.