Every once in a while a bodybuilding guru will tout special benefits of high niacin supplementation. One past study showed it had up to a 600% increase in growth hormone. This may sound wonderful, but niacin also reduces FFA (Free fatty acids). Why should we care about that? Well there seems to be a link in it reducing FFA and actually reducing performance. In other words, Niacin may increase growth hormone, but your workouts may suffer. The doses also used are very high and near the FDA toxicity levels for Niacin. In summary, Niacin shouldn’t have much (if any), positive effect overall to a bodybuilder’s muscle gains.