The latest and greatest performance enhancer, if you've been living under a rock, is deer antler velvet. On the surface, it seems like it could make sense. The coating on the antlers of young male deer that contribute to the growth of that part of their body could help athletes. First, the NFL prohibited Oakland Raiders coach Hue Jackson from endorsing it. Now, according to SI.com, Major League Baseball is warning players about using it.
A systemic review on human interventions makes note of a study conducted on patients of osteoarthritis (Edelman et al. 2000; cannot be located online) which found improvements in joint pain symptoms relative to baseline in the Velvet Antler group and not placebo, although a lack of information on blinding and randomization precludes results that can be drawn from this study.