The first question to ask, is why? Why are you considering this supplement? A supplement is not intended to fix a crappy diet or poor exercise program. A supplement is intended to be just that, a supplement to your existing good diet/good exercise program. And if you’re eating a well-rounded diet, then there’s really no need for supplementation at all.
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.