According to an article published by Business Insider, between 20 to 40 percent of professional MLB and NFL athletes admit to purchasing and using deer antler spray (also called “deer antler velvet”). They hope to benefit from its performing-enhancing effects. (1) Some famous athletes turn to deer antler spray in hopes of promoting growth of new tissue cells or gaining strength due to more easily putting on lean muscle mass.
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.