In the present study, we investigated the physiological and potential performance enhancing effects of New Zealand Deer Antler Velvet (NZDAV) supplementation in men. Deer antler velvet reportedly enhances immune function, improves athletic performance, muscle recovery after exercise, enhances sexual functioning in both men and women, improves disease recovery, enhances cardiovascular function, and may be a superior source of insulin-like-growth factors for manufacturers. While there have been several studies aimed specifically at the potential health benefits of deer antler velvet using in-vitro and in- vivo animal research models (Clifford et al. 1979; Wang et al. 1988a; Wang et al. 1988b; Zhang et al. 1994; Zhou et al. 1999; Allen et al. 2002), to date there are no published placebo controlled human clinical trials on physiological function and performance. Thus, the primary purpose of this study was to investigate what effects 1350 mg of NZDAV supplementation twice a day had on body composition, maximal strength, maximal aerobic power, and maximal power output before and after 10 weeks of resistance training in men aged 18 to 35 years old. In addition, comprehensive blood profiles were taken to evaluate if any detrimental effects occurred over the 10-week treatment period in blood lipids, and liver and kidney function.