Elk velvet antlers have been shown to contain chondroitin sulfate. This has a growth-promoting effect on cells throughout the body, which helps with recovery. This includes cells in the gut. It is believed that cartilage proteoglycans regulate water retention and differentiation and proliferation of chondrocytes inside cartilage tissue. Four types of collagen (I, II, III, and X) have also been identified in deer antlers. The collagen may provide benefits including rebuilding damaged parts of the GI tract, skin and joints. This might be beneficial for preventing or helping to treat leaky gut syndrome, which contributes to widespread symptoms.
In rats undergoing left coronary artery ligation, those with heart failure were given either Velvet Antler (Deer) or Captopril as active control for 4 weeks with a third group given water.[17] No significant changes in cardiac structure was noted with either Velvet Antlers or Captopril (with the heart tissue being enlarged after heart failure) although left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) appeared to be improved in both treatment groups to approximately the same degree and the increase in serum Brain Natiuretic Peptide (BNP) that occurred with heart failure was attenuated the same degree in both interventions.[17]

A systemic review on human interventions[25] 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.