Insulin-like Growth Factor 1 (IGF-1) is an anabolic molecule which appears to induce growth of the antlers themselves, although testosterone may be the primary growth factor. Currently, there is no evidence that serum IGF-1 is increased following Velvet Antler ingestion with one study using 1.5g of Velvet Antler for 11 weeks failing to increase serum IGF-1.
More recent tests (Slievert, 2003) confirm deer antler velvet’s effects on muscle strength and endurance. In a randomized, double blind, placebo controlled experiment, 18 males entered a 10 week strength training program. Those who took deer antler velvet showed an increase in maximal aerobic capacity, an increase in strength in the bench press and leg squat, and decrease in body fat relative to the placebo group.
Researchers believe that the imbalance between cartilage erosion and regeneration in osteoarthritis suffers is caused by a lack of glycosaminoglycans. Glycosaminoglycans play a vital role in the structural integrity of cartilage. The compound appears to inhibit enzymes that deplete cartilage nutrition. Chondroitin sulfate molecules are long chains of sugars and sulfur that create tiny spaces filled with fluid. These spaces protect and cushion joints.
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.