My cousin is a producer and swears by this stuff. He makes both a human and canine version under the brand name Caneva (in Canada). Mostly sold for joint issues and bone regrowth support in osteoporosis.
[url=http://www.caneva.ca/]CanEVA - Home[/url]
I haven't tried it, so can't comment on the effectiveness, but I have met the elk and seen his operation. It is a renewable resource (elk grow and shed antlers annually and are not harmed by the farmers removing the antlers from them while in a young, velvet-covered stage). It is totally natural - they live in beautiful woodlands and pastures, are only fed haybales during the winter, otherwise they graze for their whole lives. I have eaten his elk burgers and sausages - they are awesome!
I review my father-in-law making Chinese home cures that consolidated little deer tusks. The major ordeal was that it needed to have the velvet on it. Evidently its been utilized within Chinese prescription for quite a while. What impact it has, I don't have the foggiest idea, however this stuff was just given to grown-up guys.