The Life Extension Foundation had a Forum which has been (quite shamefully I must say) shut down recently, hosting one of the longest thread on the internet on the topic "How to reverse grey hairs". Despite I asked they rejected to leave the Forum as a repository of research. There was an "old Forum" with a section on the same topic which looks still accessible here, maybe you can find some useful information:
http://forum.lef.org...5&p=001&m=22853
I would love to find something effective, I might be re-considering GliSODin but have no evidence it can work.