Colchicine-d6 is the deuterium labeled Colchicine. Colchicine is a tubulin inhibitor and a microtubule disrupting agent. Colchicine inhibits microtubule polymerization with an IC50 of 3 nM[1][2][3]. Colchicine is also a competitive antagonist of the alpha3 glycine receptors (GlyRs)[4].