I don't know if Regumate is a legal substance but I used it between
competitions a few years back. A word of caution: Do NOT get it on your
skin, as even a drop on the skin of females can completely disrupt the
menstrual cycle. I don't know what it does to men, maybe makes them talk
funny for a day or two <g>.
This idiosyncrasy not be in the literature but some of the female vet techs
relayed it to me because no one had warned them.