Apologies for resurrecting a dead thread, but I found it interesting that some newer papers appear to have duplicated results documented in the original article(s). For example: Topically applied glycyrrhzic acid causes hair removal in rats
. At first, I thought this was just a rehash of the original research, but it looks like the authors, location, and other details are different. Unfortunately, according to the article regrowth after long-term use was only reduced by about 20%, which might be hard to even notice unless used somewhere like the scalp.
I tried mixing up some glycyyhzic acid in a solution of ethanol a while back, but ended up with something that was unusable because it was as hard as a rock at room temperature. Perhaps the ammonium salt would be a more suitable component.
One of the kind of interesting things about the latest report is that the solution was applied with a toothbrush. Although this doesn't explicitly state that hair didn't need to be epilated first, it suggests perhaps an easier method of application than has been tried before.