I have read studies that show spearmint tea lowers testosterone levels in women. When I had my hormones levels check that was the only thing off... testosterone still in the "normal" range (which is like 6-90 units), but at the high end (mine was in the eighties). So I try and drink my tea. When I drink it daily, I can tell it helps shorten my cycle. Sucks that it is hot and humid outside... not exactly the best time to be drinking tea, but I've been icing it down and it's pretty good.
http://www.ncbi.nlm.nih.gov/pubmed/1...t=AbstractPlus
Hope that helps!!