Is Progestin Safe for Humans but not for Animals?

Progestin, a synthetic form of progesterone, is a major component in contraceptives like Plan B and the minipill.(13) Mifepristone blocks a woman’s progesterone receptors, so there’s nowhere for the progesterone to go. Plan B pills release a massive dose of synthetic progesterone into the woman’s body to block ovulation and, if that fails, prevent the embryo from implanting. All official reports and labels for these drugs will say that these pills only cause minor side effects and have no lasting impact on the woman’s health.

However, “veterinarians and dairy farmers have known for years that progesterone (the only natural progestin) typically down-regulates uterine immune functions and prevents the mammalian uterus from resisting infections.”(14) If vets and farmers have known this for years, why aren’t women being told of the risk to their own uterine health? Some women who have taken these pills have even died from severe infections that lead to uterine septic shock, a potentially fatal reaction to a serious infection.