These were sold under various Dr. Somebody’s brands.
Even in the 1800’s, reputable doctors knew arsenic was highly toxic, and they tried to warn people away from these products. But for a time, the pallor and waxy, death-like skin arising from arsenic poisoning was a beauty ideal.
At least dozens of deaths were attributed to the use of arsenic wafers as a beauty aid, and the true number might be much greater than anyone knows.
They were often advertised as being safe, as seen on this box.
Pennyroyal is also mentioned and also a rather famous abortifacient. It has the added benefit that pennyroyal tea is actually rather tasty, as opposed to (I imagine) quite a few of the other options.
Thankfully these are just cosmetic.
Somewhat less fortunately, arsenic will kill you many ways, both slow and fast, but it’s not likely to uhm… Create regular periods.