You uses contraceptives?
http://wiki.smutosaur.us/Herbal_Contraceptive
And I realize I said brown pill when I meant pink pill reverses it, but it's basically the brown pill effects. I've only had one char ever get far enough with the farm to actually get one legit, any other I've resorted to save scumming to get them. They'd be more convenient if you didn't have to go to such lengths to get them, but then only so that you don't have to be leveled enough to clear out the sand-which dungeon. It just seems like an awfully troublesome item for one obviously meant to be more convenient than the pills which you cannot take with you or stock up on for later use, but then your still need the pink one to reverse it anyways. Since it's on the official wiki, it's from the classic game, though I don't remember when or what version it was added; likely when or after the farm became corruptable (not really a word, but whatever).