<unk> s or Progestin Only Pills (POP) are contraceptive pills that only contain synthetic<unk> s (progestins) and do not contain oestrogen. They are colloquially known as mini pills.
Although such pills are sometimes called "Progesterone Only Pills," they do not actually contain progesterone, but one of several chemically related compounds and there are a number of<unk>  only contraceptive formulations.
Progestogen only pill
Male contraceptive
Combined oral contraceptive pill
Norelgestromin and ethinyl estradiol transdermal system
Oral contraceptive
Etonogestrel and Ethinyl Estradiol Vaginal Ring
Emergency contraception
Norgestrel/Ethinyl estradiol