Extended cycle combined hormonal contraceptive Extended cycle combined hormonal contraceptive Extended or continuous cycle combined oral contraceptive pills are a packaging of combined oral contraceptive pills (COCPs) that reduce or eliminate the withdrawal bleeding that would occur once every 28 days in traditionally packaged COCPs. Extended cycle use of COCPs may also be called menstrual suppression. Other combined hormonal contraceptives (those containing both an estrogen and a progestin) may also be used in an extended or continuous cycle. For example, the NuvaRing vaginal ring and the contraceptive patch have been studied for extended cycle use, and the monthly combined injectable contraceptive may similarly eliminate bleeding.
Estrous cycle that releases sex hormones including estrogens and progesterone. However, species vary significantly in the detailed functioning. One difference is that animals that have estrous cycles resorb the endometrium if conception does not occur during that cycle. Animals that have menstrual cycles shed the endometrium through menstruation instead. Another difference is sexual activity. In species with estrous cycles, females are generally only sexually active during the estrus (oestrus) phase of their cycle . This is also referred to as being "in heat". In contrast, females of species with menstrual cycles can be sexually active at any time in their cycle, even