have varying doses from day to day; see formulations for details.) Recently, several pharmaceutical companies have gained FDA approval to package COCPs for the intended use of reducing the frequency of or eliminating withdrawal bleeding. The use of COCP is dependent on desirable effects and risk of adverse events with progestin component and dose of estrogen and progestin component. Estrogen component: Estradiol, Ethinylestradiol, or Estetrol First-generation progestin: Norethindrone acetate, Ethynodiol diacetate, Lynestrenol, Norethynodrel Second generation progestin: Levonorgestrel,dl-Norgestrel Third generation progestin: Norgestimate, Gestodene, Desogestrel Unclassified progestin: Drospirenone, Cyproterone acetate Clinical indications Extended or continuous use of COCPs has been used for many years to treat endometriosis, dysmenorrhea, and menstruation-associated symptoms. Some studies have suggested that women who experience premenstrual-type symptoms during the placebo (hormone-free) week of traditionally packaged COCPs may experience significantly fewer symptoms when placed on extended cycle COCP regimens. More recently, personal preference to avoid menstruation has also become a common reason for use. Personal preference is the most common reason extended cycle or continuous use COCPs are prescribed to adolescents. The Society for Menstrual Cycle Research holds that this use of COCPs does not have sufficient safety studies to justify promotion as a lifestyle choice (as opposed to medical indications), and criticizes what it perceives as negative portrayals of normal menstrual cycles in promotional literature for extended and continuous COCP use. Women's satisfaction with their contraception, compliance in taking the pills on time, and discontinuation rates are not significantly different between traditional and extended cycle regimens. FDA has also formally approved combined pills for acne for specific brands. Oral Contraceptive Pills are also effective in Hidradenitis Suppurativa. There is also limited evidence for benefit of Combined oral contraceptive pill (OCP) as treatment for primary dysmenorrhoea. The evidence from four RCTs is that combined OCPs with medium dose oestrogen and 1st/2nd generation progestogens are more effective than placebo, however the studies were small, Side effects With all extended-cycle COCPs, breakthrough bleeding is the most common side effect, although it tends to decrease over time. In a 12-month study of a continuous COCP regimen, 59% of women experienced no bleeding in months six through twelve and 79% of women experienced no bleeding in month twelve. Extended or continuous use of COCPs or other combined hormonal contraceptives carries the same risk of side effects and medical risks as traditional COCP use. Pill Failure can happen with contraceptive pills and inadvertent pregnancies