* With no break in the dosage, menstrual flow does not initially occur at a predictable time. Most women tend to establish, over a few months, light to heavy spotting at approximately regular intervals. * May cause mastalgia (breast tenderness, pain) and mood swings, as well as panic attacks, anxiety and depression. * Some women may experience abdominal cramps and heavy bleeding. * May cause weight gain. Breast cancer risk Epidemiological evidence on<unk> s and breast cancer risk is based on much smaller<unk> ulations of users and so is less conclusive than that for COCPs. In the largest (1996) reanalysis of previous studies of hormonal contraceptives and breast cancer risk, less than 1% were<unk>  users. Current or recent<unk>  users had a slightly increased relative risk (RR 1.17) of breast cancer diagnosis that just missed being statistically significant. The relative risk was similar to that found for current or recent COCP users (RR 1.16), and, as with COCPs, the increased relative risk decreased over time after stopping, vanished after 10 years, and was consistent with being due to earlier diagnosis or promoting the growth of a preexisting cancer. The most recent (1999) IARC evaluation of progestogen-only hormonal contraceptives reviewed the 1996 reanalysis as well as 4 case-control studies of<unk>  users included in the reanalysis. They concluded that: "Overall, there was no evidence of an increased risk of breast cancer". Recent anxieties about the contribution of progestogens to the increased risk of breast cancer associated with HRT in postmenopausal women such as found in the WHI trials have not spread to progestogen-only contraceptive use in premenopausal women. Depression There is a growing body of research investigating the links between hormonal contraception, such as the<unk> , and potential adverse effects on women’s psychological health. The findings from a large Danish study of one million women (followed-up from January 2000 to December 2013) were published in 2016, and reported that the use of hormonal contraception, particularly amongst adolescents, was associated with a statistically significant increased risk of subsequent depression. The authors found that women on the<unk>  in particular, were 34% more likely to subsequently take anti-depressants or be given a diagnosis of depression, in comparison with those not on hormonal contraception. In 2018, a similarly large nationwide cohort study in Sweden amongst women aged 12–30 (n=815,662) found an association, particularly amongst young adolescents (aged 12–19), between hormonal contraception and subsequent use of psychotropic drugs. Such studies highlight the need for further research into the influence of hormonal contraception, including the<unk>  on women’s psychological health. Weight gain There is some evidence that progestin-only contraceptives may lead to slight weight gain (on average less than 2 kg in the first year) compared to women not using any hormonal contraception.
Progestogen-only pill
Extended cycle combined hormonal contraceptive
Progestogen-only injectable contraceptive
Progestogen-only contraception
Estradiol-containing birth control pill
High-dose estrogen
Levonorgestrel-releasing implant
Male contraceptive