There are three main types of oral contraceptive pills: progesterone-only oral pills, combined oral pills, and emergency contraceptive pills. The most popular among them are combined oral pills, based on a combination of estrogen and progesterone synthetic hormones. They seem to be advantageous for many women.
However, there are certain cases when a woman wants to use oral contraception but she has allergic reactions to estrogen use. In these cases progesterone-only oral pills can be a perfect solution. Progesterone-only oral pills are also called mini-pills, and do not contain estrogens.
The mechanism of their action consists in the thickening of the cervical mucus, so that the spermatozoid cannot penetrate into the uterus. Concomitantly they perturb the move of the egg through the fallopian tubes. The effectiveness of progesterone-only oral pills is slightly lower than that of the combined oral contraceptives (about 95%).
The most important advantage of mini-pills comparing to combined pills is that they can be used by women who cannot take estrogens. For example, breastfeeding women cannot take estrogens, as they decrease the flow of milk. Women who suffer from hypertensive syndrome or those who are over 35 years old and still smoke are not recommended to use estrogens, as they increase the risk of thrombosis and stroke. Women with serious cardio-vascular disorders should be cautious using estrogenic hormones.
So, for certain cases mini-pills may constitute an optimal alternative. Other important progesterone-only pills benefits include decreasing the risk of pelvic inflammatory diseases, decrease of breast and cervical cancer risk, avoiding typical side-effects of combined pills, decrease of menstrual blooding, they do not interrupt the sex act, and contraceptive effect is absolutely reversible.
The discontinuing of mini-pills use will totally reestablish fertility immediately or after a few months. Also the pills will not affect the health of the future child. The disadvantages of the progesterone-only oral pills are relative. Some women may consider it difficult to take pills every day, strictly at the same time. Irregular use of the pills may considerably decrease their effectiveness, punctuality being essential.
When using a combined oral contraceptive; use the allowable delay interval of 12 hours, mini-pills must be taken strictly at the same hour every day, with the admissible delay of maximum 3 hours. Mini-pills do not protect from sexually transmitted disorders, so women who are exposed to infection risk must use supplementary a barrier method (condom).
The more serious disadvantages of mini-pills include an increased risk of ectopic pregnancy and functional ovarian cyst. Progesterone-only pills side effects include irregular or heavy bleeding, spotting, missing periods (amenorrhea), decrease of the libido (sex drive), abdominal pain, mood changes, and so on. Usually most of the side-effects are temporary and diminish or disappear after two-three months of regular use.
Though progesterone-only oral pills are not as popular as combined pills, but they may be an optimal solution for women who cannot or do not want to take estrogens.