Oral contraceptives are contraceptives which are taken orally, and act on the body's fertility by chemical means.

Male oral contraceptives remain a subject of research and development, and are not available widely (if at all) to the public. Studies continue of various alternatives, such as gossypol.

Table of contents
1 The Pill
2 The pill as a form of abortion
3 The sexual revolution

The Pill

Female oral contraceptives, colloquially known as the Pill, are the most common form of pharmaceutical contraception, the prevention of unwanted pregnancy. They consist of a pill that women take daily and that contains doses of synthetic hormones (oestrogen and progesterone); the doses are adjusted in synchrony with the menstrual cycle. It is used by millions of women around the world, though the acceptance varies by region: approximately one-third of sexually active women in the United Kingdom use it, while in Japan what amounts to a boycott by doctors making huge profits from abortion has led to the pill being banned for nearly 40 years, and its recent introduction has seen very few women take it up.

Mechanism of action

The Pill works by preventing ovulation, as well as making the uterus less likely to accept implantation of an embryo if one is created, and thickens the mucus in the cervix making it more difficult for sperm to reach any egg. Taken correctly, it is the single most reliable form of reversible contraception, with less than one in 100 women using the pill becoming pregnant in a year of continuous use.

Several different types of 'the pill' exist. Generally, they all have revolve around different formulations of (chemical analogues of) the hormones progesterone and estrogen. Most brands use 20 to 40 micrograms of ethinyloestradiol as the estrogen component and either a fixed or varying (the bi and triphasic pills) amount of progestogen as the progesterone analogue.

Packaging

The pill usually comes in a packet that has days marked off for a cycle lasting about a month. There are usually sugar pills included to fill in the empty days between the end of one cycle and the start of the next so that the woman's body is fooled into undergoing menstruation. It is possible for a woman to skip menstruation and still remain protected against conception by skipping these pills in the cycle. The presence of these pills is still thought to be comforting for the woman as menstruation is a physical confirmation that she is still not pregnant.

Drug interactions

Some drugs reduce the effect of the pill and can cause breakthrough bleeding, or worse, pregnancy (together with unprotected sex, of course). These include antibiotics, barbiturates, phenytoin and carbamazepine. The traditional medicinal drug St John's Wort has also been implicated.

Cautions and contraindications

It also takes at least one complete menstrual cycle for the pill to become effective; many young women have found themselves unexpectedly pregnant during that window.

Serious side effects that would indicate a need to discontinue the pill include: pain or swelling in the thigh or calf, severe headaches, hypertension, dizziness, weakness, vision problems, chest pain or shortness of breath, abdominal pain.

These serious side effects are a result of the pill affecting coagulation, increasing the risk of blood clots causing DVTs (Deep Venous Thrombosis), stroke and heart attacks. This is especially so in women who already have some pre-existing vascular disease, in women who have a familial tendency to form blood clots (such as familial factor V Leiden), women with hypercholesterolaemia (high cholesterol level) and in smokers.

Side effects

Commonly quoted side effects include: weight gain, nausea, headaches, depression, change in intensity of sexual desire and response, vaginitis and vaginal discharge, urinary tract infection, changes in menstrual flow, breast changes, skin problems and gum inflammation

Other risks

The pill slightly increases the risk of breast cancer, while slightly decreasing the risk of ovarian cancer and uterine cancer.

The pill as a form of abortion

In those relatively few cases when the pill prevents the implantation of an embryo, this may be considered a form of chemically induced abortion by those who believe that human life begins at conception. Some therefore reject oral and other chemical contraceptives in favor of natural family planning (the only method of contraception allowed by the Catholic Church) or barrier methods such as condoms. The medical community generally does not consider this to be an abortion at this early stage, and many abortion opponents avoid labeling this as abortion by declaring that human life begins with the implantation in the wall of the uterus.

The sexual revolution

The Pill's development in the early 1960s and FDA approval of the drug on May 9, 1960 was one of the major factors leading to the sexual revolution that occurred later in the decade.