In the 1960s, the minimum amount necessary to control ovulation was not well understood, so the doses were heavy. Because of this, there was a high incidence of side effects such as thrombosis. In Japan, as a result, considerable numbers of women use medium-dose pills as a form of birth control. The problem, of course, is that this puts a heavier strain on their bodies than would the low-dose counterparts. Ill people, for instance, shouldn't use it.
Some people experience nausea or simply find it incompatible with their bodies.
It should be used under medical supervision, after consulting with a doctor, and people who use it should get a blood test and have their blood pressure checked at least once a year. If women can exercise control over birth control, they gain freedom in terms of their sexual behavior, and some people say their sexuality should be constrained by the fear of pregnancy. It is only natural that people who favor giving men the right to regulate women's sexuality would be opposed to liberalizing the pill. We also feel pressure from those who fear that allowing the pill would lead to a further fall in Japan's birth rate. The Ministry refuses to give approval in spite of the fact that there is a drug that fills this need.