Analysis of information sources in references of the Wikipedia article "Progestogen-only pill" in English language version.
Development of the minipill, which contains only a progestin, was another result of concerns over the thromboembolic side effects of combination oral contraceptives.36 This development was also driven by the expectation that lower steroid doses would diminish effects on the metabolic and reproductive systems, lessen complaints about nausea and headache, and improve compliance (because it offered a regimen of continuous pill taking rather than the cyclic regimen of earlier pill formulations).37 Syntex was the first to introduce a 0.5 milligram chlor- madinone acetate minipill in 1968 in France, although this pill was withdrawn from the market in 1970 when long-term animal toxicity tests for the FDA revealed the occurrence of breast nodules in beagles.38 Nevertheless, other manufacturers began to pursue minipill development using their own progestogens, and since 1970 a variety of compounds have been introduced.
Ovulation may be suppressed in 15–40% of cycles by POPs containg levonorgestrel, norethisterone, or etynodiol diacetate, but in 97–99% by those containing desogestrel.
Distribution and Use of the Minipill. [...] Progestogen & Dose in mg: d-Norgestrel 0.03. Manufacturer: Schering AG. Brand Names: Microlut, Nordrogest. Where & When First Marketed: Federal Republic of Germany 1971.
The progestin-only pill was introduced in 1972.
In 2002, a POP containing desogestrel 75 ug/day, a dose sufficient to inhibit ovulation in almost every cycle, was introduced in Europe.51
Chlormadinone acetate was the first minipill contraceptive to be marketed, in Mexico during July 1968. This compound was removed from clinical use in February 1970 because it produced nodules in the breast tissues of beagle dogs [...]
