Coca-Cola douches and contraception

Coca-Cola douches were a part of folklore about birth control during the 1950s and 1960s, before effective contraceptive methods were readily available.1 It was rumoured that the acidity of Coca-Cola killed sperm, and the classic coke bottle provided a convenient “shake and shoot” applicator. Recently, an old study from our group confirming the spermicidal effects of various Coca-Cola formulations2 was awarded the 2008 IgNobel prize in chemistry.3 The press releases surrounding our IgNobel award might have repopularised this method, and soft drink douches are apparently still used to prevent pregnancy in resource-poor settings.4 There are, however, many reason why women should not rely on this method.