Modern copper-containing contraceptive intra-uterine devices (IUDs) typically comprise a solid plastic frame loaded with copper wire and/or copper sleeves. Although they are very effective (annual pregnancy rates generally below 1%), some women discontinue their use within a year after insertion because of excessive bleeding and/or painful periods (4-15%), or because the device has been spontaneously expelled (2-8%). GyneFix (Contrel) is a new IUD approved for up to 5 years of use. Its manufacturer claims that the device produces fewer unwanted effects, and is less likely to be expelled, than conventional IUDs because it does not have a plastic frame (a frameless device). Here we assess these claims.