Serum magnesium levels were noticeably lower (P less than 0.1%). In comparison to the control group, there were 28 women taking Ovral 28 and 65 women who were taking Norlestrin Fe. Those with Lippes loops had concentrations similar to those of 87 women wearing the Lipp loop. Many who underwent Ovral were also found to have lower serum magnesium levels than those who had been fitted with a Lipps loop. The study was conducted at the Post-Partum Family Planning Clinic of University College Hospital in Ibadan, Nigeria. Magnesium is thought to have played a role in the development of thromboembolism in humans.
