Medimec made a study, where demonstrated that gold, in spite of being an adequate support as a noble metal core, was in some cases attacked by corrosion from uterine fluids. As a result of this, Medimec has developed a high-purity copper wire with a Gold core, which is absolutely unaffected by corrosion and is also fully biocompatible with the human body. It improves as well the safety of Copper wire as a contraceptive and eliminates any possible allergies to gold.