Condoms have certain harmful effects when used, the common ones are as follows: 1. If the condom material is substandard and made of poor quality material, the process of sex will produce mechanical damage to women’s vagina, which is only a possibility and does not mean that the poor quality will definitely cause problems, which may lead to women suffering from vaginitis, pelvic inflammatory disease and tubal inflammation; 2. There is a layer of oil outside the condom In order to reduce the mechanical damage to the vagina, this layer of oil on top of the condom, if it is not qualified or if the harmful ingredients are over the standard oil, will make women have an allergic reaction or cause slight poisoning, which will have an adverse effect on women’s reproductive function, depending on the amount and quality of the layer of lubricant on top of the condom, if the lubricant is more and of poor quality, it will be more harmful to women.