There is evidence that polyacrylamide hydrogel will degrade in human body, but the exact degradation products are still unknown and need further exploration. Whether the material is compatible with human tissues for a long time, whether there may be chronic rejection, and whether the degradation products are toxic or carcinogenic are not rigorous answers.
The biggest problem is that once injected into the body, it cannot be completely removed. When there are complications such as infection, pain and induration, it is difficult to fully recover. Therefore, the method of injecting polyacrylamide hydrogel for breast augmentation has not been adopted in developed countries such as the United States and Europe. Although the product has been registered with American patents and trademarks, it cannot pass the drug safety inspection of FDA. It can only be used in animal experiments, and it is considered illegal to apply it to human body.