It is best not to wear a steel bra when growing up. The steel wire bra is for adult women, because the breasts of adult women have been shaped, and wearing steel wire underwear can entrust the breasts, which is plastic. Wearing it during the development period will have a negative impact on the development of breasts, because the breasts have not yet been finalized. Bras made of steel wire will inhibit the development of breasts and increase the chances of breast diseases, such as mastitis, hyperplasia of mammary glands and dysplasia. It is best to wear a girlish bra or vest during the development period, which can protect the chest from injury and is conducive to the further development of the chest.