Viral ‘heightmaxxing’ trend has teen boys taking cancer drugs to grow taller, doctors warn of risks

Doctors are warning that teenage boys are reportedly using black-market erdafitinib, a cancer drug, in an online trend called “heightmaxxing”. The drug is approved for advanced bladder cancer, not for increasing height, and its safety and effectiveness have not been established for children or teenagers.

Medical reports describe unusual growth during treatment, but doctors say this does not mean healthy development: one teenager grew more than five inches and developed serious skeletal complications. Risks include vision damage, metabolic problems, bone pain and fractures; doctors also stress that height is largely genetic and the drug cannot reopen growth plates once they have closed.