Medical experts are warning of a dangerous new social media trend known as “heightmaxxing”, amid reports that teenagers are taking black market cancer drugs in a bid to grow taller.
Adolescents, primarily teenagers, are reportedly turning to erdafitinib — often referred to online as “ERDA” or “Erta” — a targeted prescription drug approved to treat advanced bladder cancer.
Teenagers are reportedly experimenting with the prescription drug after encountering online discussions suggesting it could increase their height.
“It is extremely concerning that teenagers are experimenting with powerful cancer drugs in an effort to grow taller,” Dr. Stephanie Widmer, a New York-based emergency physician and Fox News medical contributor, told Fox News Digital.
“These medications were developed to treat serious health conditions, not to improve physical appearance, and taking them without a legitimate medical indication or medical supervision can have devastating consequences.”
The drug’s maker, Johnson & Johnson, objected to the practice in a statement to Rolling Stone, emphasizing that the drug has never been approved to stimulate height growth and its safety and effectiveness have not been established for pediatric or adolescent use.
Medical research has documented unexpected growth spurts in children receiving erdafitinib for brain tumors. A 2024 study published in Hormone Research in Paediatrics described accelerated growth in two pediatric patients, while a separate case report documented an adolescent who grew more than 5 inches during treatment but developed serious skeletal complications.
To call:
Doctors warn that these flare-ups do not equate to healthy skeletal growth. Dr. Jessica Gray, a family physician in Lubbock, Texas, warned that forced, rapid growth can trigger dangerous structural problems, including premature growth plate damage and bone fractures.
The drug works by blocking specific cell signaling pathways involved in the growth of cancer cells, Widmer shared during an appearance on Fox News’ “America’s Newsroom.”

These same pathways also play a role in bone development, which may explain why some pediatric patients experienced unexpected growth during treatment.
Widmer noted that height is largely governed by genetics and there are no biological shortcuts. Once the growth plates close near the end of puberty, medications can’t reopen them, meaning older teens who take the compound face catastrophic health risks with no chance of gaining height, she said.
“One of the biggest concerns is that these medications can cause serious side effects, including potentially permanent visual damage, elevated phosphate levels and other metabolic abnormalities,” Widmer said.
“We’re talking about adolescents whose bodies are still developing, and exposing them to these risks for cosmetic purposes is particularly troubling.”

Other warning signs and side effects related to the drug include bone pain – especially in the hips or knees – as well as mouth sores, loose nails, and skin disorders.
This trend has also raised concerns about the influence of social media on adolescents’ decisions about their health. Widmer noted that online discussions about physical appearance and self-improvement can expose young men to potentially harmful practices lacking medical evidence.
“Parents need to understand that this goes beyond teenagers being insecure about their height,” the doctor said.
“We’re talking about young people who may be getting prescription cancer drugs and experimenting with them outside of medical supervision. If a child has concerns about their growth, that conversation belongs in a pediatrician’s office, not on an Internet forum.”
Doctors advise parents to watch for symptoms such as unusual joint pain or unexplained physical changes, and to talk to their children if they suspect they are using medications obtained online.
Adolescents concerned about their height or growth should consult a pediatrician before considering any medication.
“We should be encouraging teens to prioritize their health, not teaching them to play with it,” Widmer said. “No additional height is worth risking permanent damage to your vision or other serious and potentially unknown medical complications.”
Gn Health

