Teenage boys across the country are experimenting with the prescription cancer drug erdafitinib – marketed as a treatment for advanced bladder cancer – in an effort to increase their height. The practice, dubbed “heightmaxxing,” has sparked alarm among medical experts.

Local physicians raise the alarm

Dr. Jessica Gray, a family physician in Lubbock, Texas, warned that forced, rapid growth can cause premature growth‑plate damage, bone fractures and other structural problems. “Parents need to understand this goes beyond teenage insecurity,” she said. “If a child is concerned about height, the conversation belongs in a pediatrician’s office, not on an internet forum.”

National medical concerns

Emergency‑medicine physician Dr. Stephanie Widmer, a New York City‑based Fox News medical contributor, called the trend “extremely concerning.” She emphasized that erdafitinib was developed to treat serious medical conditions, not to enhance physical appearance. Unsupervised use can lead to permanent vision damage, elevated phosphate levels, skeletal pain, mouth sores, loose nails and skin disorders.

Johnson & Johnson, the drug’s maker, reiterated that erdafitinib has never been approved to stimulate height growth and its safety for pediatric use has not been established.

Scientific background

Research has documented unexpected growth spurts in children receiving erdafitinib for brain tumors. A 2024 study in Hormone Research in Paediatrics described accelerated growth in two pediatric patients, while a separate case report noted a teenager who grew more than five inches but suffered serious skeletal complications.

These growth effects are linked to the drug’s mechanism of blocking cellular signaling pathways involved in both cancer cell proliferation and bone development. However, Dr. Widmer stressed that height is overwhelmingly governed by genetics, and once growth plates close near the end of puberty, medications cannot reopen them.

Advice for parents

Doctors urge parents to watch for symptoms such as unusual joint pain, unexplained physical changes, or vision problems, and to discuss any height‑related concerns with a qualified pediatrician. “We should be encouraging teenagers to prioritize their health, not gambling with it,” Dr. Widmer said. “No amount of additional height is worth risking permanent damage.”

Original reporting: Fox News (HLL/CB) — read the source article.