Dr. Stephanie Widmer is sounding the alarm about teenagers who are buying a powerful bladder cancer drug online in hopes of adding inches to their height.
The emergency medicine physician said she is deeply troubled by the “heightmaxxing” trend, which has drawn young people — mostly teen boys — to Erdafitinib, a medication also known as ERDA. The FDA approved the drug in 2019 for patients whose tumors carry specific genetic alterations in the FGFR3 gene, and it works by inhibiting a protein that drives cancer cell growth.
“It’s extremely concerning that teenagers are experimenting with powerful cancer medications in an attempt to grow taller,” Widmer said. “These drugs were developed to treat serious medical conditions, not to enhance physical appearance, and taking them without a legitimate medical indication or physician supervision can have devastating consequences.”
One teenager who spoke illustrated both the desperation and the danger behind the trend. Zak, 17, told the outlet he paid $300 for a month’s supply of the drug, which he purchased online. He said he stood five foot five and felt his height was “pretty bad,” leading him to search for anything that could make him taller.
“I was literally saving money every single day,” Zak said. “I was putting money aside from my work and everything just for a medical bill from erda.”
He told the publication that over the course of two years, he did grow several inches. But the gains came at a steep cost: severe joint pain and frequent nosebleeds.
Widmer outlined the medical stakes in stark terms. She warned that unsupervised use of these medications can cause serious side effects, including potentially permanent vision damage, elevated phosphate levels and other metabolic abnormalities.
“We’re talking about adolescents whose bodies are still developing, and exposing them to these risks for a cosmetic goal is particularly troubling,” she added.
Some online claims have pointed to previous research suggesting Erdafitinib may speed bone growth in children and teenagers, but many scientists have disputed this. Doctors are now urging teenagers directly to avoid the drug entirely for height purposes.
Widmer emphasized that young people should focus on their overall wellbeing rather than risking their health for unrealistic physical ideals.
“No amount of additional height is worth risking permanent damage to your vision or other serious and potentially unknown medical complications,” she said.
The National Cancer Institute notes that Erdafitinib is specifically intended for bladder cancer patients with certain genetic alterations, not for cosmetic use by healthy adolescents. The drug’s mechanism — targeting proteins that drive tumor development — makes it a particularly hazardous choice for off-label experimentation.
The trend has emerged from online communities where false claims about height enhancement have spread, creating a market for desperate teenagers willing to spend hundreds of dollars and endure significant physical harm.
Zak’s experience, with its combination of modest success and painful side effects, offers a cautionary example of what doctors now fear could become more widespread as the “heightmaxxing” movement grows.
The FDA has not issued new guidance on Erdafitinib’s off-label use, and medical professionals continue to stress that any cancer medication requires strict physician oversight.