Teenagers Turn to Cancer Medication in Bid for Height
“I don’t know how to put it, but it feels like I’m not in control,” says Zak, a 17-year-old who has spent years experimenting with an off-label drug to increase his stature. Young men on social media are increasingly turning to a practice dubbed “heightmaxxing,” a subset of the broader “looksmaxxing” community, where they trade strategies to combat perceived height discrimination. These teenagers are sourcing erdafitinib—a cancer drug approved for bladder cancer—in the hopes of increasing bone growth before their growth plates fuse.
Medical Risks of Off-Label Erdafitinib Use
Erdafitinib, marketed as Balversa, received FDA approval in 2019 for treating certain advanced bladder cancers in adults. The drug’s prescribing information details severe potential side effects, including limb pain, nausea, diarrhea, and the separation of nails from nail beds. It can also cause excess phosphate in the blood, leading to mineral deposits in soft tissues.
Johnson & Johnson, which markets Balversa, issued a statement expressing concern over reports of adolescents using the medication without medical supervision. The company emphasized that the drug is neither approved nor tested for height enhancement in children or adolescents. Despite these warnings, users like Zak report enduring nosebleeds and debilitating pain, describing sensations where their spines felt bent and ordinary movements, such as stretching an arm, caused intense agony.
The Biological Mechanism Behind Experimental Growth
The interest in erdafitinib stems from its specific interaction with fibroblast growth factor receptors. Adalbert Raimann, a pediatric endocrinologist at the Medical University of Vienna, was an author of a study published in July 2024 in Hormone Research in Paediatrics that documented unexpected growth in two children treated for central nervous system tumors. Raimann explains that the drug blocks the FGFR3 protein, which typically acts as a brake on bone growth. By inhibiting this receptor, the drug may accelerate growth while plates are still active.
However, Raimann warns that the drug’s targets exist in nearly every cell of the body. Because the patients in clinical studies were treated for life-threatening conditions, the risks were deemed necessary. There is currently no data on the long-term consequences of using this cancer drug in healthy, developing children.
Teens Source Dangerous Substances from Overseas Vendors Online
For many, the search for height leads to overseas online vendors and black-market online suppliers. James, a 17-year-old on the West Coast, reported that his fingernails began oozing pus and falling off after he began taking erdafitinib sourced online. He also confirmed experimenting with a cocktail of other substances, including breast cancer treatments like tamoxifen and letrozole, as well as osteoporosis drugs and experimental compounds like SAG 21K.
Pediatricians Warn Against Using Chemotherapeutic Doses for Growth
Pediatricians and researchers point to a growing trend of “DIY healthcare” fueled by social media.
While some parents and teens seek legitimate medical intervention through growth hormone therapy, endocrinologists like Andrew Dauber distinguish between treating a medically recognized hormone deficiency and intervening in cases of idiopathic short stature. Dauber, who has received his first inquiry regarding erdafitinib, maintains that he will not prescribe it for growth, citing the extreme danger of using chemotherapeutic doses for non-oncological purposes.
Common Questions Regarding Heightmaxxing
Is there any medical evidence that erdafitinib makes children taller?
While a 2024 study in Hormone Research in Paediatrics observed growth in two children with tumors, these patients were receiving treatment for life-threatening conditions. Doctors emphasize that the drug is not approved for height, and its safety profile for healthy adolescents remains unknown.
What happens if a teenager stops growing?
Once growth plates at the ends of bones fuse, which typically occurs in early adulthood, natural height increase is biologically impossible. This biological reality drives the urgency felt by teenagers who view their remaining years of puberty as a final window for intervention.
Despite the risks of severe pain, some users remain committed to their experiments. James, who has been hospitalized for a stomach bleed, says his drive to reach a specific height outweighs his fear of the consequences. “I feel like I wouldn’t have to worry about anything, really,” he says. “Everything that’s made me sad and depressed and just not doing OK, it all stems from just my looks and being insecure.”
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