Doctors are issuing an urgent warning about a dangerous “heightmaxxing” trend in which teenagers are taking a cancer drug in the hope of becoming taller.

The medication, erdafitinib—often referred to online as “ERDA” or “Erta”—is primarily being used by teenage boys seeking extra height. It is approved for treating certain types of bladder cancer.

Reports indicate that some teenagers have obtained erdafitinib after seeing social media claims suggesting the drug can trigger additional growth.

Medical professionals strongly advise against using it without a prescription and close supervision, warning that the medication may cause permanent health problems while offering no proven height benefit.

Dr Stephanie Widmer, an emergency medicine physician in New York City, told Fox News Digital: “It’s extremely concerning that teenagers are experimenting with powerful cancer medications in an attempt to grow taller.

“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.”

Experts say possible complications include damage to developing growth plates, bone fractures, severe pain and injury to internal organs.

Erdafitinib, marketed under the brand name Balversa, has been approved by the Food and Drug Administration (FDA) for certain patients with advanced bladder cancer.

Doctors warn that teenage boys are taking a bladder cancer drug in the hope of gaining extra height

The drug works by blocking a protein involved in the growth of bladder cancer tumors, as well as other cells in the body, thereby slowing tumor development.

Some earlier research has raised the possibility that erdafitinib could accelerate bone growth in children and adolescents. However, scientists have challenged those findings, and there is no established evidence that the drug safely increases height.

Available only by prescription, erdafitinib has been associated with a range of side effects, including vision problems, nosebleeds, changes to the skin and nails, and intense muscle and bone pain.

Despite those risks, reports suggest some teenagers have bought the medication from overseas online sellers.

Johnson & Johnson manufactures the drug, which was approved in 2019 for bladder cancer patients whose disease has progressed after at least one previous treatment.

It is used specifically for urothelial carcinoma, the form of bladder cancer responsible for roughly 90 percent of the 84,000 cases diagnosed in the United States each year.

According to Rolling Stone, a 17-year-old identified only as Zak spent $300 on a one-month supply after deciding the drug might help him grow taller.

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Zak said he gained several inches between the ages of 15 and 17 while taking erdafitinib, but also experienced severe joint pain and repeated nosebleeds. The symptoms became so serious that he worried he might require hospital treatment.

It remains uncertain whether erdafitinib can increase height, while side effects including nosebleeds and severe pain are well documented

“I was literally saving money every single day. I was putting money aside from my work and everything just for a medical bill from erda,” he told Rolling Stone.

Another 17-year-old, identified as James, told the publication that his fingernails turned yellow and began producing pus after he started taking the drug. He claimed to have grown approximately three inches within two months of beginning erdafitinib in late August.

“I was five foot five, so it was pretty bad. So then I just knew that there had to be something that could make me taller,” he said.

Johnson & Johnson told the publication that erdafitinib “has not been approved to increase height, and its safety and effectiveness have not been established for that purpose or for use in any children or adolescents.”

Doctors likewise stress that it is still unknown whether the drug can meaningfully increase a teenager’s adult height.

The online claims appear to be linked to a 2024 study published in the journal Hormone Research in Paediatrics. Researchers observed unexpected growth spurts in children taking erdafitinib for tumors affecting the central nervous system.

During puberty, bones lengthen at growth plates—areas of cartilage near the ends of bones. Growth is regulated in part by FGFR3, a naturally occurring substance. The researchers proposed that erdafitinib’s ability to block this pathway might have contributed to the observed growth spurts.

Dr Adalbert Raimann, a pediatric endocrinologist at the Medical University of Vienna in Austria and a co-author of the study, has nevertheless warned that using the drug carries significant dangers.

“And those receptors we’re targeting with ERDA, they’re present in basically every cell,” he told Rolling Stone. “So we have no idea, not in adults and especially not in kids in this developing system, what we are doing in five to 10 years.”

Once puberty is complete, the growth plates close permanently. As a result, erdafitinib is unlikely to alter bone growth after that stage.

Widmer said: “One of the biggest concerns is that 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.”

Widmer added: “We should be encouraging teenagers to prioritize their health, not teaching them to gamble with it.

“No amount of additional height is worth risking permanent damage to your vision or other serious and potentially unknown medical complications.”

Two men were scheduled to be executed in the United States on Thursday, including a Texas father convicted of beheading three young children in his care in a 2003 crime that shocked the community of Brownsville near the US-Mexico border.

In Oklahoma, James Pavatt was also scheduled to die by lethal injection for the murder of an advertising executive, the estranged husband of a woman with whom Pavatt was having an affair.

Prosecutors said Pavatt carried out the killing alongside the woman, who remains the only female inmate on Oklahoma’s death row.

The US was on course to record more than 40 executions for a second straight year, with Florida accounting for much of the increase as the death penalty receives renewed scrutiny.

Last week, California Gov. Gavin Newsom said he would commute hundreds of death sentences before leaving office. Experts have described the move as potentially the largest mass clemency action in US history.

Pavatt, 73, was scheduled to be executed at Oklahoma State Penitentiary in McAlester.

John Allen Rubio, 46, was scheduled to be executed later in Texas at the state prison in Huntsville.

3 young children beheaded in Texas

Rubio and his girlfriend, Angela Camacho, were accused of killing Julissa Quesada, 3; John E. Rubio, 14 months; and Mary Jane Rubio, 2 months. The children were found in the squalid, windowless Brownsville apartment the couple shared.

Camacho pleaded guilty and is serving a life sentence.

Rubio’s first capital murder conviction was overturned on appeal after the court ruled that statements made by Camacho had improperly been admitted as evidence during his trial.

At his second trial, Rubio again pleaded not guilty by reason of insanity. He was convicted once more and sentenced to death.

Court records show Rubio was not the biological father of the two older children, but he raised them as though they were his own.

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Rubio at times claimed the children were possessed and said he was the “chosen one” destined to save the world. Defense experts diagnosed him with paranoid schizophrenia, but prosecution experts rejected that conclusion.

Defense experts testified that Rubio’s violent childhood, “toxic” parents, drug use and exposure to prostitution had impaired his development.

The apartment building where the children were killed was later demolished, and the site was converted into a park and community garden.

Oklahoma advertising executive killed in garage

Pavatt was convicted of first-degree murder and conspiracy to commit murder in the 2001 killing of Rob Andrew, a 39-year-old advertising executive.

Andrew was fatally shot in the garage of the Oklahoma City home he had previously shared with his wife while he was picking up their two young children before Thanksgiving.

Pavatt attended the same church as the Andrew family and was having an affair with Andrew’s wife, Brenda Andrew. The pair were tried separately and each received a death sentence.

Several weeks before the shooting, Rob Andrew told police that someone was trying to kill him after the brake lines on his car had been cut.

After her husband was killed, Brenda Andrew told police that masked intruders had shot her in the arm and fatally wounded him.

Pavatt and Brenda Andrew fled to Mexico with her two children after the shooting. They were arrested three months later while reentering the United States.

During a clemency hearing last month, Pavatt said he was “not guilty of shooting anyone.” He said he had fallen in love with Brenda Andrew and believed “everything she told me.”

“It was not until my trial that I began to see the extent to which I had been manipulated by Brenda,” Pavatt told the board. “I can see why the jury believed that we were both involved in Rob’s murder.”

Prosecutors have maintained that Pavatt and Andrew conspired to kill Rob Andrew and that, regardless of who fired the shots, both were equally responsible for the murder.

Protesters set fires, damaged storefronts and launched fireworks at riot police in parts of Spain on Wednesday as a nationwide strike over soaring housing costs disrupted transportation, businesses and major roads.

Violence broke out in Barcelona after a largely peaceful march. Some demonstrators vandalized shops along the city’s popular Paseo de Gracia shopping boulevard, ignited small fires and fired fireworks at officers who arrived in riot gear and armored vehicles, according to The Associated Press.

The unrest followed Spain’s first general strike in 14 years. Workers are demanding action on rapidly rising rents and relief from the broader cost-of-living crisis.

A protester holds a sign as objects burn in the background during a demonstration over the housing crisis Wednesday in Barcelona, Spain. (David Ramos/Getty Images)

Housing activists said 400,000 people marched through Barcelona, while city officials put the crowd at 55,000. In Madrid, government officials reported that 120,000 people demonstrated despite heavy rain, the AP reported.

The strike halted or reduced public transportation, closed some businesses and blocked key highways. Police made arrests in several cities, and officers used pepper spray against protesters in Madrid, according to the AP.

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Protesters burn trash cans Wednesday in Barcelona during a nationwide general strike over Spain’s housing crisis. Workers are also seeking greater purchasing power ahead of a snap general election later this month, near Catalunya Square. (Josep Lago/AFP via Getty Images)

The unrest reflects mounting anger over Spain’s housing crisis. That frustration intensified after an 87-year-old Madrid woman who had lived in her apartment for 70 years was evicted after reportedly facing a rent increase that tripled her payments. She died weeks later, according to the BBC.

Housing has emerged as a central political issue before Spain’s Nov. 29 parliamentary elections. Socialist Prime Minister Pedro Sánchez has reportedly urged workers to exercise their right to strike.

Protesters light fires and throw objects during Wednesday’s unrest over the housing crisis in Barcelona, Spain. (David Ramos/Getty Images)

The demonstrations have also triggered a political confrontation. Conservative opposition leaders accused Sánchez’s government of using the unrest to improve its position ahead of the election, according to the BBC.

Spain’s largest labor unions, meanwhile, called the strike a success, while business groups challenged claims that participation was widespread.