When a 33-year-old man first arrived at Dublin’s Adelaide and Meath Hospital with severe back pain, his case seemed typical. But after doctors discovered a mysterious lesion on his right arm, the patient disclosed a key detail: he’d been treating his pain for the past 18 months by injecting himself with his own semen.

The resulting case report in the January issue of the Irish Medical Journal, titled “Semenly” Harmless Back Pain: An Unusual Presentation of a Subcutaneous Abscess, described what is reportedly the first-ever case of semen injection as a medical treatment.

The doctors involved in the report write that the patient first arrived at the hospital complaining of “severe, sudden onset lower back pain,” reportedly caused by lifting a heavy steel object three days earlier.

But when doctors gave him a standard physical exam, they found the unusual-looking lesion on his skin. At that point, the report notes, “the patient disclosed that he had intravenously injected his own semen as an innovative method to treat back pain,” a “cure” that he’d devised “independent of medical advice.”

When doctors asked for more details, the patient added that he had been giving himself a “dose” of semen intramuscularly and intravenously, with a hypodermic needle he bought online, once a month for the past 18 months—but that because of the increased back pain caused by his injury, he had recently given himself three doses.

Unsurprisingly, there is no medical evidence to suggest that semen can cure back pain. But that’s not the only reason it was a bad idea. In the 24 hours that followed, the small lesion swelled to a hard red bulge that covered the majority of his inner forearm. The doctors took an x-ray, and quickly realized that he had given himself subcutaneous emphysema—in other words, a bubble of air had become trapped under his skin.

The corresponding author of the report declined The Daily Beast’s request for comment. But Selim Suner, a professor of emergency medicine at Brown University who was not affiliated with the report, said that there’s two possible explanations for that air bubble. First, there could have been air in the man’s needle that was pushed under the skin when he injected the semen. But it’s also possible, Suner told The Daily Beast, that he had contracted a type of bacteria—commonly known as “flesh eating” bacteria—that produces air while it continues to infect the body.

That’s not all. The report notes that the patient also contracted cellulitis—a skin infection—and an oedema, a buildup of watery fluid in the tissues that occurs when the body is trying to fight off said infection. Upon realizing this, the report notes, doctors immediately provided IV antimicrobial treatment.  

Suner noted that these complications likely didn’t have anything to do with the semen itself—it’s more likely, he said, that the bacteria came from contamination of the skin or the needle from the outside environment.

“The semen doesn’t have anything that would make this case unusual,” he said. “Other than the fact that it’s semen.”

These complications are relatively common in intravenous drug addicts, Suner added. But he acknowledged that this case presented a strange twist.

“I’ve seen and heard of people injecting multiple different things subcutaneously and intravenously,” he said, “but never semen.”

Emphysema, cellulitis, and oedema all sound unpleasant—but Suner said that if those are the only consequences the patient faces, he should consider himself lucky. Bacteria that’s injected intravenously can move throughout the body, he explained, taking root in organs and tissues and causing remote infections. One of the most common examples of this, he said, is endocarditis—an infection of the inner lining of the heart chamber or heart valves that can lead to heart failure.

Another common infection site are the discs between the vertebrae in the back—which, ironically, could cause quite a bit more back pain.

The patient, for his part, didn’t appear to be particularly troubled by the giant red bump on his arm. After his back pain improved, the report notes, he discharged himself without allowing doctors to drain the abscess.   

That was a bad idea. “He will return, or he’s gonna go to another doctor,” Suner predicted, noting that he’d be especially concerned about the possibility that there’s still “flesh eating” bacteria burrowing into the man’s arm. And while he noted that some abscesses drain on their own, he added that “Looking at the abscess, looking at this picture, this is very painful. And I don’t think he’s gonna tolerate waiting for this to drain on its own.”  

Fortunately, this appears to be an isolated incident. The doctors write in the report that they scanned biomedical databases, Google, and “more eclectic internet sites and forums” for reports of other “medical” semen injections, and came up empty.

But that doesn’t mean there aren’t applicable lessons. Like Suner, the report cautions against the “dangers of venipuncture when carried out by the untrained layperson” and “the vascular and soft tissue hazards surrounding the attempted injection of substances not intended for intravenous use.” In other words, don’t try this at home—and definitely don’t try it with semen.