Updated

Ars Technica reported on November 12, 2026 that a Massachusetts man's secret use of synthetic testosterone intended for cows nearly destroyed his heart. For 11 years he suffered repeated heart failures, including one that required life support, and saw many specialists without disclosing his drug use, one of which was approved only for animals. Doctors at Massachusetts General Hospital pieced it together in 2026, after his heart failed again following a Caribbean trip, and ruled out infection, autoimmune disease, medication side effects and toxins. Their case report in the New England Journal of Medicine pointed to high doses of testosterone or a related steroid, with his left heart chamber pumping just 20 percent of its blood. Doctors warn that such life-threatening cases are becoming more common, and clinicians should expect more patients with long-term damage such as cardiomyopathy. The authors estimate that 2.9 to 4 million Americans, mostly male athletes, use these drugs, and they call recovery "lengthy and varied." The report gave no further details on the patient's treatment.