A resurfaced autopsy case report is renewing scrutiny of synthol, the oil-based injectable some bodybuilders use to create the illusion of muscle size without lifting a single additional pound.
Brazilian bodybuilder Valdir Segato, who became known as the “Brazilian Hulk” after injecting Synthol into his muscles to build enormous biceps, pectorals and back muscles, passed away on his 55th birthday in 2022.
Synthol is typically a mixture of oil, alcohol, and lidocaine injected directly into muscle tissue to inflate its appearance. Unlike ste**ids, which work with the body’s hormonal systems to build genuine tissue, synthol offers no functional benefit.
The body has no way to metabolize the oil once it’s inside the muscle, so it simply sits there. Over time, the immune system responds by walling off the oil deposits with clusters of immune cells, forming what are known as granulomas. On imaging scans, muscle affected this way loses its normal, dense structure and instead resembles a sponge riddled with holes.
The condition has a clinical name: sclerosing lipogranulomatosis, a progressive process that continues spreading even after the initial contaminant has been sealed off. Rather than making muscle stronger, the oil physically pushes muscle fibers apart, replaces contractile tissue with scarring, and can raise pressure inside the fascia to the point where blood flow is cut off entirely, causing tissue to di3 while still attached to a living body.
Documented fatalities tied to synthol remain rare in medical literature, largely because much of its use happens outside settings where it gets studied. But Valdir’s case stood out.
The man had stopped using injectable oil a full eight years before his passing, yet the oil was still identified as the underlying cause. Investigators found that the retained oil and surrounding granulomas had been abnormally producing activated vitamin D, which drove his blood calcium to dangerous levels. That excess calcium eventually deposited in his organs, including his heart, leading to calcification and cardiac arrest.
Synthol’s effects don’t necessarily end when injections stop. Doctors examining unrelated symptoms may have no reason to suspect oil injections from years earlier, since patients often don’t disclose past use and the resulting conditions rarely present with an obvious link.
Medical experts stress that anyone with a history of synthol use, however distant, should inform their doctor, since early recognition may be the only real defense against outcomes like this one.
