In a startling bizarro case of gains-gone-bad, British doctors discovered a young "bodybuilder" who had nearly destroyed his right triceps after he got injured.

Blame a nasty shortcut: coconut oil.

Because his muscle had started atrophying after the injury, he'd started injecting himself with coconut oil—and a combination of other harmful chemicals that caused dangerous side effects, according to a new case study published in The British Medical Journal titled "Muscle mania: the quest for the perfect body."

Earlier this year, the 25-year-old guy showed up to the hospital complaining that his elbow had been hurting and immobile for several months. He said he'd been bodybuilding for four years, and that he went to the gym three times a week. Nothing weird about that, right? But when the doctors started examining him, he was "agitated and sweating profusely" even though they'd ruled out infection, which is basically doctor-speak for "this guy seems kinda shady and there's no real medical explanation for him to act this weird."

After an X-ray and an MRI, the doctors realized that he had totally ruptured his triceps ("rare in young patients," the doctors wrote) and developed cysts within his muscles. Once the radiologist asked a few questions—cysts in the middle of a blown tricep are pretty freaking unusual in otherwise healthy 25-year-old guys—our wannabe He-Man revealed the truth: He'd injected himself with coconut oil (which explained the lesions within his muscles), plus a nasty cocktail of:

– rapid-acting insulin, which he thought would promote growth and decrease body fat. (Instead, it gave him seizures and decayed the bone of his left shoulder joint.)
– liothyronine, a drug normally used to treat under-active thyroid problems, which threw off his normal sex hormones "with long-term implications for fertility," the doctors noted.
– vitamin B12, which caused a previous infection so severe that he had to be admitted to the hospital
– Anabolic steroids, which caused gynaecomastia (aka man-boobs) and a non-cancerous mass in his liver that had to be surgically operated on
– Excessive protein supplements, leading to acute kidney inflammation

If your reaction was, "Dude, wtf?" then allow our good London doctors to explain: "This is a little recognised practice globally with sparse documentation in the medical literature. However, it is well known among Arab and Middle Eastern communities and on internet sites." (Not on this site, guys—if you want big triceps, you'll have to do it the Vin Diesel way.)

Cases like this are rare, but they have popped up before. A team of German doctors had to treat a 40-year-old "semi-pro bodybuilder" for muscle destruction and septic scarring in his right arm because he injected himself with sesame oil every day for eight years. And there's the infamous case of Brazil's Romario Dos Santos Alves, who nearly lost his arms because of hardened synthol, and then injected his man-boob-pecs with it anyway.

“The few cases of natural oil self-inoculation formally reported are likely to be the tip of the iceberg,” the doctors write. “We need to be aware of these cases to enable correct clinical diagnoses, and also to recognize other self-abusive and potentially life-threatening practices.”

The kicker: Even after the doctors surgically repaired the dude's arm and sent him home with a regimen of "gentle" physical therapy, he kept doing the same damn thing: "Despite being counselled about the potential future risks, the patient continues to practice unsafe techniques to achieve his desired body image."

Moral of the story? Don't inject your muscles with oil. Don't inject your body with steroids, thyroid drugs, insulin, or anything else unless you are absolutely prepared to face the potential side effects. And if you injure yourself, make an appointment with a physical therapist or a doctor so you can heal up the right way.

And for all you guys out there with normal, healthy triceps: Here's a roster of the arm workouts on mensfitness.com.