Penis enlargement operations have seen a popularity boom in recent years - but when things go wrong the consequences can be gruesome.
A first-of-its kind scientific study has examined the horrifying effects of 11 men's penis enlargement failures.
Gangrene, deformity, 'severe shortening', infection and massive swelling were all stomach-churning results of the risky procedure.
The study, which explains the cases in gory detail, warns having injections to boost the manhood can result in 'devastating and long-lasting complications'.
Researchers at the University of California in Irvine followed the cases of 11 men who had complications after penis enlargement surgery, also known as penoplasty.
The procedure is carried out by injecting a substance into the penis tissue to make the organ thicker for aesthetic or sexual reasons.
Men in the study had an average age of 47, with the youngest just 21 and the eldest 77 years old.
Most of the patients had silicone injections, though one injected himself with saline, and two others had injections of fat or a soft tissue replacing substance.
Four of the patients – including the youngest men in the study, at the ages of 21 and 36 – made the enlargement attempts themselves.
But these ambitious DIYers were rewarded with deformity, infection, gangrene, chronic ulceration and a 'buried penis'.
Many of the afflicted men required surgery – in some cases the flesh of the penis had to be completely stripped away or split open.
The authors wrote in their study: 'Penile enlargement surgeries are often promoted and presented as safe with minimal risks, yet we have seen... the risks are significant.'
In one particularly disturbing case, a 48-year-old man had fat injected under the skin on his penis, but suffered 'major penile shaft swelling and deformity'.
The hugely swollen penis, which resembled a potato, had to be sliced just below the head and the skin peeled back to the body like a banana so the fat could be removed.
The skin was then rolled back down and reattached near the head of the penis, and the patient then had to be treated for an infection after surgery.
Researchers were particularly concerned the vast majority of men seeking penis enlargement surgery have normal members to begin with.
They suggest fear about having a small penis is a form of body dysmorphia, in which people become obsessive about finding faults with their body.
'Most patients who seek penile augmentation have normal penile length and anatomy,' they wrote in the Journal of Sexual Medicine.
At one unnamed clinic, over a two-year period every single man who enquired about the procedure had a normal penis, the report said.
And its authors added: 'Most men seeking penile lengthening surgery overestimate normal penile length. In some cases, patients may benefit from psychotherapy.
'Instead of risking the potentially detrimental complications of penile enhancement surgery, men with normal penile size and anatomy may experience benefit from less risky alternatives.'
But they said men who are determined to have the procedure should be required to discuss their reasons and expectations with a professional beforehand.
In a final warning the authors added there was a 'very real potential for devastating and long-lasting complications'.