Dangers include injecting too much drug, so that an erection can last dangerously long and kill penile tissue, or developing uncomfortable scars, he added.

In a news release, Upjohn said the drug's side effects included mild-to-moderate pain at the site of injection, scarring of penile tissue and an abnormally prolonged erection.

It is defined as the tumescence that will raise 100 grams of penile tissue through one millimetre.

Papaverine, when injected in penile tissue causes direct smooth muscle relaxation and consequent filling of the corpus cavernosum with blood resulting in erection.

However, once healed, the apadravya is usually very pleasurable to wear, as it stimulates the penile tissues internally.

Another image presents the subject lying back with one arm covering the face while someone else's hand pulls on the penile tissue.

Viagra works by blocking an enzyme that normally inhibits blood flow, causing penile tissue to swell.

Depending on the health of the penile tissue, Viagra may or may not result in an erection sufficient for penetration.

Instead, Suporn constructs the vaginal canal with scrotal skin and uses the penile tissues for a labia, clitoris, and other external features.