Burn surgeons in Melbourne are warning about the dangerous of "cupping" after eight men had to have skin grafts when they were burned during the process.

Burn specialists at a Melbourne hospital have warned people about the dangers of "cupping" after eight men needed skin grafts thanks to the alternative therapy.

Cupping involves placing a glass or plastic cup, sometimes heated with the aid of an accelerant to create suction, on the skin.

The therapy is commonly used for pain relief and to treat colds.

The seven year study examined more than 18,700 patients enrolled in the Burns Registry of Australia and New Zealand.

The Alfred Hospital burns specialist and plastic surgeon Marc Seifman led research into cupping and told practitioners to warn their clients about the risks.

"While there were only a small number of cupping related severe burns injuries recorded, we believe there are likely many more instances of less severe injuries," Mr Seifman said in a statement on Monday.

Twenty cupping clients needed to be hospitalised, suffering burns to their face, hands, upper body and eight of those were men who needed skin grafts.

Mr Seifman said most cupping burn injuries were accidental and happened at home.