Social media posts by cosmetic surgeons can be harmful to patients.

The Australian Society of Plastic Surgeons believes greed-driven surgeons are damaging the industry's reputation by looking at a patient as a commodity to be exploited.

Some surgeons are self-promoting through social media - offering free procedures for advertisements on Instagram.

New Zealand Institute of Plastic and Cosmetic Surgery co-director, Jonathan Wheeler, told Mike Hosking just getting rid of wrinkles could be positive.

But he says harm can occur when unrealistic expectations are put out there from posts which suggest an outcome that isn't possible for most people.

Wheeler says social media can be good for getting information out, but there is a line.