People seeking cosmetic surgery risk poor treatment because lack of proper checks has allowed "cowboy" practices to thrive, says a leading surgeon.
Botox is gaining in popularity
And allowing the industry to regulate itself could be disastrous, Douglas McGeorge, of the British Association of Aesthetic Plastic Surgeons, said.
He said treatments such as Botox, and untested new products, were too freely available.
The government claimed self-regulation would improve the quality of treatment.
Mr McGeorge was speaking ahead of the association's annual conference, and highlighted Botox, which uses tiny injections to reduce facial wrinkling, as an example where lack of regulation could be harmful.
"Basically if you wanted to have Botox administered on a park bench, you could do it, these days.
"To foster a 'wild west' approach is not only an affront to reputable professionals who follow the rules, but ultimately creates an unsafe environment for the public."
Singled out for particular criticism were "Botox vouchers" available on the high street.
"Botox has to be prescribed, so you get your voucher and can take it to a practitioner to get the treatment done.
"However, the treatment is paid for long before any counselling takes place - before a decision can be made as to whether it is appropriate for that person."
Mr McGeorge said the absence of regulation meant that dubious products ended up being marketed directly to consumers via the internet.
Isolagen - withdrawn from the US market in 1999 - was offered to UK customers up to three months ago, making what he described as "nonsensical" claims about its rejuvenating powers.
"The public needs to be realistic about the outcomes they can expect from new cosmetic treatments, at least until solid clinical evidence of their efficacy exists."
The decision to allow the industry to regulate itself was taken earlier this year by the Department of Health, following consultation.
Mr McGeorge said that the only firms who actually needed regulation were "cowboy" practitioners, and these were the least likely to regulate themselves.
A spokesman for the Department of Health said that safety and quality of cosmetic treatments were "top priorities".
"We have every confidence that self-regulation will result in improvements for people choosing these non-surgical cosmetic treatments.
"Our plans for change are driven by the need to ensure that we only regulate in cases where the reduction in risks to safety arising from public regulation clearly outweigh the costs and burdens that regulation brings.
"In this case we feel that we can best protect people who wish to have these treatments by using other tools at our disposal."