Mugshots showing the dramatic deterioration in the appearance of drug addicts over years of abuse, are being used in a Met anti-drugs campaign.
Before and after: Pictures show how an addict's face deteriorated
One addict is shown changing from an ordinary 29-year-old woman into little more than a skeleton.
The Met hopes the shock tactic will deter drug dealers and dissuade others from trying crack, cocaine and heroin.
The images will appear on beer mats, nightclub flyers and posters across 16 London boroughs over three weeks.
All three women featured in the campaign are American.
The first, Roseanne Holland, was taken in by police at 29.
Pictures taken of her in custody for drugs-related offences over the following eight years show her cheeks becoming sunken and her face growing gaunt.
Another, Melissa Collara, a pretty 18-year-old was arrested 17 times over three years trying to feed a crack addiction through prostitution.
By 21, her mugshot showed a face aged by crack.
Police believe both these women may be dead.
Penny Wood, the third, is undergoing a drugs rehabilitation programme and gave permission for the photographs to be used in the campaign.
In a letter to the Met, she said: "Not only the outer disfiguration is extreme, the effect it has on your insides is worse."
The pictures of three American woman were provided by US police.
Met Assistant Commissioner Tarique Ghaffur said: "The use of illegal drugs across London devastates communities and the Met is not prepared to tolerate this."
The campaign will run over three weeks in Brent, Camden, Croydon, Hackney, Hammersmith and Fulham, Haringey, Islington, Kensington and Chelsea, Lambeth, Lewisham, Newham, Southwark, Tower Hamlets, Waltham Forest, Wandsworth and Westminster.