Health watchdogs issued another warning today after a young woman died after taking illegal tanning injections bought off the internet.
Jenna Vickers, 26, from Bolton, was found slumped in a tanning shop in the town on Monday.
Staff broke down the door of the cubicle she was in but could not save her.
It is not yet known if there is any link between Miss Vickers' death and the tanning injections.
But on August 17, in an entry on Miss Vickers' Twitter page, she indicated she had taken the jabs.
She said: "Getting a lovely tan now . . . And I've had no no side effects :) Very happy Bunny."
Tanning injections of the product Melanotan are banned from sale in the UK but can be bought online.
Melanotan is a synthetic hormone that encourages the body to produce melanin, the body's natural protection from the sun, which also darkens the skin.
But the drug, which has to be injected into the skin, has not been given official approval as safe to use.
The Medicines and Healthcare products Regulatory Agency (MHRA), which regulates medicines and ensures they are safe to use, appealed for anyone who has bought the drug to contact them.
A spokesman said: "We are warning people not to use this product.
"Melanotan is not licensed for use in the UK and there is no information about its safety. Side effects from its use could be extremely serious.
"If you have used this product do not use it again and if you have any health concerns you should seek advice from your doctor.
"The sale of Melanotan is a criminal offence and we advise people who have bought this product to contact us."
Miss Vickers is understood to have been engaged to be married and posted on Twitter that she had, "Never been happier".
A spokesman for Greater Manchester Police (GMP) said: "At about 11.10am on Monday 3 September 2012 police in Bolton were called to a tanning salon on Bury Road following a report of a sudden death.
"Police officers attended and found the body of a 26-year-old woman.
"There are not believed to be any suspicious circumstances surrounding the death and the case has been passed to the coroner."
The MHRA can be contacted on 0203 080 6330 or at firstname.lastname@example.org