An injectable tanning drug dubbed "the Barbie drug" is being used in Canada, despite not being approved by authorities.

The drug is called Melanotan II and is said to cause tanning of the skin by mimicking hormones in the body that darken skin when exposed to ultraviolet light.

Reports have emerged that since using the product, some users have experienced the appearance of new moles on their body.

The product is available to buy online, but has not been approved for human use by Health Canada or by the Food and Drug Administration in the U.S.

The drug, which must be taken regularly, is not recommended by health care professionals or the Canadian Cancer Society.

In an interview with CTV News Channel, the head of dermatology at Toronto Western Hospital Dr. Cheryl Rosen warned against using the drug

"We don't know in the long term what stimulating the pigment cells of your skin, if that will end in just a benign stimulation, whether it will end in these unusual moles that have been reported or it could even end up in a cancer," she said Thursday, noting the lack of research into its effects.

"We just don't know because the studies have not been done."

Users of the drug also claim it also helps to curb hunger and raise sexual appetites, she said.

"There are reports that it increases libido and decreases appetite," said Rosen. "So you can see that some people might find this an interesting combination of results."

Rosen recommends "absolutely" staying away from Melanotan II, and says that if you are interested in having a tanned appearance to stick to spray-on self tanners.

This message was echoed by the Canadian Cancer Society.

On their website the CCS wrote the following of products such as Melanotan II: "Health Canada has not approved the use of any of these products for tanning purposes. Until they have been reviewed and experts believe they are safe, these products should be avoided."