Australia's medicines regulator is warning about an influx from overseas of unregulated male sexual enhancement drugs that can cause serious medical problems.
The Therapeutic Goods Administration has issued two safety alerts in the past week about products bought on the internet and is working with Customs to try to stop further shipments coming into Australia.
Some sexual enhancers are marketed as natural products but contain unlisted ingredients that could be risky for middle-aged men with high blood pressure and heart problems.
Doctors are worried some men may be circumventing advice from their GP and buying inappropriate medicines.
The latest warnings include one product containing undeclared sildenafil - the ingredient in the prescription impotence medication Viagra.
Another is marketed on the internet as a natural male sexual enhancer but has been found to contain yohimbine, a prescription stimulant used for impotence.
A spokeswoman said it was difficult to know how many counterfeit and unapproved drugs were coming into Australia, or their origins, because the physical locations could be easily masked.
The TGA advised consumers to use extreme caution when buying medicines over the internet that were not listed on the Australian Register of Therapeutic Goods.
"Almost any illegal or unapproved medicine can be sourced online, however sexual enhancement medicines are a very common product offered by overseas suppliers," she said.
The regulator urged health professionals to report any serious adverse events linked to the products.
Australian Medical Association WA president Richard Choong said men took a huge gamble buying unregulated products on the internet.
"They end up taking poisons that can harm them," he said.