Experts in New Zealand have cautioned men against ingesting a kind of lichen being touted as “natural Viagra” and an alternative remedy for erectile dysfunction (ED). 

Lichens are a symbiosis between a minimum of two contrasting organisms. This partnership commonly employs a fungus, which acts as a “home” for “tenants” that can perform photosynthesis, such as a green alga and/or a cyanobacterium. As payment for their home, they provide the fungus with nutrients.

Lichens can grow on a myriad of surfaces, including rocks, tree trunks, leather, shells of living animals and even plastic. Ancient Egyptians packed dried lichen into body cavities during mummification of the dead.

While there is an estimated 20,000 different species of lichen, the one in question is known as

Xanthoparmelia scabrosa, but has been dubbed “sexy pavement lichen” due to the characteristics it shares with ED drugs, according to the New Zealand-based news outlet Newsroom.

X. scabrosa grows naturally on roads and pavements and is plentiful in New Zealand. It holds a compound akin to the active ingredient in Viagra and other ED drugs, which partly comprises a class of drugs known as PDE5 inhibitors.

Fortunately, there is not word yet of people actually eating the lichen off pavements in an effort to treat ED. On the other hand, a powdered form of ground X. scabrosa is being retailed as an ED remedy. It can be found, for example, on the Chinese e-commerce site Alibaba where there are hundreds of varieties available for procurement, according to Newsweek.

It should be noted, however, that ingesting any form of X. scabrosa could be dangerous. Chemicals from the lichen could be toxic, Allison Knight, a lichenologist at the University of Otago in New Zealand, told the Newsroom.

lichen-3791187_1280 There are thought to be more than 36 thousand species of lichen in North America. Photo: Pixabay

"I always say in my talks that I don't recommend going out and licking the footpath," Knight said.

Additionally, you may even run the risk of purchasing powder that does not contain natural lichen. One X. scabrosa product was tested and found to contain 80 percent Viagra and 20 percent grass clippings.

Knight did indicate that cultivating big volumes of this lichen species for use in alternative treatment products would not be easy.

“Most lichens grow very slowly, just a few [millimeters] per year, so it would be scarcely sustainable to harvest them," Knight said.