Glen Sycamore is a dating coach who specializes in helping his clientele find love. On his website, you’ll find Tinder tips, or an article on “finding a foreign girlfriend” or “how to get out of the friend zone and avoid it forever” You may also find his first-person account of how a fungus often found protruding from the corpse of a Tibetan caterpillar made him an “animal in the sack, with increased level of sexual stamina.”

That mushroom, which Sycamore discusses at length on his blog, is called Ophiocordyceps sinensis (C. sinensis).

In nature, the C. sinensis fungus colonizes the larvae of the ghost moth, which lives high in the Tibetan Himalayas. But C. sinensis affects larvae, which is why it’s also called “caterpillar fungus” or yartsa gunbu, which translates to “winter worm, summer grass.”

People commonly call it a mushroom, but it’s technically a fungus. Whatever you may call it, Sycamore calls it “magical.”

The fungus is part of the wider genus of Ophiocordyceps fungi that infect unsuspecting insects, colonize them, and eventually kill them. The most famous example of this is the Cordyceps unilateralis, the infamous fungus that infects ants and literally controls their bodies in puppeteer style before the ants finally die.

But the caterpillar fungus has a different reputation: It has kept bedroom doors locked since 1400.

“After it kicks in, my focus goes through the roof, and my energy feels illimitable. Physically, I feel more powerful and virile,” Sycamore tells Inverse. “Cordyceps gets me motivated to meet women even more than I already am.”

It’s not just about a hard-on

As early as the 15th century, Nyamnyi Dorje, a Tibetan physician, described both the medicinal and sexual enhancement qualities of C. sinensis. He claimed that it “increases semen,” and is “a faultless treasure of an ocean of good qualities.”

Caterpillar fungus, which has been lauded for energy and sexual enhancement effects 

Sycamore, the dating coach, can relate. Though his “libido is sky-high” after taking Cordyceps, he calls it “more than just a male enhancement supplement.” Experts who study it agree that Cordyceps is far more than “Himalayan Viagra,” as CNN memorably described it in a 2012 story.

“It’s not just about a hard-on,” says Daniel Winkler, a Cordyceps expert who runs tours in Tibet and has published several papers on the economics and mycology of Cordyceps. “If you’re Chinese, that’s how you buy youth if you’re old.”

Each year, Tibetan collectors sell pounds of real caterpillar fungus to Chinese buyers who are willing to pay up to $35,000 for a single pound (by Winkler’s estimate) to restore their “life energy.” Because of that reputation, scientists and DIY cultivators tried countless times to recreate these rare mushrooms, which are only found above the tree line in the Himalayas.

Sycamore, though, wasn’t even taking real caterpillar fungus. He was taking a related species that’s sold under the same name in the West — though that doesn’t seem to have dampened his enthusiasm for it. But in China, where the price tag reaches into the thousands for the real caterpillar fungus, scientists have been closing in on trying to recreate the real thing, caterpillar and all, for the more discerning buyer.

Now, they’re closer than ever, which for better or worse, has the potential to reshape libidos, economies, and the ecology of a rare medicinal treasure.