You might have learned about it from a Liz Phair song or seen it depicted on the FX series Nip/Tuck. Maybe you learned about it from an episode of HBO’s Real Sex or perhaps you are one of the hundreds of gullible people who continue to ask about it every year on Yahoo! Answers. If you’re a young heterosexual woman, you may have heard it from a man in high school or college and if you’re a young heterosexual man, you may have said this to a woman during those same years of your life—and hopefully not after.

I’m talking, of course, about the myth that semen is good for the skin.

In her song “H.W.C.”—I’ll leave you to Google what that stands for—Liz Phair brags that her “skin’s getting clear” from her active sex life. And in one particularly memorable subplot of Nip/Tuck, the show’s female characters market a face cream made from male ejaculate to Joan Rivers. Starting in the mid aughts, a new celebrity or viral sensation has perpetuated the practice of a “semen facial” almost every year: the late Cosmo editor Helen Gurney Brown, Melrose Place star Heather Locklear, a 67-year-old grandmother, the list goes on.

Cosmo was still weighing the pros and cons of the “semen facial” as recently as last March. Much like semen itself, this is a myth that seems to exist in endless supply.

I asked Dr. Will Kirby, a Beverly Hills dermatologist, to help me finally put it to bed once and for all. According to Dr. Kirby, not only is there no proof that semen has any dermatological benefits, applying semen to your face could prove to be dangerous.

Dr. Kirby has more personal experience refuting the myth than you might expect. In our interview, he notes that “this is an area of discussion that gets brought to my attention by patients in my dermatology practice with relative frequency.” Apparently, it’s not just teenagers who continue to buy into it—grown adults are still asking board-certified dermatologists about semen facials in earnest.

But perhaps they can’t be blamed. The pseudoscience behind the semen facial sounds compelling to the untrained ear. Semen is supposedly “packed with protein” with “zinc, magnesium, calcium, potassium and fructose” in the mix as well. One of the basic amines in semen—spermine—has also been touted as being beneficial for skin because it acts as an antioxidant, which was the rationale behind the spermine facial once offered at a costly New York spa.

Protein, minerals, and antioxidants? To a generation raised on the paleo diet and besieged by pomegranate propaganda, semen sounds like a magical elixir. There’s just one catch: things that are good to eat aren’t necessarily good to slather all over your face, no matter how much pressure you’re currently under to get a kale facial.

“While a healthy, balanced diet contains vitamins and minerals as well as protein, the potential benefits of a similar topical preparation and their relationship to healthy skin remain elusive,” says Kirby.

In short: there is no scientific literature to back up the idea of a semen facial and, no, sex bloggers don’t count.

And before you try to reap the potential benefits of semen by incorporating it into your diet instead, you should know just how much semen you would have to ingest in order to reap them. According to Columbia University’s health promotion website, you would need to be “gulping gallons of it each day” to experience any of the positive effects of semen. Indeed, if you look at the nutritional content of a “single serving” of semen, the only notable nutrient it contains is zinc. And even then, your mileage may vary depending on the source.

“After all,” says Kirby, “the ratios of the ingredients range widely from man to man and even in the same person there can be variance from one emission to the next.”

Dr. Kirby strongly suggests that beauty aficionados worry less about the unproven possibility of glowing, semen-infused skin and more about the potential dangers of applying it to the face.

“Many people—even monogamous couples—have undiagnosed sexually transmitted infections (STIs) that could be spread to the mucous membranes (lips, nostrils and eyes) via topical application of male ejaculate for those seeking aesthetic improvement,” Kirby notes.

Many people who use semen facials either derive their ingredients from a monogamous male partner or claim that their source has been tested for STIs but one can never be too sure.

“So while smooth, soft, supple skin might be beautiful, chlamydia of the eye isn't,” says Kirby.

Beyond the possibility of STIs, some women might also be allergic to semen with symptoms that are anything but beneficial to the skin.

“More worrisome is the fact there have been a number of cases where a woman developed an allergy to one or more of the proteins in semen which result in allergic contact dermatitis (ACD) that is manifested by temporary erythema (redness) and by mild edema (swelling) on the skin areas to which it is applied,” says Kirby.

The condition—known as human seminal plasma protein hypersensitivity—is relatively uncommon but the dangers are real enough to justify avoiding topical application. In rare cases for women with a particularly severe semen allergy, Dr. Kirby notes, exposure to semen could even cause anaphylaxis. If you want to try a semen facial, you should be prepared for the unlikely contingency of an embarrassing trip to the emergency room.

So if this myth has no scientific backing and several proven dangers, where does it even come from?

One easy answer would be that men cite it as a sort of reverse justification for wanting to replicate a remarkably popular practice in pornography: the “money shot.” It’s an explanation that makes sense: many women first hear about the hypothetical dermatological benefits of semen in the context of being asked by a sexual partner to, let’s say, test that hypothesis firsthand. And why might some men be so adamant about trying the money shot at home? For film scholar Linda Williams, the money shot’s popularity can be attributed to the fact that it provides “visual evidence” of male pleasure in the face of the possibility of female pleasure, both literally and figuratively. Simply put: The proof is in the pudding.

But we can also trace the underlying logic behind the “semen facial” to the foundation of Western Civilization itself. In her book Straight: The Surprisingly Short History of Heterosexuality, historian Hanne Blank notes that Aristotle and his contemporaries defined semen as “the essence of life, a distilled form of the pneuma or breath.” In the Aristotelian tradition, women require semen—or “doses of masculine heat,” as Blank summarizes—to invigorate the “cool, dense, and wet female body.” Women needed these fluid gifts from the more “perfected” male form but men, obviously, don’t need vaginal fluid to be perfect.

Over two millennia later, we still have not erased the bullet points of this philosophy. In fact, we’ve shored them up with shoddy science instead.

When a small survey of less than three hundred women concluded that women who had unprotected sex were less depressed than their condom-using counterparts, researchers and the media rushed to attribute the conclusion to the “antidepressant compounds” in semen. The research is nowhere near scientifically sound but its cultural force is unmistakable: We’ve believed for centuries that semen is some sort of fountain of youth and happiness, we’re not about to stop now.

And neither is Tracy Kiss, a beauty blogger and the most recent viral sensation to promote the semen facial. I checked in with Kiss to see if she was still keeping up with her routine and she reports that she still has a facial “once every week or two.” She notes that they still “help with the condition of [her] skin” and still recommends the semen facial as “a very worthwhile and natural procedure that is totally free and with a neverending supply.”

Meanwhile, those seeking proven methods of skin care can stick to solid dermatological advice. For his part, Dr. Kirby recommends “sun avoidance, barrier protection, and a broad spectrum SPF” or a prescription retinoid.

“Moisturizers, Botox, surgery, peels, and lasers fall down the list,” he says, “and at the very, very bottom—right next to voodoo, a lucky rabbit’s foot, and just keeping your fingers crossed—are semen facials.”