People Are Injecting Stem Cells Into Their Penises

Earlier this year, the bodybuilder turned trainer, health wonk, and self-proclaimed biohacker Ben Greenfield made headlines when he announced that he’d had stem cells—extracted from his body fat—injected directly into his penis to make it bigger. The procedure, he insisted, worked like a charm; within days, he claimed his erections were larger and harder and his orgasms better. He did admit that the orgasms might be a placebo effect and he hadn’t actually measured his ostensible growth. Still, he insisted, stem cells had proven an effective means of male enhancement.

This may have seemed to many like an extreme act by one daring (or crazy) man. But Greenfield was only able to try it because a clinic, US Stem Cell, was willing to do the procedure for him—and may be willing to offer this purported therapy to other men. (I reached out to US Stem Cell to confirm this, but they did not respond to my queries.) It’s difficult to find other clinics that openly offer stem cell treatments expressly for penile enhancement. However, many offer similar procedures to treat erectile dysfunction, and some will frame them as male enhancement procedures as well, says University of Minnesota professor Leigh Turner, who studies stem cell markets. “Some businesses,” he adds, “are quite happy to play both sides of that line.”

Plenty of men seem willing to shell out thousands of dollars for this seemingly painful and bizarre service, too. Turner notes that it’s impossible to calculate exactly how many people seek out any type of stem cell treatment. And none of the stem cell clinics offering penile treatments responded to my requests for information of their client base or number of queries they get about enhancement procedures. However, Ryan Terlecki, a urologist at the Wake Forest Baptist Medical Center, a research hospital known for its (rigorous, serious) stem cell therapy studies, tells me that men ask him about stem cell-based erectile enhancement just about every day.

Stem cells are basically blank slates, able to turn into specialized tissue to renew our heal us as needed. Generally, stem cells from an embryo or fetus can turn into any kind of tissue, while adult stem cells turn into the types of tissue in the organ they reside in. Research into using stem cells—including adult stem cells manipulated to be more versatile—to accelerate healing or treat difficult illnesses has garnered public interest and enthusiasm.

As of today only a few such therapies have been proven effective, chiefly for blood disorders like leukemia. But under US regulation, clinics can legally remove stem cells from an adult and, without manipulating them, re-inject those cells back into their bodies, as this is seen as a harmless practice. (Tightly controlled studies can gain permission to manipulate stem cells before re-injection, but these are rare.) The clinics just can’t claim they can definitively cure anything via such unproven methods.

To be clear, extracting adult fat stem cells and re-injecting them directly into the dick of the individual they were harvested from—whether to treat erectile dysfunction or to provide purported male enhancement—is not one of the few proven stem cell therapies. The clinics offering such procedures are a recent phenomenon to boot. So why are these clinics willing to sell men on an (at best) experimental cock shot? And why are some men seemingly willing to try it, especially when there are so many better-known supplements and procedures on the market offering about the same hope of adding a few inches or extra turgidity to their boners?

Some of the interest in this procedure likely stems from the fact that a few studies have shown that certain types of stem cell therapies may help treat one narrow type of erectile dysfunction linked to limited nerve damage after a prostatectomy. These studies are all in their early stages, working with samples too small to prove anything. But some clinics and men may just assume if stem cells can help with ED, it could do wonders for a healthy penis too. Most of the interest in this, my experts agreed, likely comes down to the fact that stem cells have been hyped by researchers and writers so much, but their potential remains so vague, that they seem to many like a panacea.

Consumers also seem to assume that, even if stem cell therapies are experimental, they aren’t risky, because they just involve shooting up something from your own body. That’s more attractive for some men than taking some pill—even a purportedly natural supplement—for penile enhancement. The folks willing to try stem cells rather than stick to established enhancements, Terlecki says, also seem to have money to blow and to be willing to try everything anyone tells them will make them feel younger and more virile, like dubious testosterone treatments.

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But in a healthy penis, Terlecki explains, non-manipulated stem cells wash into the bloodstream within minutes. Even if they stuck around for some reason, there is no guarantee they would turn into useful tissue. So therapies like the one Greenfield tried is likely doing jack all for johnsons.

Some clinics may still offer stem cell-based ED treatments because they are true believers who think the mainstream scientific community and relevant regulators just don’t understand enough about stem cells to see the good they can do. But others are likely taking advantage of pop enthusiasm and the current regulatory framework. Turner tells me that a fair number of the over 500 clinics that cropped up in the US between 2011 and 2016, offering stem cell treatments for a ton of issues stem cells have not been proven to address—from joint issues to Parkinson’s disease—are run by individuals with track records of exploiting interest in medical fads, and records of civil fraud lawsuits.

Last year, the US Food and Drug Administration vowed to increase its regulation of stem cell clinics. But that will take time to implement, and will likely involve light policing of existing rules, rather than new restrictions on claims and current practices. Consumer advocates, Terlecki adds, lack the resources to police predatory clinics through public education on their own.

This is worrisome as stem cell procedures are not risk free.

In theory, Terlecki says, using a person’s own unmanipulated stem cells for male enhancement is harmless. That may make such procedures safer than things like fat, silicon block, or mineral oil injections, which Terlecki tells me men often seek. Those “remedies” do, however, often lead to deformities, damaged tissue, and painful operations that he has to perform to remove the foreign tissue from their penises.

You can’t always trust that clinics are abiding by existing rules. Last fall, for instance, US Stem Cell, the company Greenfield went to, permanently damaged three patients’ vision when they went in for fat-based stem cell therapies for macular degeneration, likely due to poor practices. The company did not comply well with FDA investigations into their practices. Stem cell procedures gone awry have also led cells to settle in odd places and develop into tumor-like masses. That means that one always stands a small risk of, say, a lump of cartilage blossoming out of the side of their penis after a stem cell-based enhancement procedure.

For Turner, the bigger risks are less physical and more conceptual, though. He is especially worried about growing hype leading those with few resources to blow their savings on snake oil, and about sham procedures lowering overall faith in the wider medical system. All he or any other consumer advocate can really do for now, though, is try to make it clear that there is no known benefit in jabbing a needle of one’s own fat-based stem cells into one’s penis, and hope that minimal harm will befall anyone before the hype dies down.

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