Inside San Francisco's hottest peptide club

The AGI House, in San Francisco's hilly Twin Peaks neighborhood, is a mansion with an expansive view of the Golden Gate Bridge and the hills of Marin, seven bedrooms, and a toilet on the main floor so modern that it includes written instructions on how to operate. It houses technologists working to accelerate artificial general intelligence, and hosts events that bring together people working toward this mission. But on April 12, the house was reserved for another potentially world-altering development: peptides.

More than 100 people arrived for the California Peptide Club, an invite-only gathering to discuss the substances that have become synonymous with self-optimization. Attendees included several clinicians who prescribe peptides, a peptide manufacturer, the founder of a longevity DAO, a Stanford researcher, and dozens of people who identified as "peptide curious," searching for either the resources or confidence to build their own "stacks." Another 300 had been waitlisted. "Creating the allure of getting invited to the house is actually one of the priorities," says Julius Ritter, the event's organizer and the president of the AGI House.

Interest around peptides has been surging. In April, Google searches for the word "peptide" overtook "pickleball." Joe Rogan takes peptides; so does Jennifer Aniston. The phrase "Chinese peptide dealer" has become a meme, creating a sense of superiority among those who are pepped-up. For those who are not, it can feel like being locked out of the world's greatest party, where everyone is getting hotter, smarter, and better.

Ritter, 24, started the California Peptide Club to widen this circle. His peptide journey began several years ago, when blood tests revealed that his testosterone levels were "in the bottom one percent of men my age," he says. Medication helped somewhat, but not completely. Then he learned about peptides and decided to experiment with CJC-1295 and Ipamorelin, a combination used to stimulate growth hormone production. "I was the only one in my friend group doing it," he says. "My roommates made fun of me. They were like, 'Julius, join the guys in the Tenderloin, injecting yourself in the butt.'"

His results were underwhelming, but a different stack — BPC-157, SS31, Ipamorelin, Tesamorelin, and IGF-1 LR3 — made him feel great. Still, information about peptides was scattered; anyone starting a protocol had to be comfortable with a fair amount of risk and self-experimentation without complete data. A community of people could make it easier to compare notes.

On Sunday, Ritter welcomed people into the AGI House to do just that. This being San Francisco, guests were asked to leave their shoes in a pile at the door. At the entrance stood a pair of black mannequins, which Ritter had adorned with togas — to create a Greco-Roman aesthetic — and had stuffed their outstretched hands with insulin syringes.

Many attendees I spoke to seemed curious but cautious about taking peptides. One woman told me she was too scared to inject GHK-Cu, a copper peptide known for its beauty benefits, but she had started using a topical version in her moisturizer. (Her skin was, indeed, luminous.) Another woman told me she wanted to see more research on popular peptides before trying them, but had already started giving herself injections of NAD+, a coenzyme associated with improved energy and anti-aging. "It's actually kind of fun," she said of stabbing herself with the tiny needle.

The event began with Ritter disappointing everyone by announcing that this was not an injection party. Then he asked how many people had taken peptides. Half the room, or about 50 people, raised their hands. And how many people had injected themselves with a research-only peptide, one labeled "not for human consumption"? Every hand stayed up.

While some peptides, such as insulin or GLP-1s like Ozempic, are legal and can be obtained with a doctor's prescription, most fall into a regulatory gray zone and can be sold only as "research" chemicals. These vials of powder usually come from compounding pharmacies, or research labs in China. This could change in the coming months. On Wednesday, three days after the peptide event, Robert F. Kennedy Jr., the Secretary of Health and Human Services, announced that he would reclassify a dozen peptides that were previously banned, including BPC-157 for recovery, Semax for cognitive enhancement, and, for some reason Melanotan II, a peptide that helps people tan. But for now, the semi-illicit nature of peptides can make using them feel like a science experiment, or actually just doing drugs. How do you reconstitute the vial of powder? Where do you buy insulin needles? If you're not working with a doctor, how do you find the right protocol?

Sunday's event was intended to answer some of those questions with a series of presentations by experts, or at least people who had been messing around with these substances for a few years. There were testimonials of lives improved in all kinds of ways: A functional medicine practitioner named Awais Spall said peptides had spared him from taking opioids to treat muscle pain. Alex Ellis, a former frozen yogurt store owner who now runs an event called BioHack Miami, swore by a cognitive-enhancing peptide called Semax: "an absolute game-changer." Grace Liu, who prescribes peptide stacks to athletes and business leaders, shared the protocols she had designed for several clients, and suggested certain peptides, like Selank (for improving mood) and Epitalon (for better sleep), could be used by just about anyone.

It was difficult to tell where anecdotal evidence ended and medically-backed data began — in part because there isn't much. It was also difficult to tell who was a doctor and who was simply comfortable creating peptide protocols. This seemed to be a broader problem, as one attendee told me: He had sought the advice of a doctor in creating his own peptide stack, and later learned that the doctor was actually an ophthalmologist.

Between talks, Ritter invited everyone to compete in a Kahoot quiz about peptides for a chance to win a peptide mini fridge, along with reconstitution syringes, injection syringes, and alcohol prep pads — a complete starter kit, peptides sold separately. (The winner worked in peptide manufacturing and didn't want it, so the prize went to the runner-up, a founder of a prop tech startup.) Later, Ritter asked for a volunteer to demonstrate how to self-inject Retatrutide, a weight loss drug that's become popular in tech circles. A French woman jumped onstage and offered a tutorial on reconstituting the powder with bacteriostatic water, loading an insulin syringe with the desired dose, and then injecting it into her flesh. Dozens of people raised their phones to film it.

Ritter, who plans on hosting the California Peptide Club monthly, told me that he is "trying to figure out the legality" around offering injections at future gatherings. There might be a table with, say, vials of BPC-157 for people to sample. "People actually like the syringe, because it feels like you're hacking yourself," he said. "And if you've done it once, you're like, wow, this is actually really cool."

Still, he worried about reputational damage if anything went wrong. Last summer, at a Las Vegas event called Revolution Against Aging and Death Festival, two women who received peptide injections at a booth were later hospitalized in critical condition, requiring the use of ventilators. Even when injected correctly, peptides can cause side-effects like nausea or skin irritation in the short term, and a few have been linked with cancer risks in the long term. Peptides of unknown provenance can cause even bigger problems: If you're ordering a vial from a research lab in China, it's hard to be certain of its purity, its concentration, or its impact on your body.

Indeed, risks were not a main topic of conversation at the California Peptide Club — an oversight Ritter brought up to me in the days following the event. "I think we did many things well, but what we didn't do, we didn't take a step back from the accelerationist mindset. Like, hey, what are some of the risks? What do you have to be careful about?"

Risks weren't among the takeaways of the attendees I spoke to. Before I left the event, I chatted with an early-stage venture capitalist, who was enthused by the prospect of starting his own protocol. He had torn his ACL and the recovery was grueling; now, he thought he should've just injected BPC-157. It seemed so obvious, he told me. Next time, he wouldn't be so cautious.

Arielle Pardes is a reporter in San Francisco covering the business and culture of technology.