The CIA Turned a San Francisco Brothel Into a Lab. What Happened Inside Is the Stuff of Nightmares.

In the late 1950s and early 1960s, a man who followed a prostitute into the apartment at 225 Chestnut Street in San Francisco’s Telegraph Hill neighborhood received a longer, more intimate encounter than he had paid for. Instead of the cramped, charmless quarters he may have expected, he found himself in a carefully decorated bedroom, where colorful prints of French can-can dancers lined the walls, and the windows and lamps were thoughtfully draped with red muslin. Instead of a hurried liaison, he would enjoy candles, cocktails, and plenty of conversation.

The john had unwittingly become a subject in a CIA experiment focused on how drugs and sex might be used to obtain secrets from foreign adversaries. Part of MKUltra, the agency’s broader and highly controversial mind-control research program, Operation Midnight Climax began in 1954. The experiments involved luring men into a heavily surveilled bordello, dosing them with LSD, and filming their reactions to probing questions and subliminal messaging. But it wasn’t long before the research devolved into revelry. By the time the program was cancelled in 1963, the project had become headquarters for, what one writer called, “CIA carnal operations,” where agents regularly took part in voyeurism, drugs, and sex.

While Operation Midnight Climax yielded little insight into mind control, it did provide plenty of grist for conspiracy theorist and antigovernment crusaders alike—as well as a new drug of choice for an emerging counterculture movement.

In the early 1950s, leadership at the nation’s intelligence agencies became obsessed with the idea of mind control. As the Cold War heated up, concerns grew that the Soviets were making successful advances in psychological torture and even brainwashing. According to Stephen Kinzer, author of Poisoner in Chief: Sidney Gottlieb and the CIA Search for Mind Control, two incidents in particular inspired this “mind-control hysteria, particularly at the CIA.”

The first was 1949’s show trial of Hungarian Cardinal József Mindszenty. Back in the United States, CIA officials watched the trial in horror, as a once ardent and outspoken critic of communism falsely confessed to espionage, treason, and conspiring against the Hungarian government in a mechanical and monotone voice. “They thought it was something new,” Kinzer tells Popular Mechanics, “that somebody else was speaking through Mindszenty’s mouth.”

A few years later, when American soldiers returning home from the Korean War began confessing to war crimes and parroting communist propaganda, “the explanation as to why these strapping young men would do such a thing is that their minds had been seized,” Kinzer continues.

To catch up with the Soviets, the CIA launched MKUltra (an arbitrary code name) in the spring of 1953, a top-secret human-experimentation program to figure out how to brainwash and coerce enemy targets. It included more than 100 research projects designed to evaluate a variety of potential mind-control techniques—electroshock therapy, hypnosis, and radiation among them—on both consenting and non-consenting subjects. The vast majority of projects, however, centered on the use of drugs, toxins, and other mind-altering chemicals.

Soon after the program began, its director, a chemist named Sidney Gottlieb, arranged for the CIA to buy the world’s supply of LSD from the Swiss pharmacy where it was discovered and dole it out to the projects taking place under the MKUltra banner, including what would become perhaps its most notorious: Operation Midnight Climax.

The goal of Midnight Climax was to understand what roles, if any, sex and drugs could play in getting a target to reveal sensitive or classified information. To run the operation, Gottlieb hired George Hunter White, a federal narcotics agent, who got to work renovating the apartment on Chestnut Street.

In addition to the sultry decor, the room was fully bugged. Microphones disguised as electrical wall outlets were hooked up to tape recorders, and a large, two-way mirror allowed CIA agents to monitor, film, and photograph the encounters. Behind the mirror, a makeshift control room featured a portable toilet and a refrigerator full of adult beverages.

George Hunter White, supervisor for the New England area of the Federal Narcotics Bureau photographed in December 1952. As part of Operation Midnight Climax, White administered experimental drugs like LSD to American citizens in New York and San Francisco without their consent. His codename was “Morgan Hall.”

Prostitutes were given $100 for each man they lured to the bordello, who were then unknowingly dosed with LSD in the cocktails they were likely pleasantly surprised to receive. With guidance from the agents, the women experimented with different lines of questioning at different points during the evening, working to determine when the men might be most susceptible to mind control. Eventually, these efforts revealed that a man became increasingly talkative if the prostitute asked him to stay a while—even after the sexual transaction was complete.

“It has a tremendous effect on the guy. It’s a boost to his ego if she’s telling him he was really neat, and she wants to stay for a few more hours,” a CIA staffer later explained. “Most of the time, he gets pretty vulnerable. What the hell’s he going to talk about? Not the sex, so he starts talking about his business. It’s at this time she can lead him gently.”

But Operation Midnight Climax was far from a rigorous scientific pursuit.

“Operation Midnight Climax was not scientific at all,” Kinzer says. “The guys weren’t scientists; they weren’t sex therapists or psychologists. They were sitting on a portable toilet drinking cocktails out of a pitcher.”

In fact, the operation seemed to be driven as much by the depravity of the CIA employees involved as by a national security need, with Gottleib allegedly indulging in the services of prostitutes during his visits to San Francisco, and CIA officers volunteering to test the psychedelic drugs on themselves. Little of operational value emerged from the debauchery.

Because of the program’s top-secret classification, as well as Gottlieb’s efforts to destroy all documentation associated with MKUltra, it’s impossible to know how many innocent people were victimized or harmed during Operation Midnight Climax—or the true extent of the experiment.

In 1963, a member of the CIA Inspector General’s staff learned about the depraved experiments happening on Gottlieb’s watch. After an investigation, the Inspector General instructed the agency to follow ethical research guidelines, which meant it could no longer test drugs or other coercion techniques on non-consenting subjects. MKUltra was canceled the same year.

The American public first learned about MKUltra’s human experiments in 1975, and a Senate hearing two years later revealed that dozens of universities and institutions had taken part in testing drugs and other chemicals on unsuspecting people. The revelations have inspired countless conspiracy theories and urban legends—as well as books, movies, and TV shows—that the CIA continues to conduct top-secret human experiments today, something the agency denies.

“The MKULTRA program ran from 1953 until the lack of productive results and ethical concerns about unwitting testing led to its cessation in 1963,” a CIA spokesperson tells Popular Mechanics by email. “CIA ceased all human experimentation in 1972. CIA is committed to transparency regarding this chapter of its history, including by declassifying information on the programs and making it publicly available on CIA.gov.”

Projects like Operation Midnight Climax may have disbanded by the mid-1960s, but the drugs the CIA imported for them were here to stay. Grateful Dead lyricist Robert Hunter and poet Allen Ginsburg reportedly got their first hits of LSD from MKUltra projects. And Ken Kesey, author of One Flew Over the Cuckoo’s Nest and LSD advocate, first tried the hallucinogen in a California VA hospital while participating in a CIA-run experiment—although he didn’t know it at the time.

Ashley Stimpson is a freelance journalist who writes most often about science, conservation, and the outdoors. Her work has appeared in the Guardian, WIRED, Nat Geo, Atlas Obscura, and elsewhere. She lives in Columbia, Maryland, with her partner, their greyhound, and a very bad cat.