You won’t find any mention of Dr. Dmitri Isaev’s clinic online. Patients can’t look up its number in a phone book. Both its address and name are kept secret and those who would like to see Isaev, Russia’s top sexology expert, find out about the location of his St. Petersburg clinic only by word of mouth.

For nine years, Isaev, a 60-year-old psychiatrist, led a five-member commission of doctors at St. Petersburg State Pediatric Medical University which issued official permission for gender-reassignment surgeries and for the necessary changes to identity documents.

It ranked as both the country’s largest such commission and among its most active, authorizing corrective procedures for up to half of the few hundred sex-change surgeries that occur in Russia each year, according to Isaev. Costs for the permits were kept at a relatively modest 10,000-15,000 rubles, or about $162-$243, based on current exchange rates.

But on July 20, 2015, Isaev, a well respected academic, was forced to resign and his commission was dissolved, pushing Russia’s trans community even further to the periphery of society.

So, he moved on and created another commission. This time, under cover.

It took 11 months for Isaev to find a location in St. Petersburg, traditionally considered Russia’s most liberal city, that would allow such a commission to operate under its auspices. A first try employed Isaev, but declined the commission.

Pressure from groups describing themselves as defenders of Russia’s majority Orthodox Christian faith explains that reluctance. Such activists use public shaming campaigns to target supporters or suspected members of Russia’s LGBTQ community. They had hailed the closure of Isaev’s first commission, and would not likely tolerate the opening of a second. They do not appear aware that such a body now exists.

Their campaign against Isaev started in 2014, a year after the passage of a federal law banning perceived “gay propaganda.” A self-styled gay “hunter” named Timur Bulatov (whose legal last name is coincidentally also Isaev) spearheaded the initiative. When interviewed by Coda about Isaev’s work, Bulatov charged that the doctor had “created an entire army of gender perverts.”

The campaign against Isaev mounted for months before the psychiatrist was forced to leave his faculty post in July 2015. First came texts to his cell phone with messages like “You’re a pervert,” he recounted. Then, phone calls from strangers threatening to have him fired as the faculty head of clinical psychology. A full-fledged social media campaign followed, distributing his phone number and photo across anti-gay social-media pages.

Finally, as complaints about his work with transgender Russians mounted at the district attorney’s office, the State Pediatric Medical University’s rector told him to resign and to leave quietly, Isaev said.

“As long as it was in electronic form, the university said nothing,” Isaev said of the complaints. “I didn’t expect the university administration would take their side.”

Even when Isaev resigned and moved into private practice, he said that Bulatov began hounding the administration of the first clinic that employed him, threatening to “spread information that this is not a clinic for normal Russians, for normal Orthodox people.”

Asked about his treatment of Isaev, Bulatov compared him to Dr. Frankenstein.

In interviews with Russian media outlets, the university’s rector Vladimir Levanovich said that the university had ignored the complaints made against the doctor and that Isaev had freely resigned in order to focus on his research.

Often appointed by the government, university officials are careful to avoid public scrutiny, Isaev said. “Everything is ordered vertically . . . The fewer problems, the more calmly they live. So they decided to get rid of the source of their problems.”

The past few years remind the doctor of the mid-1980s, when he first started studying male teenagers’ sexual behavior. Frustrated by the lack of recent research (the latest citations in Soviet academic papers dated to the 1920s), Isaev requested articles on homosexuality from outside the Soviet Union. Soviet customs officials, though, declined the requests, saying that “Pornography is not allowed in the USSR.”

But at least in those days, “the rules of the game were clear,” Isaev added. “It’s incredibly complicated to predict what can happen now.”

After perestroika and the 1991 collapse of the Soviet Union, Isaev openly pursued his research, regularly traveling to international conferences. He has since published over 120 academic works on homosexuality, transgenderism and other psycho-sexual topics.

Those publications and his work on the former State Pediatric Medical University commission made him nationally known among Russia’s transgender community. The loss of his commission and faculty position came as a blow to trans Russians, who have a shrinking list of advocates.

“Things moved from a dead stop thanks to Isaev,” said Anastasia Gerasimova, a 40-something, Moscow-based epilation specialist who received permission for a sex-change from Isaev’s first commission. “People would come to his consultations from across the country.”

As of November, Isaev’s new commission had seen 38 patients over the past seven months.

One local transgender activist, Igor Burtsyev, half-joked that some activists in the city are partially pleased that the old commission closed since it gives the new body greater independence from an official government institution like the University.

“Part of us want the government to actually change something, but those of us quite close to the situation understand that until the government changes things, we actually have it much better,” Burtsyev explained.

Isaev also sees the paradox in the temporary relief provided by the move to a private setting. But with the Russian government largely endorsing the crusade against homosexuality, he predicts that leaving Russia may soon be the only way he can continue his research.

“Sexuality is a model that undermines the foundation of authoritarianism,” he commented. “A battle against sexuality is always a battle against individuality and, by definition, against liberal values.”