AMSTERDAM — Very few people know Dr. Zee's real name. There's a reason for that. The "godfather of legal highs," as The Guardian newspaper once dubbed him, knows he's made a few enemies over the years. And so the less that's known about him, the better.

Dr. Zee heads a company that has been supplying Europe with "legal highs' — non-banned narcotics — since 2009. Not surprisingly, it took quite a few telephone conversations before we were finally able to meet, in Amsterdam, earlier this year. In his office, somewhere in an industrial complex in the Dutch city, he produces substances that have the same effect as illegal narcotics but are made from legally available chemicals. Some of the chemicals mentioned on a white board in his office are psychoactive and can either shut down or stimulate entire areas of the brain. They make people high, in other words. Users might see colored, breathing circles for half a day, or feel full of love for a few hours.

Dr. Zee has spent the past eight years inventing chemical formulas that he then sends to a laboratory in India. The lab produces samples of the drug in powdered form and sends these back to Dr. Zee, who then tests the drugs on himself — in ever increasing dosages — until he either feels the effect of the drug, or lack thereof. "It only happens once or twice a year that I discover something truly amazing," he says of his efforts.

People have the right to get high.

When that happens, Dr. Zee — just like a normal pharmaceutical company would — sends the drug samples to specialized laboratories for testing on animals. If the substance is shown to be safe for rats, it can then be tested by experienced drug users, so-called "psychonauts." And if it passes the human test, Dr. Zee puts in an order with the lab in India to manufacture anywhere from a few hundred kilograms to a ton of the drug, which he stores in a warehouse facility or inside a safe.

"I am not a drug developer or designer," Dr. Zee explains. "Intoxicating substances already exist. They only have to be discovered. I have commercialized these substances to provide people with an affordable, clean and effective alternative to illegal drugs. I believe that people in any society have the right to get high."

He says the system stigmatizes consumers, while the prohibition of drugs benefits those who break the law. "Our inventions could end up putting the illegal cartels out of business," Dr. Zee adds.

Cat-and-mouse game

The substances are marketed and sold online under names like "bath salts' or "research chemicals." In scientific circles, they're known as "new psychoactive substances," or NPS. When a new product appears, doctors, police and researchers scramble to identify it and determine its origins. Often, within a few years, the drug will be legally banned. In the meantime, though, Dr. Zee keeps coming out with new substances, always staying a few steps ahead.

The approach has paid off. In 2012, for example, Dr. Zee's Amsterdam lab boasted a turnover of roughly 600,000 euros per month. Much of that money, however, was used to pay taxes and overhead costs. Dr. Zee himself earns just a few thousand euros a month, enough to pay for his children's education, cover the grocery bills and put a little bit aside as savings. Still, as is often the case, success inspires envy: jealous competitors, partners and co-workers. Even jealous friends.

Those who know Dr. Zee's real name are able to follow him online on LinkedIn. They know that he is 47, was born in Israel, received his PhD in applied mathematics, and has applied for five patents. He designed algorithms for a large U.S. software company, worked on the "Human Genome Project," and spent time with an Israeli pharmaceutical company. Former colleagues praise him as being "highly talented, interesting, efficient and inspiring."

Nearly all of the legal narcotics developed by the Israeli doctor eventually end up on the desk of Volker Auwärter, head of the forensic toxicology laboratory at the University Medical Center Freiburg inFreiburg, Germany. Auwärter has taken apart and analyzed many an NPS, and warns about the potential dangers they pose. "The drugs are often effective at a very low dosage. Plus we have no knowledge of the accompanying long-term effects," he says.

There have been deaths linked to Dr. Zee's inventions. But it's not clear if the NPS alone caused the fatalities, or if others drugs were also involved. The problem, according to Auwärter and many other researchers, is that there just isn't enough information yet about NPS. Worse still, they say, is that Dr Zee has made Europeans his lab rats.

Tired of playing catch-up with drug designers like Dr. Zee, authorities in Britain, France or Germany have sought legal loopholes to crack down on NPS once and for all. German lawmakers designed laws in 2016, for example, banning the research and sale of entire substance groups — including products that haven't yet been invented. Dr. Zee, as a result, has had to focus on substance groups not included in the ban.

Europeans are his lab rats.

But what he'd really like is to turn the whole NPS conversation on its head, which is why he traveled in February to London's Shoreditch House, where he participated in a private question-and-answer session with 60 of city's young and rich elite. The guests were people who not only know Dr. Zee's products through personal experience but can also function as supporters of his products and use their influenced to lobby for more liberal drug policies.

Dr. Zee acknowledges that his view on the NPS business has changed somewhat — due in large part to concerns expressed by his wife. "My wife and I have the best possible relationship," he says. "She is completely abstinent and, nonetheless, tolerates what I do. But she worries about me when I am high."

Looking at things from her perspective helped him better understand why authorities try to ban NPS. It's because people don't know enough about the substances. They're scared. And yet because of the cat-and-mouse nature of the business, NPS inventors never have a chance to refine the substances, engage in open dialogue about them or educate the public. Instead they go back to the drawing board and come up with new substances. It's a chain of cause-and-effect he calls "default recurrence."

In Dr. Zee's opinion, it's a problem of miscommunication. The consumer doesn't have a chance to explain the deeper reasons why he or she takes drugs. Doctors aren't familiar with studies concerning the drug because it has not been officially researched and registered. And lawmakers want to adhere to their strict anti-drug policies. Dr. Zee wants people to get high safely. But for that to happen, the substances need to be legal, he says.

Dr. Zee promotes what he calls "psycho wellness." He sees NPS as helpful but intoxicating substances somewhere between medication and illegal drugs — drugs for people who have a good life but want to get high on occasion to solve a particular problem, like writer's block or dealing with a stressful superior. It was never about how wonderful drugs are or to make the world a beautiful place, says Dr. Zee — just to make society as a whole function better.

With the help of scientists, investors and the general public, legislators may one day re-imagine the entire approach to drug policy. For Dr. Zee, that would be the best high of all.