Want to get your hands on a sizable amount of the latest designer street drug? It’s nearly as easy as typing “research chemicals” into Google, exasperated American officials say.

Scroll through an endless list of Chinese Web sites hawking wholesale chemicals at a bargain price, and once you’ve picked your poison — perhaps from a site offering a free sample or touting “big beautiful crystals” — just wire a few thousand dollars to an English-speaking customer service representative on the other side of the world.

The entire ordering process, from start to finish, can take as little as 30 minutes — maybe less, authorities tell The Washington Post. “5-10 days can arrive your address,” one site says.

This is the new synthetic drug trade, a globalized marketplace in which Chinese chemical companies pump out large volumes of ever-changing substances that are too new to be banned internationally, leaving law enforcement officials in America and elsewhere struggling to slow the influx of the drugs (or their primary chemical components).

They’re also coping with the considerable fallout of this new flood of dangerous chemicals; in Florida, for instance, the highly addictive synthetic drug “flakka” is now wreaking havoc in some parts of the state — including giant Broward County, where one major hospital system has reported seeing up to 20 flakka-related emergencies in one day, and where at least 16 deaths have been attributed to the cheap drug since September.

“You’ll see some pretty sophisticated Web sites with everyone in white lab coats, but these are still clandestine operations,” Jim Hall, a drug abuse epidemiologist at Nova Southeastern University in Fort Lauderdale, told The Post. “They’ll say, ‘Oh yeah, we got the best product on the market.’ There’s even blue flakka and red flakka available just so they can distinguish their brand.”

And, Hall added: “If your shipment is seized, some companies will guarantee you another package.”

Packages that aren’t seized will arrive in your mailbox of your choosing a few days later, typically via an express delivery service. To elude U.S. Customs and Border Protection agents, they may be affixed with an ambiguous label, such as “shampoo,” “industrial solvent,” or “cleaner,” officials say.

Hence the daunting challenge facing U.S. authorities struggling to slow a deepening current of synthetic drugs that’s flowing into American cities, where the payoff is immediate and immense. A kilogram of alpha-PVP — the main ingredient in flakka — can be purchased for $1,500 online and sold for $50,000 on American streets, Hall said. Recently, he noted, authorities have intercepted shipments more than 10 times that size.

Complicating the fight against flakka, authorities say, is the fact that the drug is not illegal in China, where labs employ “classically trained chemists” and categorize the drug as a “research chemical,” according to the DEA.

Authorities at the state and federal level said the exact number of labs and chemists producing synthetic substances like flakka — known internationally among health experts and law enforcement as a New Psychoactive Substance (NPS) — is unknown. On the Chinese chemical supplier Web site, guidechem.com, the New York Times found more than 150 Chinese companies selling flakka.

The labs are concentrated in the southern province of Guandong, bordering Hong Kong, due to its history of manufacturing traditional Chinese medicine, which includes natural ingredients that are replicated in synthetic drugs like flakka, according to Quartz.

“We’re talking thousands of labs in China,” Broward County Sheriff’s Detective William Schwartz told The Post. “They’re everywhere, and it’s very common over there, and the exportation laws leave a lot to be desired as far as law enforcement in the United States in concerned.”

A U.S. State Department official who spoke on the condition of anonymity said the problem is that there are thousands of legitimate chemical companies in China; the country’s chemical industry is regulated, the official said, but the scale of the industry and the sheer number of smaller companies makes oversight difficult.

“Traditionally synthetic drugs like Ecstacy spread from Europe,” Guohua Li, a professor of epidemiology at Columbia University in New York, told The Post. “Those were mostly pharmacological laboratories. In China, it’s much more decentralized and the regulation for some of the substances used as key ingredients for synthetic drugs are in a gray area.”

Unlike drugs such as heroin, which take considerable time to produce, synthetic drugs can be made in a rundown factory or a basement quickly and on a mass scale, Li said.

“There is a booming economy for these drugs,” he added. “You can get rich very quickly.”

Chinese exports of methamphetamine, and the chemical compounds used to make it, are an especially frustrating problem, the Times reported. Mexican drug traffickers, who produce 90 percent of the meth used in the United States, are one of the groups taking  advantage of those imports, according to the Times. “They just didn’t see what was in it for them to look into their own industries exporting these chemicals,” Jorge Guajardo, the former Mexican ambassador to China, told the Times.

When Guajardo tried to push Chinese officials to crack down on the problem, they said it was the problem of Mexican customs agents or said his country’s pleas for help had been written or translated incorrectly, the Times reported.

In April, China said it arrested more than 133,000 suspects and seized 43.3 tons of narcotics as part of a four-month operation, according to its state-run Xinhua News Agency. Chinese authorities also said they punished 606,000 drug users during a national anti-drug campaign.

But international officials say campaigns like that barely put a dent in the problem. The Chinese embassy in Washington did not respond to The Washington Post’s requests for comment.

Flakka, the State Department official said, is just one NPS among hundreds being produced by Chinese labs and shipped to countries around the world, often before governments have time to identify and ban the substance.

Authorities say the substances are often tweaked to circumvent existing bans. Substances that aren’t tweaked might be rerouted to a country with more favorable laws.

“We’re up to 500 drugs this year, and the number keeps growing,” the official said. “Often, there’s a very minor chemical change from one to another.”

A similar change gave birth to flakka, authorities say. Formerly sold in gas stations and known as bath salts, flakka was created by chemists to sidestep laws banning the designer drug in Europe and the United States. Authorities sometimes refer to the drug as a “second-generation bath salt.”

“Our supposition is that the original concept was to design it so it would be technically not illegal,” Hall told the New York Times. “It appears they are now looking to also design the molecule to be even more potent and more addictive. Addiction is good for sales.”

The State Department official said more countries, particularly in Europe, are beginning to discuss NPS with the State Department, but the drugs have already emerged as a problem in Latin America, Africa and India. The official said Chinese government officials maintain the drugs are not a problem domestically.

“In a lot of cases, countries aren’t even sure sure what specific drug they’re seeing because they don’t have forensics to identify the drug,” the official said.

Authorities in the United States have the ability to identify illegal substances but struggle to keep pace with Chinese chemists.

Flakka’s main ingredient — alpha-PVP — has been banned in Florida since 2012 and, according to the DEA, is now listed as a Schedule I drug under the federal Controlled Substances Act, meaning it is classified as the most harmful category of drugs, with no applicable medical use.

Gil Kerlikowske, the Commissioner of U.S. Customs and Border Protection, told Reuters that China has increased criminal investigations into synthetic drugs, but the country’s huge ports and expansive territory presents enormous challenges for anyone trying to crackdown on dealers.

The Obama administration has even raised the issue of flakka in talks with the Chinese government, according to the State Department.

The State Department official who spoke with The Post said the two countries are already working together on particular cases when the United States provides Chinese officials with specific information.

“If there is a case here, we pass on the information,” the official said. “We don’t have all the information to indict this person.”

In March, DEA officials arrested a high-level synthetic drug trafficker from China at Los Angeles International Airport. Officials said the arrest of Haijun Tian, who was lured to the United States after one of his top customers became a government informant, is “the centerpiece” of a three-year-long investigation into the production and distribution of synthetic cannabinoids, known as “Operation Poisyn Control.”

“The DEA is working with the Ministry of Public Security (MPS) of the People’s Republic of China, which has initiated its own investigation into TIAN, his associates, and relevant companies,” the DEA said in a statement last month. “The DEA and MPS continue to exchange information in this joint investigation into the manufacturing and trafficking of synthetic cannabinoid compounds and other dangerous drugs.”

Back home, police have also begun arresting Americans importing large quantities of alpha-PVP into the United States. Over the last year, that list has included two men in Wisconsin, a man and a woman in Minnesota and “A nerdy Hunter College student who was vice president of his high school Science Honor Society,” according to the New York Post.

And yet, authorities say, even small quantities of alpha-PVP can present police with enormous challenges. A kilogram of flakka, Hall said, is enough for 10,000 doses of the drug, which can produce a powerful, euphoric high in small amounts.

Flakka has surfaced in Houston, Ohio and Chicago, but southern Florida, with its large addict population and a drug infrastructure built by cocaine, remains ground zero for the drug. In Broward County, there were more than 300 cases of flakka recorded by the sheriff’s office crime lab during the first three months of 2015, according to county figures. In 2014, there were about 200 cases total.

Authorities say that the drug’s murky origins mean users have no guide for dosage, leading to overdoses and erratic behavior. Authorities say they’re also concerned about flakka’s long-term effects. First-time users might take as long as four days to return to a normal state of mind, but repeat users can require weeks, according to Reuters.

Peter Ventre, a psychiatrist at Fort Lauderdale Hospital, told Reuters that a woman in her early 20s who used the drug displayed symptoms “similar to a stroke or brain bleeding.”

“Now she can’t talk, can’t recognize anybody and can’t walk on her own,” he said.

Dennis A. Wichern, Special Agent in Charge of the DEA’s Chicago Division, told The Post that horror stories like those are why the agency will continue to aggressively fight synthetic drugs.

“When you sit down with a family member after they’ve lost a brother or a son or a daughter to one-time drug use or the effects of flakka, it makes it personal,” he said. “This drug preys upon our young people and the most vulnerable people in our population.”