Southeast Asian drug cartels are diversifying the narcotics they produce, the UN's crime agency warned Wednesday, with more than 160 new highs hitting the market in the last eight years.

The Golden Triangle -- where Laos, southern China, Thailand and Myanmar intersect -- is the world's second largest drug producer after Latin America.

It is notorious for churning out heroin and methamphetamine.

But cartel chemists are now also making new drugs to hook customers on cheap compounds that have yet to be made illegal.

So-called New Psychoactive Substances (NPS) are appearing at an alarming rate with 168 new drugs detected since 2008 across 11 Southeast Asian nations and China, according to a report released Wednesday by the United Nations Office of Drugs and Crime (UNODC).

"The world of drugs has become much more complex," Martin Raithelhuber, an expert on synthetic drugs at the UNODC, told AFP.

"We are seeing a lot of new substances around, substances you may not even have heard of but they're there."

While heroin and meth remain the product of choice for the region's narco-gangs, new substances are fast emerging with just three detected hitting the streets in 2008 compared to 80 last year. 

The new compounds act as stimulants, hallucinogens, sedatives and opioids and can be taken alone or cut with existing drugs on the market to save costs or intensify the high.

Many NPS are so new that governments struggle to ban them -- and when they do chemists can simply tweak the formula to create a fresh compound with similar properties. 

With little research on new highs, the risks to the user rise.

One of the most famous new highs in recent years is fentanyl and its many derivatives. 

An opioid that is 100 times more powerful than heroin, fentanyl is wreaking havoc across North America.

An estimated 2.6 million Americans are hooked on prescription opioid painkillers with 33,000 fatal overdoses a year. 

Raithelhuber said most of the new highs detected in Southeast Asia, many of them fentanyl type substances, were aimed at European or North American consumers.

But some of the new compounds were turning up in drugs for the domestic market.

In Thailand and Malaysia ecstasy tablets are increasingly been cut with chemicals like ketamine, mephedrone and alpha-PVP.

Meanwhile tablets in Indonesia are turning up with PMMA and DOC, new compounds with similar properties to the active ingredient of ecstasy: MDMA. 

Source: AFP