New, homemade drugs are on the rise in Australia, leaving authorities worrying about a spike in lethal overdoses.

But a group of Sydney researchers have developed life-saving new tests to help identify and treat the "flood" of these designer drugs.

In their quest to circumvent drug laws, organised criminals are increasingly turning to manufactured substances that mimic the effects of existing drugs.

Overdoses of these novel drugs are harder for doctors to treat because they often can't detect what substances have been taken, UTS professor of forensic toxicology Shanlin Fu warns.

"The number of Australians who are hospitalised or die from accidental drug overdoses continues to rise," Prof Fu said.

"There is a flood of the new substances reaching our shores.

"The need for effective drug testing methods has become increasingly urgent."

Designer drugs are often much stronger and deadlier than traditional counterparts and can include a mix of several illicit substances.

As a result, users often don't know what they are taking, increasing the risk of fatal overdose.

There is hope three new tests developed by Prof Fu and his colleagues at the UTS Centre for Forensic Science will provide authorities with a vital new tool in their kit.

Usually, drug testing requires a baseline to compare against, which is made complicated by designer drugs for which no reference standards exist.

But the new tests, which show up "bath salts", fentanyl and a form of hallucinogen, will allow medical practitioners to identify within minutes what substance is present in a sample.

"Until we developed these tests, they often slipped through the law enforcement net," Prof Fu said.

An analysis of wastewater over the 2021 New Year period revealed 16 different designer drug substances in Australia.

Out of the eight countries involved in the study, only the Netherlands used more designer drugs than Australia.