Western Bay of Plenty shops selling legal highs will take a big hit in their profit margins with the Psychoactive Substances Amendment Act becoming law.

From midnight tonight, legal highs, including party pills and synthetic cannabis, will be banned and all remaining products will be stripped from shelves and returned to manufacturers.

Police seen coming out of Special T Discounters on Cameron Road today before the act becomes law tomorrow.

The products will remain off the shelves until they are proven to be low risk. Until then, people face a $500 fine if they are caught possessing a small amount of psychoactive substance.

Possessing a large amount with intention to supply is punishable by up to two years' jail, or fine of $500,000.

Previously there were more than 100 stores in the Bay of Plenty selling psychoactive substances, with as many as 300 different products available.

Now there are only a handful of stores, including Aristocrat Adult Shop in Greerton, Special T Discounters on Cameron Road and Bamboo Barn in Katikati, who have until midnight to get rid of legal highs from their shelves.

Aristocrat Adult Shop owner and legal high licence owner Gloria McCoy says her business will definitely notice a downturn once the law takes force.

'A staff member's job will be lost and our hours will be shorter, other than that there won't be too much [change].

'We've had no hassles, no bother. We have really nice people with the majority of our customers over 30, 40, 50, 60 and 70-years-old.”

From Thursday, Gloria will have to itemise and return all remaining products to the manufacturer.

'We have to prove who had bought it and where it has gone to, as part of our legal requirements.”

Tauranga Police Inspector Karl Wright-St Clair encourages members of the community to report any illegal sales of psychoactive substances.

This call follows the arrest of one man who will appear in court tomorrow for allegedly selling psychoactive substances without a licence.

The 24-year-old Tauranga man was arrested when police executed a search warrant on a retail store in Te Puke on Friday as a result of information received from the public.

Police warn they will be keeping a close on business to ensure the new legislation is adhered to.

Rotorua MP Todd McClay expects the Te Puke community will welcome the ban on synthetics, but warns it could force the drugs into the black market.

Todd says an amendment to the law also means any future product cannot be tested on animals to prove low risk of harm.

'This too is a good result for our community. As minister responsible I put in place a complete restriction on animal testing until an expert committee of scientists and representatives of the animal welfare community had fully considered the issue.

'Scientists say that some level of animal testing would be required to prove these drugs safe, but parliament decided whilst this was acceptable for medicines that could save lives, to test recreational drugs on animals was a step too far.”

Todd says the removal of these drugs and banning of animal testing is an excellent result.

To hear what Tauranga residents thought click here.