By Hannah Morrison
Police are cracking down on cutting agents used to thin cocaine
Street cocaine has dropped sharply in strength over the last few years, a Newsbeat investigation has found.
We're being told dealers are bulking it out with other potentially dangerous chemicals to make more money, including a drug that has been linked to cancer.
The Forensic Science Service (FSS) tests a lot of the drugs seized by police in the UK.
In 2004, the cocaine brought in to their labs was on average 43% pure. Now half of it is less than 20% pure and increasingly as low as 5% pure.
Dean Ames is a scientist at the FSS and has noticed less and less cocaine in the batches being brought in.
"It's the other materials that are present which will be the dominant components.
"The cocaine is very much a minor component now.
"This lower purity cocaine is being targeted at younger people and the higher purity tends to be targeted to a different market."
On a night out in Liverpool, clubbers told us they had noticed a difference.
One said: "The quality of it has completely dropped. It won't last as long. You go straight to a downer.
"You need a lot more, you spend a lot more money to get the right effect and you still can't get the buzz."
"I don't take it anymore because it's all talcum powder and paracetamol."
It's not the talcum powder that is the concern though.
It's the other stuff that's being added to the cocaine, namely Phenacetin.
It is a painkiller that is no longer licensed to be used in the UK, after tests on animals suggested it may cause cancer.
It's found in 70% of the coke seized in London.
The Serious Organised Crime Agency (SOCA) is now trying to clamp down on the rising trade in cutting agents like phenacetin as well as tackling the illegal cocaine market.
Tony Saggers works for SOCA and is worried users don't know what they're taking.
He said: "You are snorting a powder up your nose that may contain a substance that the British pharmaceutical industry doesn't see fit to use at the moment."
Dean Ames of the Forensic Science Service tests a cocaine sample
The increasing price of imported cocaine is thought to be to blame for the drop in the purity of the drug once it reaches the street.
Dealers have to pay more to buy it wholesale now, but instead of passing that cost on to their customers, they are keeping their prices low but thinning the Class A down.
The cost of a gram is actually getting cheaper because the quality is so bad.
Tony Saggers says that makes it more accessible to people who it would have been too expensive for before.
He said: "People will use what is available to them at a price they can afford.
"What these new cutting agents are doing is making cocaine potentially affordable to a wider group of people."