However, one Springvale dairy manager told the Chronicle: "I know it's bad for you and all that, but it's just business. If it's legal, we sell it."
Staff at those stores selling K2 or similar said they always asked for identification to check the customer was over 18 and kept the product out of view, either under the counter or in a tobacco cupboard.
Several were selling their remaining stock cheap to get rid of it before the law comes into effect on Thursday.
A staff member at the Fairfield Dairy in Springvale said she had ordered $200 worth of K2 from the supplier on Tuesday only to find out about the law change after the stock had arrived.
"We've only been selling it for about two months and now the law's changing. I don't think we'll bother with stocking anything else."
Xiu Fang, from the Polson St Foodmarket, said she had heard of some people having "health problems" after using the product. A worker at a Fitzherbert Ave shop, who did not want to be named, agreed.
This sentiment was shared by the manager of the Alma Road Dairy, who also did not want to be named.
"If we didn't sell it, then the customers would just go to a place that does and buy from them. It's legal, just like cigarettes, so we sell it. Otherwise we lose business.
"They're only making two parts of the K2 formula illegal so the supplier will just replace them and, if there are no problems or complaints, they will sell something new."
The Pylon Dairy sells White Rhino, another synthetic cannabis product, and the shop manager said he wasn't sure if the product would still be legal after the law change.
"We keep a small stock and have it kept out of sight because of that uncertainty. K2 is very popular, but we've never stocked it because of these problems of whether it's legal or not," he said.
However, Alan Stratton, who runs the Kowhai Park Dairy, said he had never sold K2 or any other synthetic cannabis, and had no intention of doing so.
"I'm anti that sort of thing and always have been - I suppose it's because I grew up without it around. When they first started coming out, the suppliers sent out pamphlets talking about the big mark-up on price, and I said, 'I don't care how much I get out of it, I'm not interested in selling it'.
"I get asked for it a lot, though, and it's not just young ones - middle-aged guys come in asking, too."
Melissa Hohaia, a staff member at the Glasgow St Dairy, said the shop had sold the original Kronic but when that was made illegal they stopped stocking similar products.
"It's just not worth the hassle and we don't mind missing out on any money from it."
