Chemist Warehouse Warrnambool and Chemist Warehouse at Gateway Plaza owner Jason Yacoub said his stores were trying as best they could to keep up with the demand.

"Pretty much every customer calling up is asking about masks," he said.

"We're hoping to be restocked daily or every second day.

"We've had to put a two packet per person limit.

"We want to make sure as many people can get their hands on them."

The jump in demand for face masks comes after Premier Daniel Andrews encouraged Victorians to wear a mask if they were out of their house and couldn't maintain 1.5 metres from another person.

"When we say mask it might be one you've purchased, it might be one you've made, it might even be a scarf," he said.

"No mask will bring the risk down to zero, but every type of mask and face covering will mitigate some of the risk. That shouldn't be read as forecasting where we think case numbers are going to go, it should be seen just as a precautionary measure that's pretty low cost and very high benefit.

"Wearing a mask reduces the likelihood of you spreading it if you happen to have it, but not have symptoms, and it reduces the chances of you getting it if you move in a circle of people, if you're in a space you can't maintain that 1.5 metres. Numbers are low in regional Victoria and we want to try and do everything we can to keep them low and wearing masks is just a logical next step."

Direct Chemist Outlet Target retail manager Rachael Earls said face mask sales had increased since last week. "They're not something we usually order in bulk," she said. "We'd sold out of what we'd had by Friday."

She said more orders had been placed and she expected them to arrive in the coming days.

Monaghan's Pharmacy's Sharon Kenna said there had been a rush on face masks sales last week and she was hoping to get more during this week.

"People are coming in and asking about them," she said.

Artz and Kay Pharmacy owner Mary Lou Kay said the demand for face masks had increased but they were able to meet the demand.