The man – with a distinctive piercing – entered the shop and threatened the man behind the till with what was described as a handgun.
The offender stole a small sum of money and painkillers including temazepam, pethidine, morphine, bottles of oxycodone and central nervous system stimulants concerta tablets and equasium tablets.
No one was hurt during the incident.
The raider is described as white, in his early to mid-30s, 5ft 2ins tall of stocky build with broad shoulders and stubble.
He had an earring in his left ear – which had stretched his ear lobe – and had a tattoo on his neck.
He was wearing a dark zip-up baggy jacket, a beanie hat and black footwear.
At the time of the robbery, the nearby Peakirk-cum-Glinton CofE Primary School was finishing for the day and Detective Constable Rich Oliver is appealing to parents picking up their children if they remember seeing anything suspicious.
Anyone with information should
