Smoking cannabis makes men get the munchies, while women have stronger pain relief effects from the drug, researchers have found.

Scientists from Washington State University looked at the difference between tolerance and addiction between men and women who smoke marijuana.

Findings in the journal Drug and Alcohol Dependence showed female mice were 30% more sensitive to pain-relieving effects of TCH – the active ingredient in the drug – than males. This, researchers said, could increase vulnerability to side effects of cannabis including anxiety, paranoia and addiction.

The results showed tolerance to THC was far higher in females than males, meaning they needed larger doses to achieve the same effect.

Study author Rebecca Craft said since the drug has been legalised for recreational use in a number of US states, there is a greater need to understand the effects of cannabis, adding most current research has been done on men.

She said the only THC effect more pronounced in men than women is the 'munchie effect', which boosts the appetite.

Researchers believe the difference in how cannabis effects females is due to oestrogen.

"What we're finding with THC is that you get a very clear spike in drug sensitivity right when the females are ovulating - right when their oestrogen levels have peaked and are coming down," Craft said.

She also noted recreational marijuana has far higher concentrations of THC than previously through selective breeding.

"Marijuana is very different than it was 40 years ago. It's much higher in THC and lower in cannabidiol, so a little bit goes a very long way," Craft said.

"We're more likely to see negative side effects today like anxiety, confusion, panic attacks, hallucinations or extreme paranoia. And women are at higher risk."