The stand-up and show regular told Digital Spy that some comics do not return because they are unhappy with the free-for-all format of the show.
Asked if the panel show is too adversarial or 'male', Parsons said: "There have been some fantastic female guests, but not all of them have wanted to come back. It's recorded for three hours and it gets boiled down to half an hour.
"Within that time you can feel that you've done some really good stuff but you'll never see it in the actual edit. So certain people have not been happy with how the edit's gone."
He added: "It is the only panel show where you don't get asked individual questions. They'll never go, 'Andy, what do you think?'
"There's always just a little comedy topic chucked up in the air and you've got six hungry comics going for it.
"And often you'll find there's seven hungry comics, because [host] Dara [O'Briain] will chuck the topic up in the air and in fact answer it himself - he's a very shrewd man... very shrewd!"
Andy Parsons releases new stand-up DVD Gruntled on November 14.
> Read Digital Spy's full interview with Andy Parsons
Watch a clip of Mock The Week below: