The tyre allocation has been tweaked for the Monte Carlo event, where drivers will have two sets of each tyre compound.
Previously, drivers had three sets of the harder compound and one set of softs for the weekend.
Also for the Monaco weekend, the series' bosses have decided to scrap the rule saying drivers had to save a set of the harder tyres for the sprint race.
Pirelli is hoping the new rules will generate a greater variety of strategies during the races.
"The new tyre rules for GP2 are an exciting development that will introduce a bigger element of tyre strategy and management to the race weekend, making the GP2 Series even better preparation for the very pinnacle of racing," said Pirelli's racing manager Mario Isola.
"With two sets of the softer compound available to them at any point in Monaco, the GP2 drivers will need to think really carefully about when to use them, but they will end up with more experience of running on a faster compound, which needs to be wisely managed."