Game with power-up that boosts stats,How can i make it where it only saves original stats?

I'm working on a game that has power-ups you can use that boost your stats but I don't want stats to save while they are multiplied or added to.

Example: 2x Stat multiplier for 10 minutes.

It would be a great help if somebody could explain a way you can use a power-up for however long but it saves the original stats instead of the power up one, because you are able to earn stats while powered up.

Sorry if the explanation is kinda messy I just don't know how to explain this problem that well.