Can I add anything to a gallon of matte paint to make it gloss paint?

I have a gallon of paint that's the color that I want my bathroom to be, but it's a matte finish. Am I S.O.L. or is there some kind of additive I can use?Can I add anything to a gallon of matte paint to make it gloss paint?
As far as I know there is nothing you can put in the paint to make it glossier. You can try a glaze coat after the base coat has dried or mix four parts paint to one part glaze. This technique is usually done with faux finishes like sponging or ragging.Can I add anything to a gallon of matte paint to make it gloss paint?
I would suggest getting a clear coat, or polyurathane and putting a coat over the colored one.