There are 2 issues here. i am assuming you have glycolic acid but you don't say. Peels are acid in water and the water evaporates leaving a more concentrated solution so it is out of date. Also, at home chemical peels are a bad idea. side-effects do occur and you are not experienced with acid so you should have a chemical peel done by a medical professional
Although this peel kit should not cause harm to you, the potency of the Glycolic Acid is certainly less effective due to its expiration. There are so many great options now for at home peeling systems, I would recommend opting for a newer kit to ensure optimal improvement in skin tone and texture.