Using any medical product beyond its expiration date is not recommended due to potential risks in terms of safety and efficacy. The expiration date is determined by the manufacturer to ensure the product's effectiveness and safety when used. After this date, the chemical composition may change, potentially reducing its effectiveness or causing adverse reactions. For PRX-T33, which is a chemical peel, using an expired product could result in decreased efficacy or unexpected skin reactions. I strongly advise consulting with a dermatologist or healthcare professional before using the expired product. They can provide guidance and suggest alternatives that will be safe and effective for your skin care needs. If you have further concerns or questions about skin treatments, feel free to reach out to a dermatologist for personalized advice.