I think that some products will have a “best used by” date on the package if they have natural ingredients that might go rancid. But, I don’t think that hair products are required to provide an expiration date. For me, I just go by the smell test to see if the product is still good. If it smells the same as when I bought it, then I’ll keep it. If it smells musty, moldy, or just yucky, then I say toss it. I hope this helps.