Yes, the expiry date guarantees the effectiveness of the active ingredients in the product as well as the quality of correct preservation of the various ingredients. Beyond this date, we no longer guarantee the product's effectiveness. It is therefore preferable to refrain from using the product.
There is also a lifespan after opening the product. Every product has an icon (e.g., an open pot) on the packaging, which mentions the duration of the expiry after opening, expressed in months.