If stored unopened under normal conditions, it can be used for up to three years. Under Japan's Pharmaceutical Affairs Act, cosmetics and quasi-drugs that may undergo a change in quality within three years under normal storage conditions
must display an expiration date. InnerSignal has passed a variety of stability and safety tests, and is a product that can be used without worry within a period of three years. That is why the expiration date is not displayed on the product.