At Lamberts, all of our labels include a best before end (BBE) date, based on extensive testing and supported by a valid scientific rationale. Up until the BBE, the product will still contain the nutrient levels detailed on the label (with a few percent difference permitted each way). Whilst supplements are rarely seen to become unsafe after the BBE date passes, it may be that they become less potent, due to the natural process of nutrient degradation.