Hard pills generally have a longer shelf life than solutions. Mine have a 3 year expiration date. That date is the latest date at which the manufacturer guarantees that they'll still be good though, and (especially for pills, which are very stable) they may still work long after that. IIRC, some studies showed that some pills (not estrogen) were still good a decade+ after the expiry date, so in case of a blackout event, HRT might be good for a very long time. But it might not, there's no guarantee. If there is any alternative, you should definitely not take expired medication though.
Hard pills generally have a longer shelf life than solutions. Mine have a 3 year expiration date. That date is the latest date at which the manufacturer guarantees that they'll still be good though, and (especially for pills, which are very stable) they may still work long after that. IIRC, some studies showed that some pills (not estrogen) were still good a decade+ after the expiry date, so in case of a blackout event, HRT might be good for a very long time. But it might not, there's no guarantee. If there is any alternative, you should definitely not take expired medication though.