How long do the blades last?

How often a blade should be replaced is very unique to an individual and the texture of their facial hair. In general, 8-10 shaves seems like a reasonable estimate, although it could be more or fewer. You will notice it's time to change it when the blades are working ineffectively, or if you happen to be getting little cuts more often than is usual. If you do happen to find the blades are beginning to dull, using a shaving oil in lieu of a cream or gel can help the 'slip' of the blade, if you wish to get a little more wear out of it.