This might be a question that not a lot of people think about. However, the supplies in your first aid kit won’t be of good quality forever. Usually, medications will be the first thing to expire within your first aid kit. A new kit will often last for around a year before supplies inside will begin to expire. However, how long your first aid kit lasts will differ depending on the type of supplies that are provided. Once you receive your kit, it is always important to double-check the expiry dates, to ensure everything is still in date before you go out and to use it.