Lash Extensions are semi-permanent so they will last as long as your natural growth cycle of your lashes. So when your real eyelash falls off, so will the extension. That is typically a couple months. That means you will have to have maintenance which consists of filling in the ones that you have lost. The first initial visit will take about and hour and a half as I attach each extension individually. Fill ins will take about a half hour. After you have your extensions you may not use oil based products on your eyes, including mascara. There is a special water based mascara that you will need to use, although typically you will not need mascara because they look fabulous on their own!!