In general, most eyelash extensions that are applied in the salon last between two and four weeks. This takes into account that some lashes will fall out prematurely, especially in the first few days. Actually, this is more of a personal question. The answer is only as long as you want to use them.
Natural lashes usually take a couple of weeks to grow and tend to thin out as they grow. Generally speaking, you can get away with wearing false eyelashes for up to five days. After that, the lashes will start to lose their shape and may shed their natural lashes. Depending on the adhesive and the skill used to apply the false eyelashes, they can last between 3 and 7 days.
However, some brands such as Ardell will say that you should wear them for up to 12 hours in a row. Even if you're diligent and clean them after each use, the more intense cleaning process will add extra wear and tear to the eyelash hairs. So you want big, fluffy and spectacular lashes? You're going to have to look beyond the mascara tube and focus on the fake ones. They can be removed, reapplied and used several times before they are no longer suitable for use.
If you use heavy or improperly made false eyelashes, they can put unnecessary pressure on your natural lashes and cause them to fall out prematurely. If you decide to use false eyelashes every day, it's important to take good care of them and let them rest from time to time. It's a simple fact of life that if you use false eyelashes and your natural lashes are thinner. So, if you want to use false eyelashes without damaging your natural ones, be sure to handle them with care and choose high-quality lashes that won't damage your delicate lash line.
It's important to take care of your lashes between uses using serums or eyelash oils to keep them healthy. Another reason is that using false eyelashes is more complex for natural lashes to regain their full length after using them for a few days. Even if you clean and store them carefully between uses, synthetic lashes will start to degrade after four or five applications. However, most users who use this type of adhesive usually do so the night before using their eyelashes.