With this in mind, it is normally recommended to fill your eyelashes every two to three weeks. Since everyone's eyelashes and goals are different and therefore require different levels and types of regular maintenance, it's key to have a strong and open sense of communication with the eyelash technician. Therefore, to keep those eyelashes looking delicious, it is recommended to fill in an average of 3 weeks apart. Some people have faster or slower growth cycles.
There are several factors that can cause these extensions to come off prematurely. Ideally, your client should come every two to four weeks, but longer wait times may mean longer treatment time, as more eyelashes will need to be filled. The bond between the client's natural eyelashes and the eyelash extension weakens over time due to oil or other impurities.