For how long should I use the M2 Eyelash Activating Serum?
If you want to maintain the length of your eyelashes, you should use the Eyelash Activating Serum regularly. If you stop using the Eyelash Activating Serum, your eyelashes will return to their original length after around eight weeks.
https://www.m2beaute.com/en/eye-care-faqs/m2-beaute-eyelash-activating-serum/for-how-long-should-i-use-the-m2-eyelash-activating-serum