Can the M2 Eyelash Activating Serum (EAS) be used more than once a day?
We recommend that you use the serum once a day. We have established that the serum does not yield better results when applied repeatedly.
https://www.m2beaute.com/en/eye-care-faqs/lash-serum-faq-eyelash-activating-serum/can-the-m2-eyelash-activating-serum-eas-be-used-more-than-once-a-day