Is the M2 Eyelash Activating Serum (EAS) safe to use on the bottom eyelashes too?
We recommend that you apply it to the top eyelashes only. All of our tests were conducted in this way, yielding the results described. When your bottom and top eyelids come into contact with each other when you are asleep, some of the Eyelash Activating Serum (EAS) is transferred to the lower eyelashes. Additionally applying the serum to the bottom eyelid would not lead to better results because the active agents are automatically transferred to the bottom lashes.
https://www.m2beaute.com/en/eye-care-faqs/lash-serum-faq-eyelash-activating-serum/is-the-m2-eyelash-activating-serum-eas-safe-to-use-on-the-bottom-eyelashes-too