Eau yani paani sabse common base ingredient hai skincare mein. Isse actives, humectants aur dusre beneficial ingredients ko dissolve karna aur spread karna easy hota hai. Iska apna koi therapeutic activity nahi hai but without water ke skincare formula work nahi kar sakta. Paani skin ko hydrated rakhne mein help karta hai aur sab ingredients ko properly deliver karne mein zaroori hai.