Lash serums are on the market to help your natural lashes with thickness and length as well as grow new lashes. Dr. Gretchen Frieling explained to Byrdie, "Lash serums are growth-enhancing formulas that stimulate lash growth ... when applied regularly, the lash serum extends the telogen phase of growth, lengthening the lash growth cycle. This will keep lashes thicker and stronger." Most of the lash serums you see will have peptides and collagen, but they may have oils and other ingredients that could dissolve your eyelash extension.

According to Plume Science, your lash serum should not contain mineral, vegetable, coconut or canola oil, as it could weaken the eyelash extension. They also suggest avoiding glycols, a solvent used in many cosmetics. Their own Lash & Brow Enhancing Serum is great to use with an extension as is Clementina Richardson's serum, specifically made to be used with extensions on. Read the label and check with the lash artist before we buy anything. But for the most part, you can use lash serums with extensions as long as they avoid certain oils and glycols. You could also ask your provider about Latisse, the only FDA-approved lash serum that's prescription based and safe with eyelash extensions (via Divine Lashes).