Most customers notice lashes feeling stronger and looking healthier within 2 weeks. Visible length and fullness typically show up between weeks 4–8 with consistent daily use. Trust the process — this isn't mascara, it's a treatment.

Most best-selling lash serums contain prostaglandin analogs — an ingredient class linked to darkened eyelids, iris color change, and sunken eyes, and the subject of multiple class action lawsuits and FDA warning letters. LashTheory is completely prostaglandin-free. You get the results without the risks.

Prostaglandin analogs are drug-like compounds used in glaucoma medication that were quietly added to many popular lash serums because they dramatically accelerate lash growth. The problem: they can cause permanent side effects including darkened skin around the eyes, hollow or sunken orbital fat, and in some cases iris color change. Brands including Rodan + Fields, GrandeLash, Babe Lash, and RevitaLash have all faced lawsuits over this ingredient. LashTheory uses none of it.

The two heroes are Myristoyl Pentapeptide-17, which activates the keratin gene inside the lash follicle to encourage stronger, longer growth, and Copper Tripeptide-1, which supports follicle health and regeneration. These are backed by hyaluronic acid for moisture, centella asiatica for soothing, panthenol, and vitamin E.

Yes. LashTheory is formulated at the same pH as human tears, is oil-free, fragrance-free, and hypoallergenic. It's one of the few lash serums suitable for genuinely sensitive eyes because it contains none of the harsh compounds that cause most lash serum reactions.

Yes. Remove your contacts before applying, wait a few minutes, then reinsert. The formula is oil-free and won't affect your lenses.

Prostaglandin-based lash serums are classified Pregnancy Category C and are not recommended during pregnancy or breastfeeding. Because LashTheory contains no prostaglandins, it does not carry that classification. That said, we always recommend checking with your doctor before adding any new product to your routine during pregnancy.

There are two steps. First, use the wand to brush serum through your lashes from root to tip — this coats and conditions every lash. Then flip to the precision ball tip and press it gently along your upper lash line to deposit serum directly at the root, which is where growth actually starts. Use morning and night as the last step of your skincare routine.

Absolutely — and many of our customers say the brow results are just as impressive as the lash results. Use the ball tip to apply along sparse or thin brow areas daily.

Like most cosmetic treatments, results are maintained with continued use. If you stop entirely, your lashes will gradually return to their natural baseline over 4–8 weeks. Most customers move to a maintenance routine of once daily or every other day after achieving their desired result.

After. Apply LashTheory as the very last step of your skincare routine so nothing dilutes or blocks absorption at the lash line.

Yes. The formula works on any lash or brow regardless of gender. Short, sparse, or thinning lashes are not exclusive to women and neither is LashTheory.

With twice daily use on both lashes and brows, one tube typically lasts 2–3 months. For lashes only, expect closer to 3–4 months.

This is actually where LashTheory performs best. Lashes weakened or thinned by back-to-back extensions respond well to the peptide and conditioning formula because the follicles are still active — they just need support. Many of our customers started using LashTheory specifically to recover from extension damage.

Yes on both. LashTheory is 100% vegan, cruelty-free, and contains no animal-derived ingredients. It is also free from parabens, sulfates, silicones, fragrance, and harsh alcohols.