Best Lash and Brow Serums for Growth and Thickness

Full lashes and thick brows are no longer just a trend; they’re a true confidence booster and makeup essential for people everywhere. The market continues to expand, innovating new formulas that promise visible results, from longer lashes to denser brows, without the cost or hassle of salon treatments. Those seeking lush brows and fluttery lashes often want a boost that’s easy, effective, and safe for everyday beauty routines.

For anyone looking for a trusted solution, check out Rodan + Fields for expertly formulated lash and brow-enhancing products.

The Science Behind Lash and Brow Serums

Growth serums work by nourishing the hair follicles and sometimes extend the hair growth phase, leading to thicker, longer lashes and fuller brows. The only FDA-approved ingredient for eyelash growth is bimatoprost, commonly found in prescription products like Latisse. Most over-the-counter serums combine peptides, amino acids, and botanicals to condition and strengthen hairs rather than promise miraculous growth.

Itching for results? Studies show some serums deliver visible improvements within 4–8 weeks, while others primarily hydrate and minimize breakage.

Essential Ingredients and Active Compounds

Bimatoprost: Strongest scientific support for lash growth, but only available by prescription in the U.S..
Peptides and Amino Acids: Strengthen and fortify lash and brow hairs, commonly featured in leading serums, and hold about 37.4% market share in 2025.
Biotin, Vitamin E, Botanicals: Condition, nourish, and sometimes appear in cleaner, gentler formulas for sensitive eyes or skin.
Prostaglandin Analogues: Present in some serums and said to mimic growth hormone activity, but formal research is still ongoing and not every formula includes them.

Do Growth Serums Actually Work?

According to dermatologists and recent studies, efficacy depends on the active ingredients and consistent application. While prescription bimatoprost shows proven lash growth, many over-the-counter serums boost thickness and sheen rather than outright growth. Conditioning ingredients like hyaluronic acid or castor oil are great for strength and shine but offer “maybe” results for true length.

Key Facts

Most users notice fuller, stronger lashes or brows in four to six weeks with daily use.
Prescription formulas can yield a 25% increase in lash length within two months, based on clinical studies.
Over-the-counter serums featuring peptides and amino acids help reduce breakage and promote healthier hair appearance.

How To Choose the Right Serum

Picking the best serum is simple when focusing on your needs, sensitivities, and goals. Always check for:

Ingredient List: Look for peptides, amino acids, biotin, and natural oils before artificial fragrances and preservatives.
Safety Profile: Opt for serums tested for irritation (especially near the eyes) and read real user reviews.
Visible Results: Many sponsored reviews cite changes in fullness, but dermatologists recommend looking at measured, clinical results rather than only testimonials.
Clean Beauty Claims: Growing consumer demand for “clean” and “vegan” formulas is shaping the market, with formulas designed for sensitive skin or eyes increasingly available.