The Ordinary's peptide serum is a crowd favorite—and we get why. It's affordable, well-formulated, and loaded with branded peptide complexes. But when it came to real-world brow filling, we saw more buzz than breakthrough.

The clear, water-based formula includes an impressive list of complexes. On paper, it reads like a science-backed powerhouse. In practice, it worked better on lashes than brows, and required twice-daily use with a full four-week wait to notice any difference.

If you're looking for a clean, no-frills serum with a focus on prevention over transformation, this one might fit. But for filling visible gaps or reviving sparse tails, we didn't see the wow factor they hoped for.

GrandeBROW is a popular name in the brow world, known for its flashy packaging and big promises. It claims fuller, bolder brows in 6–8 weeks, with clinical backing and a well-rounded blend of peptides, amino acids, and hyaluronic acid.

But during our testing, results were slow and inconsistent, especially for users with advanced thinning or hormonal loss. While some users noticed mild thickening, others saw little change even after 4 weeks of daily use. The formula also contains isopropyl cloprostenate, a prostaglandin analog that may raise red flags for users with sensitive skin or health conditions.

It's not a bad product—but at this price point, we expected more noticeable results.

The drugstore go-to for quick grooming, e.l.f.'s Clear Brow & Lash Mascara is more of a styling gel than a growth solution. Its dual-ended design helps tame unruly hairs and adds a glossy finish, but don't expect any real changes in brow density or thickness.

It's a solid choice for budget-conscious buyers who want definition, not regrowth. As a daily styling tool, it does the job. But in a lineup focused on results, this one sits firmly in the cosmetic category—not the treatment lane.

I was hopeful about RapidBrow, especially after seeing the impressive lineup of ingredients like peptides, biotin, keratin, and even apple fruit cell extract. It promises fuller, healthier brows in as little as four weeks with continued results over three months.

While it did make my brows feel slightly more conditioned and gave them a bit of shine, the actual regrowth was underwhelming. The formula also includes isopropyl cloprostenate, a prostaglandin analog that made me a little uneasy due to the potential for irritation or side effects around the eye area.

Overall, it's a decent pick if you're looking for a conditioning boost, but it didn't deliver the kind of thickening or filling power I was hoping for.

Kosas Grow Potion definitely wins on branding—it's sleek, clean, and packed with trendy ingredients like peptides, hyaluronic acid, and vegan keratin. It's also one of the few prostaglandin-free serums that's marketed for both lashes and brows, which I appreciated.

But as much as I wanted to love it, the performance just didn't match the promise. While it did leave my brow area feeling soft and hydrated, I didn't see significant thickening or new growth, even after a few weeks of consistent use. It felt more like a lightweight conditioning serum than a true growth booster. It's a nice clean-beauty option, but not the most effective if you're trying to actually fill in sparse areas.

RevitaBrow has a luxury label, a touching backstory, and a long list of awards, but in practice, it didn’t live up to the reputation. The formula is packed with peptides, plant extracts, and biotin, yet the results felt underwhelming for the price.

More concerning is the inclusion of cloprostenol ethyl amide, a prostaglandin analog linked to reported cases of irritation, bald spots, and brow shedding. For a product at this price point, the risk just didn’t feel worth it, especially with newer, gentler options available.