Hubba Brow Serum brow enhancing serum. Improve the appearance of brow volume in just 4 weeks. Brows look fuller, healthier, natural, and nourished over time. Clinically tested, gentle, and suitable for sensitive skin clinical assessment on 31 participants after 4 weeks of use. WHY WE LOVE IT HUBBA, HUBBA! Get excited! Hubba Brow serum improves the appearance of brow volume in just 4 weeks and shows fuller-looking brows at 12 weeks. The clinically tested, gentle formula contains an efficacious blend of vitamins, plant extracts and rice protein , is suitable for sensitive skin, and feels comfortable on brows. Brows look healthier, natural, and nourished over time. Plus, the wand features a flexible microbristle tip. Non-comedogenic. Ophthalmologist-tested. REAL Results. 93% said it improves the appearance of brows after 4 weeks. 92% said brows look healthier after 4 weeks. 96% said brows look nourished after 4 weeks. 96% said brows look fuller after 12 weeks. 93% said brow hairs feel stronger after 12 weeks. 97% said brows feel conditioned after 12 weeks. clinical assessment on 31 participants after 4 weeks of use. self-evaluation by 124 participants. self-evaluation by 129 participants. Results may vary. BROW FUEL Provitamin B5 helps condition and improve the sheen of brow hair. Biotin & cassia alata leaf extract help improve the appearance of brow hair.