Allium Cepa Bulb (Onion) ExtractOnion is known to have antibacterial and antifungal activity, it can help to reduce acne and stimulate hair growth. It has been proven as a scar healer that not only improves the cosmetic appearance of scars , but also prevents scarring by wound healing. It's the flavonoids quercetin and kaempferol that might improve your scars by regulating fibroblasts, the cells that help build scaffolding for new tissue.