The primary reason onion extract is used in cosmetics like this hair balm is not for its aroma but for the sulfur-containing compounds and other plant substances it provides. Sulfur is a key building block for keratin, the main protein in hair. These components help condition the hair surface by smoothing the cuticle, which can improve shine and reduce friction that leads to breakage.
Cosmetic formulations carefully process and blend these extracts to integrate their beneficial properties while controlling the final scent profile. The product is designed to leave hair feeling softer and looking neater with a pleasant, light fragrance that dissipates after drying. If you are sensitive to fragrances or specific botanical ingredients, it is advisable to test the product on a small section of hair first.