Onion black seed hair serum is a hair care product that combines the nourishing benefits of onion extract and black seed oil. This serum is designed to help improve the overall health and appearance of the hair, particularly for those experiencing hair thinning, breakage, or hair loss. Onion extract contains , which is known to promote production and improve blood circulation in the scalp. This can help stimulate hair growth and reduce hair breakage and thinning.