A citrus extract used for scent and a 'clarifying' image in shampoos and cleansers. No evidence of a health or hair benefit.
Grapefruit fruit or peel extract adds fragrance and supports marketing about 'clarifying' or 'volumising'. It is not the same as grapefruit seed extract, which is sold as a preservative.
No clinical studies support hair or skin benefits of grapefruit extract at cosmetic levels. It is mainly a fragrance and marketing ingredient.