Quinoa protein, derived from the seeds of Chenopodium quinoa, is increasingly used in hair care formulations such as shampoos, conditioners, and masks. The justification for its use is supported by some scientific evidence, though this is still limited and primarily based on in vitro and cosmetic studies rather than robust clinical trials.

Quinoa protein is rich in essential amino acids, particularly lysine, which is less common in other plant proteins. These amino acids can help support the structure of the hair shaft. Several laboratory and cosmetic science studies have demonstrated that hydrolyzed quinoa protein can form a protective barrier on the hair, reducing cuticle damage and improving hair strength, smoothness, and shine. For example, a study published in the International Journal of Cosmetic Science (2014) found that hydrolyzed quinoa proteins improved hair combability and protected hair from damage caused by washing and styling.

However, the effects are primarily cosmetic—improving the appearance and manageability of hair—rather than addressing underlying hair health or growth. There is limited evidence from clinical studies in humans regarding long-term effects or benefits beyond surface protection. Thus, while the use of quinoa protein in hair products is scientifically plausible for topical, cosmetic benefits, claims about supporting overall hair health or growth are not strongly substantiated.