Phytokeratin, a plant-based alternative to keratin, is often used in hair care products and formulations for lashes and brows. But what benefits does this ingredient offer to body hair and scalp hair? Find out in this article.
Hair, lashes and brows: the benefits of phytokeratin?
Summary
Published on July 18, 2025, by Sandrine, Scientific Editor — 5 min of reading
Themes:
Focus on keratin present in hair, eyelashes and eyebrows.
Keratin is a fibrous protein organised into hierarchical structures, forming microfibrils in the cortex of hair, eyelashes, eyebrows and other body hair. This structured organisation underlies the strength of hair : in theory, if the scalp allowed, a head of around 120,000 hairs could support a weight of 12 tonnes. Keratin consists of chains of amino acids with a high proportion of cysteine, a sulphur-containing amino acid. The thiol (–SH) groups of cysteine can oxidise to form disulphide bonds (–S–S–), which act as bridges between keratin chains. These disulphide bridges are essential to the cohesion and stability of the hair fibre.
Keratin is abundant in the cuticle, the outer layer of hair, eyelashes and eyebrows. Made of keratinised scale-like cells, the cuticle acts as a protective barrier. The alignment of these cells is essential: when disrupted, the fibre becomes more vulnerable. External factors such as UV radiation, heat or chemical treatments can then degrade keratin, disrupt cuticle cohesion and promote dehydration, breakage or even loss of fine hairs and hair.
Did you know? The disulfide bonds in keratin can be modified. This principle underlies hair straightening and perming. These techniques break the disulfide bonds to reshape the hair, which is then fixed during reoxidation.
The importance of keratin for hair, eyelashes, and eyebrows.
Source: KWON I. K. et al. Human hair keratin and its-based biomaterials for biomedical applications. Tissue Engineering and Regenerative Medicine (2014).
Phytokeratin, a plant-based active ingredient to care for hair, eyelashes and eyebrows?
Keratin underpins hair structure, so its widespread use in formulations is logical. However, it is of animal origin (found in feathers, wool, or hooves), which may deter some people. To address this issue, the phytokeratin has been developed. It is a natural alternative obtained through hydrolysis of plant proteins, such as wheat or almond, which has an amino acid profile similar to animal keratin. By biomimicry, plant keratin could reproduce the effects of animal keratin.
It is important to note that phytokeratin is a recent active ingredient in hair and skincare formulations. To date, no clinical study has directly assessed its effect on hair fibre or on eyelash and eyebrow hair. Its biochemical similarity to animal keratin suggests it may offer similar benefits and may hydrate eyelashes, eyebrows, and hair. Phytokeratin contains hydrophilic amino acids such as glutamine, serine, and threonine, which can bind to the surface of the hair fibre or shaft and form a protective film. Better protected, fibres are less prone to breakage.
Besides its hydrating properties, phytokeratin could provide broader protection against environmental stressors such as UV rays. Although no study has yet evaluated this effect for phytokeratin, results obtained with a hydrolysed form of animal keratin support some hypotheses. A recent study demonstrated photoprotective effects of hydrolysed keratin on the hair fibre. Researchers exposed hair strands to continuous irradiation simulating accelerated solar ageing, after pretreatment or not with a solution containing hydrolysed keratin. Untreated hair showed a significant loss of mechanical strength (−14.32% of tensile strength), while hair treated with hydrolysed keratin was not only protected from this degradation but also saw its stiffness increase by 21.66% after exposure. Although phytokeratin differs from animal keratin, it also consists of short amino acid chains produced by hydrolysis and could therefore have a comparable effect.
Phytokeratin could form a protective film on the fibre surface that absorbs part of ultraviolet radiation and, as it degrades, releases peptide fragments that penetrate the fibre to reinforce its internal structure.
Hair photoprotection with hydrolysed keratin.
Source: CHANG K. et al. Performance and mechanism of hydrolysed keratin for hair photoageing prevention. Molecules (2025).
Sources
KWON I. K. & al. Human hair keratin and its-based biomaterials for biomedical applications. Tissue Engineering and Regenerative Medicine (2014).
MEYERS M. A. & al. Structure and mechanical behavior of human hair. Materials Science and Engineering (2017).
HWANG Y.-S. & al. Keratin-mediated hair growth and its underlying biological mechanism. Communications Biology (2022).
CHANG K. & al. Performance and mechanism of hydrolyzed keratin for hair photoaging prevention. Molecules (2025).
