Amino acids are the molecular building blocks of all proteins, including collagen, elastin, keratin and enzymes vital for skin structure and function. There are 20 standard amino acids, each with unique properties that determine protein shape, flexibility and biological activity. In collagen biosynthesis, glycine, proline and lysine are key, forming the repeating sequences that stabilise collagen’s triple-helix structure.
Plant-Origin Principle
All amino acids originate from plants. Through photosynthesis and nitrogen assimilation, plants synthesise all 20 amino acids using carbon, hydrogen, oxygen and nitrogen from the environment. Animals, including humans, cannot make all of them; we rely on dietary intake directly from plants or indirectly through animals that eat plants.
This principle underscores the nutritional foundation of plant-based skin health: every amino acid that builds human collagen, enzymes and hormones ultimately begins in the plant kingdom.
Essential vs Non-Essential Amino Acids
Humans can synthesise 11 amino acids internally, but 9 are “”essential”; they must come from diet (e.g., lysine, threonine and tryptophan). The long-held idea that plant proteins are “incomplete” has been scientifically refuted. As long as a varied, whole-food diet is consumed, the body’s amino acid pool ensures a continuous balance of all amino acids needed for protein synthesis, including skin and collagen formation.
Amino Acid Pool
The amino acid pool is a dynamic reservoir within the body containing all available amino acids from food digestion and protein turnover. It enables the body to draw upon whichever amino acids are required for new protein synthesis, from structural proteins like collagen and keratin to signalling molecules and enzymes. This system makes precise “protein combining” unnecessary, as amino acids are constantly being recycled and redistributed.
Relevance in Skin Nutrition
For practitioners, amino acids represent the nutritional language of skin renewal. Supporting their optimal supply through diverse, plant-based proteins, alongside cofactors like vitamin C, B6, copper and manganese enhances collagen synthesis, cellular repair and dermal resilience.
Understanding amino acids also bridges disciplines, linking nutrition, dermatology and cosmetic formulation through shared biochemical foundations.
Understanding amino acids also bridges disciplines, linking nutrition, dermatology and cosmetic formulation through shared biochemical foundations.
Continue your professional learning.Explore the Skin Nutrition Science Glossary, a growing resource designed for practitioners in aesthetics, nutrition and wellness science.
Article by Star Khechara
Professional agehacker, author, speaker, founder of skin nutrition institute
About me
Ex-skincare formulator and beauty author turned skin-nutrition educator: Star distilled her 20+ years of skin-health knowledge into the world’s first international accredited skin-nutrition school to teach skin therapists, facialists, face yoga practitioners and estheticians how to help their clients feed the skin from within for cellular-level rejuvenation and vibrant beauty.
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