Protein: A Building Block of Healthy Hair

Most people know that protein is essential for bodily health and building muscle, but one area that often goes overlooked is its critical role in hair health. Every cell in the body depends on amino acids—the building blocks of protein—which we get primarily through the foods we eat. Once protein is digested, these amino acids are distributed throughout the body to support various functions, including hair growth and maintenance. 

Hair uses significant amounts of protein; approximately 65–95% of our total hair’s weight is made up of protein.¹ At first glance, the relationship between protein and hair might seem straightforward, but the subject is far more nuanced than it appears.

The primary structural component of hair is keratin, a strong, fibrous protein packed with amino acids that help maintain the strength, structure, and overall health of our hair. Keratin includes some amino acids our bodies can make and others, like histidine and lysine, that we have to get from food.² 

Getting enough protein each day helps ensure a steady supply of amino acids for keratin production. General recommendations for daily protein intake range from 0.36 to 0.73 grams per pound of body weight, depending on factors like age, gender, weight, and activity level. For example, if you weigh 170 pounds, that equals about 60 grams of protein per day if you’re not very active, or as much as 120 grams per day if you’re highly active.³ 

The recommended daily value guidelines you see on a label can be a useful starting point, but they don’t account for individual differences, especially if you’re working toward a specific goal, like improved hair growth. Health is dependent on many factors, and our needs can vary widely, so some people may need more protein than others for optimal hair health.⁴ In general, maintaining optimal protein intake, aiming for approximately 20–30 grams per meal per day is a reasonable target for supporting hair health. Studies do reveal that low or deficient protein intake can contribute to hair shedding. ¹³

Our bodies are smart about how they use protein; they seem to prioritize protein for certain needs over others. Even though hair is in constant need of protein to grow and stay healthy, it’s not a high-priority system, so the body may prioritize more important areas, such as our organs, first.^5,6 When protein is limited, the hair may not receive what it needs to thrive.

Protein demands can also increase during certain times, like pregnancy, lactation, illness, post-surgery, during times of intensive exercise, with issues like metabolic disorders, and with age. In these cases, the body diverts protein to more vital functions like tissue repair, which can deprive hair of necessary nutrients.

In cases of severe protein deficiency, hair follicles may stop growing altogether and enter a resting phase, causing significant thinning. While most people don’t experience this level of protein deficiency, research has shown that even moderate levels can impact the protein content of hair.⁷

Given how many factors can impact whether protein is available for hair, it's important to make sure you get enough of this essential nutrient.

To help you meet those needs, try adding a source of animal- or plant-based protein to most meals and snacks, like:

Protein isn’t just for building muscle; it’s essential for the entire body, including hair. Because hair is made with amino acids, a consistently low-protein diet can deprive the body of nutrients, which negatively impacts our hair. 

If you're unsure whether you're getting enough protein, consider consulting a nutritionist or integrative health provider. And if you've increased your protein intake but your hair isn’t where you want it to be, factors like hormones, lifestyle, or stress may also be at play. Ultimately, supporting healthy hair begins with meeting your body’s foundational needs, of which getting enough protein is one of the most important.