Protein for hair growth is sometimes recommended as a treatment for people who wish to prevent hair loss. Using foods rich in protein for hair growth is often encouraged as a holistic alternative to chemical treatments to strengthen hair, as well. Some health practitioners even recommend specific foods to promote hair health, such as salmon and flaxseed.

Healthy hair largely requires a sufficient intake of protein, as most of the hair itself is made up of this nutrient. The protein found within hair cells is known as keratin, and is directly responsible for the composition of each strand of hair. The amount of protein each person needs daily varies on an individual basis by weight, height, and other factors. Persons with weak immune systems or illnesses, such as anemia, may require more. An average person requires between 1.4 to 2.5 ounces (40 and 70 grams) of protein daily.

Prevention of hair breakage is another reason people employ protein for hair growth. When hair breaks, it often does not grow to its full length. If hair has a tendency to break, other efforts used to help make hair grow may still fail. An adequate protein intake strengthens hair, making it stronger and less apt to break.

A severe protein deficiency can sometimes result in hair loss. Most people who have regular access to a wide variety of food, however, will not suffer from hair loss due to a lack of protein in the diet. Such cases of hair loss are typically associated with malnutrition due to a lack of food overall. Hair loss that happens solely because of a lack of protein in the diet is very rare. Most cases of hair loss can be attributed to illness, injury, or stress.

To ensure that one consumes enough protein for hair growth, a high-protein diet can be planned. Eggs, salmon, and liver are popular choices to obtain protein. Dairy foods, such as yogurt and cottage cheese, or whey protein, may be options for those who abstain from eating meat. Protein shakes meant to serve as meal supplements or dietary aids can provide an extra helping of the nutrient as well. Other good sources of protein for hair growth include brewer's yeast and wheat germ.

In addition to eating more protein, people can purchase protein-based hair care products to provide their hair with more protein. These include conditioners, spritz-on treatments, and hair lotions. Both keratin and animal protein may be found in these products.