A table full of protein-rich foods

Protein Sources for Hair Growth: An In-Depth Guide for Omnivores, Vegetarians, and Vegans

If you’ve followed my blog for any length of time, you know that I preach the benefits of a healthy, balanced diet.

A diet that falls into the above guidelines contains three main building blocks: carbohydrates, fats, and proteins.

Unfortunately, our busy lifestyles can make it difficult to ensure we’re getting the right balance of nutrients and minerals. But if you’ve been neglecting your protein intake lately, you may be suffering from the side effects now.

So you may be asking:

“Can low protein intake cause hair loss? And if so, is it reversible?”

This article will answer those very questions, so let’s jump right in!

The Hair Strand’s Structure

Before we can get into why protein is important for hair health, you’ll first need to know how the hair strand is structured.

Here’s a simple breakdown.

There are three parts of the hair strand: the cuticle, the cortex, and the medulla (1).

A diagram showing the hair's structure

The cuticle is the outermost part of the strand.

This part consists of scale-like cells that overlap, and they make up what you see of a hair strand when examined under a microscope.

These ‘scale-like’ cells are actually dead cells which have overlapped and which create a protective layer around the hair shaft.

The next layer is the cortex, and it resides in the middle of the hair strand.

The cortex actually has many functions, though its most important is to provide the strand with strength and elasticity.

The cortex is what protects your hair against constant breakage and split ends.

Within the cortex is where you’ll also find the pigment (melanin), which determines the color of your hair.

But perhaps the most important thing to note about the cortex is that it contains the majority of the hair’s protein – keratin. I’ll dig into that more a bit later.

Finally, the innermost layer is the medulla.

Unlike the cuticle and the cortex which are found in all hairs – i.e. terminal and vellus – the medulla is only found in thick hairs.

Even more interestingly, the pattern of the medulla can vary from person to person and even from hair strand to hair strand.

That’s right — the medulla isn’t just a single line that “fills” the hair strand from root to tip. Instead, it can have many patterns including solid, dotted, and fragmented.

Keratin: The Backbone of Hair

I’ve mentioned keratin very briefly above, but it actually deserves its own section.


Because keratin makes up the bulk (about 90 percent) of the hair strand’s weight. And it’s also the main protein within the hair.

The structure of keratin
The molecular structure of keratin.

So, what does it do?

Keratin is a fibrous structural protein that’s often associated with the hair, skin, and nails.

This protein actually plays a significant role in damage control and prevention (2). This means it lends itself to your hair’s tensile strength, or the ability of your hair to resist breaking under pressure.

Protein Deficiency and Hair Loss

It’s well known that nutrient and mineral deficiencies – such as iron, or calcium – can have a negative impact on one’s health.

But did you know a protein deficiency can have the same negative health effects, and it can also lead to hair thinning and loss (3)?

Proteins are an important component of every cell throughout the body. They’re the building blocks of body tissue, after all, and they also provide the body with a source of energy.

So, what roles do they play exactly?

Proteins are mostly known for their ability to build and repair tissues (4). They can also contribute to the functioning of enzymes and hormones (5).

In short, they’re absolutely essential to our health and well being.

This also means they’re essential to the growth of healthy hair.

After all, if your protein levels are too low then the protein you consume will go to more essential functions. The scalp and hair will be neglected if chronic protein deficiency is present for too long.

And just as stated above, a protein deficiency can have serious health implications.

Aside from hair loss, a lack of protein in your diet can contribute to lack of muscle mass, low energy levels, and poor bone growth (R, R).

Five High-Protein Food Sources for Hair Growth

It’s obvious that you need to eat an appropriate amount of protein to maintain your health and wellness.

Let’s take a look at just a few of the highest protein food sources.


Eggs are probably one of the best high-protein food sources for your hair.


Eggs are relatively high in protein when compared to their size, with one large egg containing about six grams of protein.

But even more important is their high levels of the B-vitamin biotin.

Biotin is a nutrient that’s often marketed as a treatment for hair loss. The vitamin is responsible for an array of metabolic processes, and one of those is keratin synthesis (6).

When protein is consumed, it doesn’t just magically turn into keratin. It instead has to be metabolized by the body.

The biotin levels in eggs ensures that the protein you get is metabolized as it should be, and that’s one of the best things you can do to ensure healthy hair growth.


You likely know that meat is one of the greatest sources of protein available.

Protein is found in all animal meats, including beef, pork, and wild game. But if you want a meat source that’s high in protein and low in “bad” fats, then consider poultry.

Poultry is a term used to describe domestic fowl, such as chickens, turkeys, ducks, and geese. The meat of fowl tends to be low fat, but high in nutrients such as selenium, phosphorus, and protein.

And if you’re on a budget, you’ll be happy to know that poultry also tends to be quite a bit cheaper than many cuts of beef and pork.

Just how much protein does poultry contain?

The poultry with the highest level of protein is chicken breast with 31 grams of protein per 100 grams. The second is turkey breast with 22 grams of protein per 100 grams.

Of course, the amounts will vary slightly between different cuts (breast versus thigh, for example) and brands.


Fish is a popular protein served throughout the world.

You likely already know of its many beneficial components, include healthy fats and iron. But fish can also be an easy way to boost your daily protein intake.

Fish oils may reduce inflammation in the scalp

So, which fish contain the highest amounts of protein?

Tuna, halibut, and tilapia top the list.

For just three ounces, you can get 20 grams, 23 grams, and 22 grams of protein, respectively.

That’s not to say that those three fish are the only protein powerhouses, though. You can also include cod, pollock, and other such fish in your diet.

(Learn about the benefits of fish oil for hair growth here.)


Dairy, and milk in particular, is often given a bad reputation.

And if you’re sensitive to dairy or its various proteins, then you should avoid it to prevent inflammation and illness.

But the truth is that dairy does pack quite a bit of punch when it comes to proteins, fats, and other benefits nutrients.

One glass of milk, about 240 grams, has eight grams of protein and eight grams of fat.

It also contains a multitude of other healthy nutrients and minerals, including calcium, vitamin D, and magnesium.

The food group is also very easy to work into your diet.

Add it to your oats, eat a serving of cheese with crackers, or combine yogurt and berries for a quick (but nutritious!) treat.


Legumes are a plant family which includes beans, peas, lentils, peanuts, and pulses. They’re often used as a side dish in many cultures, though their health benefits have led to an increase in their popularity in recent years.

The foods in this group are often revered for their high fiber content. They can also provide a major source of proteins for vegetarians and omnivores alike.

On average, you can get seven grams of protein from just one serving of legumes.

Another member of the legume family which isn’t often classified as such is the soybean.

There are plenty of soy products, including tofu and tempeh, which you can include in your diet easily. They are filling, and they’re also packed with many nutrients and minerals.

Vegans, Vegetarians, and Protein Intake

If you’re a vegan or vegetarian, you may be wondering how you too can increase your protein intake.

It’s true that it can be difficult to meet your daily protein needs when animal products are taken out of the equation. But it’s certainly not impossible.

There are many plant-based sources of protein. Let’s take a look at a few.


As mentioned above, legumes are a group that include an array of seemingly unrelated foods. These include:

  • Beans
  • Peas
  • Peanuts
  • Soy products
  • Lentils

And also as mentioned above, these foods can add significant protein to your diet.

Just to give you a greater idea of how many food items there really are in this food group, here’s a breakdown of the above classified categories.

  • Beans: Kidney, navy, black, pinto, haricot bean, mung, adzuki, etc.
  • Peas: Garden, pigeon, chickpea, cowpea, snap, black-eyed, etc.
  • Soy: Edamame, miso, tempeh, tofu, textured soy protein, tamari, etc.
  • Lentils: Red (cobber, digger, nugget), brown (eston, verdina), and green (matilda, catellana, boomer).

You can add these foods to your meals and snacks, and they’ll help to fill in the gaps of your protein intake.

Nuts and Seeds

While technically two different food classifications, nuts and seeds are often grouped together due to their similar nutrient contents.

Almond oil provides nutrients to the hair follicles

Both of these food groups are known for their high levels of healthy fats. But did you know that many of them are also packed full of protein?

Almonds, for example, contain six grams of protein for every one-ounce serving. And chia seeds and hemp seeds aren’t far behind, with 4.7 grams and 5 grams per serving, respectively.


Your morning bowl of oatmeal may be providing you with more protein than you think.

Grains, including oats, spelt, quinoa, and amaranth, have surprising amounts of protein and other healthy nutrients.

Oats for example, contain six grams of protein in one-half cup.

But quiona and amaranth, though they’re considered “pseudocereals” within the grain classification, are the true superheroes of the bunch.

One serving of quinoa can provide as much as 9 grams of protein. The same can be said of amaranth.

The best part is that grains are easy to incorporate into your meals.

How Much Protein Does Your Body Need?

Just as with other nutrients, the protein needs of your body will vary by age, gender, and physical activity level.

The general guideline for calculating your daily protein needs is 0.8 g per kg of body weight (7).

This means that a person who weighs 68 kilograms (or about 150 pounds) needs 54.5 grams (68kg * 0.8) of protein per day.

The guideline is very general, though, and it doesn’t take into account the body’s changing needs.

For example, if you have a low body fat percentage then you’ll need a greater amount of protein in order to maintain your current muscle mass.

And as you get older, your protein needs will increase, too.

A 2004 research study, for example, recommends at least 1.0 g per kg of body weight for those who are seventy or older (8).

You may be asking yourself:

“What’s the right amount for me?”

The answer is, it depends.

You should aim to consume at least the minimum recommended amount of 0.8 grams per kilogram of body weight per day.

But you should also consult with your doctor on the matter.

Just keep in mind that the minimum recommended amount is just that – a recommendation. It doesn’t take into account any special needs that you may have, but it’s a good starting point.

Bodybuilding, High Protein Intake, and Hair Loss: Is There a Link?

If you search the internet for “bodybuilding and hair loss,” you’re bound to find dozens of articles on the topic.

And while an increase in hair loss may be present in those who bodybuild, the cause is unlikely to be too much protein consumption.

Creatine is common amongst bodybuilders and can trigger hair shedding

It’s true that you should limit your protein intake to no more than 2 grams per kilogram of body weight.

Why? Because too much of a good thing can cause health issues including heart disease, metabolic burden, and other health conditions (9).

But if you’re a bodybuilder who’s suffering from hair loss, the more likely causes include:

  • High testosterone levels
  • Increased scalp sensitivity to DHT
  • Increased cortisol levels

So if you’re within the recommended guidelines for protein intake and you’re still suffering from thinning and hair fall, then it’s best to speak with your doctor.

In Conclusion

There are many decisions we make today that can impact our scalp and hair health tomorrow. One of these is poor nutrition and, more specifically, low protein intake.

While low protein intake is unlikely to be the sole cause of your hair loss, it’s certainly a major contributing factor.

Do remember, though, that it’s also possible to have too much of a good thing.

Instead, as with all things, I recommend you find a healthy balance. The protein sources for hair growth mentioned above will give you a great start.

Do you have questions about the information provided above? Be sure to leave a comment below!