Does Protein Help Hair Growth? An Evidence-Based Guide
Last reviewed on 25 July 2026. We review our treatment guides every six months to keep them accurate.
Hair is made almost entirely of protein, so it is a fair question whether eating more of it will make your hair grow. The honest answer is that enough protein is genuinely necessary for normal hair growth, but eating more than your body needs does not make hair grow any faster or thicker. This guide explains how much protein you actually need, the best sources, and what protein can and cannot do for your hair.
Hair loss has many possible causes, so it is worth understanding your own pattern before changing your diet. The NHS overview of hair loss is a reliable, regularly updated starting point, and it lists sudden weight loss and iron deficiency among the temporary causes worth ruling out. This article is general information rather than personal advice, so speak to your GP or a dietitian about your own situation.
Why your hair needs protein
Each strand of hair is built almost entirely from a structural protein called keratin, so a steady supply of dietary protein is needed to grow and maintain healthy hair (Trueb, 2021). When you eat protein-rich food, your body breaks it down into amino acids, the building blocks it then uses to build and repair its tissues, including hair (NHS). There are 20 amino acids in all; your body can make some of them, while the rest, known as essential amino acids, have to come from your diet, which is why variety matters.
If the body is short of protein for a long time, it tends to prioritise essential functions over hair growth, and hair can suffer as a result. In practice, though, most people in the UK eating a normal, varied diet already get more than enough protein for their hair.
Does eating more protein make hair grow faster?
No. Once you are eating enough protein to meet your body's needs, taking in more does not push your hair to grow faster or make it thicker. Reviews of diet and hair loss are clear that, in the absence of a genuine deficiency, it is unclear what extra protein or protein supplements can add (Guo and Katta, 2017). Hair grows at a fairly fixed rate set largely by your genetics, age and hormones, and no amount of extra protein overrides that. Meeting your normal daily requirement is the goal, not exceeding it.
How much protein do you need each day?
For adults who are not doing heavy training, the UK reference intake for protein is about 0.75 g per kilogram of body weight per day (British Dietetic Association). For someone weighing around 70 kg that works out at roughly 52 g of protein a day. Put another way, the NHS figure is on average about 56 g a day for men and 45 g a day for women (NHS).
The key point for hair is that your daily protein requirement for hair growth is simply your normal daily requirement. Your hair does not need a separate, higher protein target: once you are meeting your everyday needs through food, you are giving your hair everything it can use.
The best protein sources for healthy hair
There is no single "best" protein for hair. What helps is meeting your needs from a variety of good sources, so you take in the full range of amino acids along with the vitamins and minerals that also matter for hair, such as iron and zinc. The NHS Eatwell Guide groups the main options as beans, pulses, fish, eggs, meat and other proteins:
Lean meat and poultry: beef, lamb, pork, chicken and turkey are rich sources of protein along with iron, zinc and B vitamins. The NHS suggests choosing lean cuts and eating less red and processed meat such as bacon, ham and sausages.
Fish, including oily fish: aim for at least two portions of fish a week, one of which is oily, such as salmon, sardines or mackerel, which also provide omega-3 fatty acids.
Eggs: a convenient complete protein that also supplies several vitamins and minerals.
Dairy: milk, yoghurt and cheese provide protein along with calcium and vitamin B12; lower-fat options keep saturated fat down.
Beans, peas and lentils: naturally low in fat and high in fibre as well as protein, and a good alternative to meat.
Nuts and seeds: a useful source of protein and healthy fats; unsalted nuts make a good snack in moderation.
Soya foods: tofu, tempeh and other soya products are complete plant proteins that suit vegetarian and vegan diets.
Getting enough protein on a vegetarian or vegan diet
You can meet your protein needs without meat or fish. The NHS guidance on vegetarian and vegan diets recommends eating a variety of protein sources, such as beans, lentils, chickpeas, eggs, dairy, tofu, other soya products and mycoprotein, so that together they supply the right mixture of amino acids. Combining different plant proteins across the day is a simple way to cover this. If you are unsure whether your diet is balanced, a dietitian can help.
Protein deficiency and hair loss
A genuine lack of protein can cause hair loss. Severe protein malnutrition, as seen in conditions such as kwashiorkor, is well recognised to cause hair thinning and shedding (Guo and Katta, 2017). You do not have to be severely malnourished for diet to matter, either: very restrictive, low-protein diets and crash diets can reduce the supply of raw material to the hair follicle and trigger a diffuse shedding called telogen effluvium, as noted in the clinical literature on telogen effluvium. The NHS likewise lists sudden weight loss among the temporary causes of hair loss.
This kind of shedding is usually temporary. Once protein intake and overall nutrition are corrected, hair growth generally recovers over several months. If you are following a very low-calorie or low-carbohydrate diet, are noticing diffuse thinning, or suspect a broader nutritional deficiency, it is worth reviewing your diet with your GP or a dietitian, who may arrange blood tests.
Can too much protein cause hair loss?
This is a common worry, but excess dietary protein itself is not an established cause of hair loss. The clear link in the research runs the other way, from too little protein rather than too much. Where high-protein regimes are blamed for shedding, the trigger is usually the rapid weight loss or the low intake of other nutrients that can go with a restrictive diet, not the protein as such. It is a good idea not to overdo protein for other reasons, since the NHS notes that consistently very high intakes may not suit everyone, particularly people with existing kidney problems (NHS), but the honest position on hair specifically is that surplus protein has no proven role in causing hair loss.
Protein shakes, whey and pea protein
Protein shakes and powders, including whey and pea protein, are simply a convenient way to add protein if you are struggling to get enough from food. They are not a hair treatment. There is no good evidence that a protein shake grows hair, and no reason to expect one to help if you are already meeting your daily needs (Guo and Katta, 2017). The same applies to pea protein specifically: it is a perfectly good plant protein, but it will only make a difference to your hair if it is correcting a genuine shortfall in your diet. Whole foods remain the best foundation, with shakes as a top-up rather than a replacement.
If you are interested in the wider question of nutritional supplements and hair, our guide to collagen and hair growth looks at another popular option in the same evidence-led way.
The bottom line
Protein is essential for healthy hair because hair is built from it, and a genuine lack of protein can cause reversible shedding. But protein is not a growth booster: once you are meeting your normal daily requirement of around 0.75 g per kilogram of body weight from a varied diet, more protein, protein shakes or specific proteins such as pea protein will not make your hair grow faster or thicker. If your hair loss is bothering you, the most useful step is a proper assessment by your GP or a dietitian, who can check for any underlying cause.
Frequently asked questions
How much protein do I need for hair growth?
Your hair does not need a special amount of protein beyond your everyday requirement. For most adults the UK guideline is about 0.75 g of protein per kilogram of body weight a day, roughly 56 g for an average man and 45 g for an average woman. Meeting that through a varied diet gives your hair all the protein it can use; eating more than you need does not grow hair faster.
Does a lack of protein cause hair loss?
Yes. A genuine shortage of protein, for example from severe malnutrition, an eating disorder or a very restrictive crash diet, can push hair follicles into a resting, shedding phase called telogen effluvium and cause diffuse thinning. It is usually reversible once protein intake and overall nutrition are restored, which typically takes several months.
Can too much protein cause hair loss?
Excess protein on its own is not an established cause of hair loss. When high-protein diets are linked to shedding, it is usually the rapid weight loss or the low intake of other nutrients that goes with a restrictive diet that is responsible, rather than the protein itself. There is no proven mechanism by which simply eating plenty of protein causes hair to fall out.
Do protein shakes help hair growth?
Only if they are correcting a genuine protein shortfall in your diet. Protein shakes are a convenient way to top up your intake, but there is no good evidence that they grow hair in someone who is already eating enough protein. They are best viewed as a food supplement, not a hair treatment.
Does pea protein help hair growth?
Pea protein is a good plant-based source of protein and suits vegan diets, but it is not a hair growth product. Like any protein, it will only benefit your hair if it is helping you meet a daily requirement you were otherwise falling short of. On its own it does not make hair grow faster or thicker.
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