The short answer
Yes, hair needs protein: it’s made almost entirely of a protein called keratin. Not eating enough protein can cause shedding and weak, brittle hair, though it’s uncommon unless your diet is very restricted. Crash diets, eating disorders, weight-loss injections and fast weight loss are the usual causes. Protein shampoos and masks change how hair feels, not how it grows.
Can lack of protein cause hair loss?
Yes. When protein is short, the body saves it for essential jobs, and hair growth is cut back. More hairs move into the resting phase and shed two to three months later, from all over the scalp: a type of shedding called telogen effluvium.
- More hair than usual on your brush and in the shower
- Hair that feels thinner, weaker or more brittle
- Weak nails, low energy and feeling cold, if your overall diet is low
How much protein do you need?
Most adults need about 0.75 g of protein per kilogram of body weight a day, which is around 45 g for a 60 kg woman and 55 g for a 75 kg man. Having some protein at every meal is an easy way to get enough.
Good sources of protein
- Eggs, fish, meat and poultry
- Milk, yoghurt and cheese
- Beans, lentils, chickpeas, tofu and tempeh
- Nuts, seeds and wholegrains
If you eat a vegan or vegetarian diet, eat a variety of plant proteins through the day, and check your iron, B12 and zinc too, as they are vitamins and minerals hair needs. Protein matters even more if you’re losing weight fast, for example on weight-loss injections.
Do protein hair products help?
They can make damaged hair feel smoother and stronger for a while, but they don’t feed the follicle or fix a poor diet. Used too often, they can leave hair stiff and more likely to snap and form split ends.
If something isn’t right with your hair or scalp, a consultation is where I take your history, examine your hair and scalp closely and give you a written plan.
Questions
Does protein help hair growth?
Only if you’re not getting enough. Eating more protein than you need won’t make hair grow faster.
Can lack of protein cause hair loss?
Yes. A diet very low in protein can trigger shedding a few months later, and make hair weaker and more brittle.
Do I need protein supplements for my hair?
Most people get enough protein from food. Supplements only help if your diet falls short.
Will my hair grow back if I eat more protein?
If low protein was the cause, shedding usually settles a few months after your diet improves, and regrowth follows.