Which type of protein is best for hair growth? A comprehensive nutritional guide

October 5, 2025 •

3 min read

Hair is composed of over 90% protein, specifically keratin, highlighting protein's fundamental role in its growth and structure. This guide explores which type of protein is best for hair growth by examining key types, their benefits, and how to incorporate them into your diet for optimal hair health.

Quick Summary

Protein is crucial for healthy hair, providing amino acids to build keratin and support follicle function. Ensuring a balanced intake from diverse sources, including whole foods, supplements, and topical treatments, is key to preventing hair loss and promoting strand strength.

Key Points

Hair is Built of Keratin: The vast majority of your hair is made of the protein keratin, so a consistent supply of amino acids is essential for its production.
Protein Deficiency Causes Hair Loss: An inadequate intake of protein can cause hair follicles to prematurely enter a shedding phase, leading to thinning and hair loss.
Variety is Key: Both animal proteins (eggs, fish) and well-planned plant-based diets (soy, legumes, quinoa) provide the full range of essential amino acids needed for healthy hair.
Hydrolyzed Collagen Boosts Elasticity: Oral supplements of hydrolyzed collagen can provide key amino acids for keratin and have been shown to improve hair elasticity and thickness.
Topical Proteins Repair Damage: Hydrolyzed protein treatments applied to hair can strengthen and moisturize the hair shaft by filling in gaps in the cuticle.
Whey Protein Considerations: While a fast-absorbing source of amino acids, whey protein may influence hormones like DHT in genetically predisposed individuals, potentially affecting hair loss.
Combine with Other Nutrients: Protein intake is most effective when paired with other crucial nutrients like iron, zinc, and biotin, which also support follicle health.

The Fundamental Role of Protein in Hair Growth

Protein is critical for healthy hair growth. Hair follicles need a constant supply of amino acids, the components of protein, to create keratin, the main protein in hair. Adequate protein intake is essential because the body prioritizes vital functions over hair growth when protein is scarce. This can cause hair follicles to enter a resting phase prematurely, leading to increased shedding known as telogen effluvium. Consuming a diet rich in complete proteins, which provide all nine essential amino acids, directly aids the production of strong hair.

Animal vs. Plant Protein for Hair Health

Both animal and plant proteins support hair growth, each with unique nutritional benefits.

Animal Proteins

Animal proteins are complete proteins, offering all essential amino acids for efficient hair production. {Link: Little Extra https://littleextralove.com/blog/hair-care/pea-protein-hair-benefits}

Plant-Based Proteins

Many plant sources offer amino acids and other hair-benefiting nutrients. Pea sprout extract has shown potential in stimulating hair growth.

Key Proteins and Their Specific Benefits

Different proteins impact hair health through consumption and topical application.

Keratin

Keratin is the primary protein of hair. While the body makes it naturally, topical hydrolyzed keratin can repair damaged hair by strengthening the cuticle and reducing frizz. Oral keratin supplements have less evidence for direct hair growth benefits.

Collagen

Collagen is vital for the scalp's dermis layer, where hair follicles are situated. It supplies amino acids like proline and glycine for keratin production. Hydrolyzed collagen peptides may prolong the hair growth phase.

Whey Protein

Whey is a fast-absorbing dairy protein supplement rich in amino acids beneficial for cell health. However, in individuals with a genetic predisposition to balding, some forms of whey may increase testosterone and its conversion to DHT, a hormone that can contribute to hair loss.

Hydrolyzed Proteins

Hair products often contain hydrolyzed proteins from sources like wheat, rice, and silk. Broken into smaller molecules, they can penetrate the hair shaft, improving strength, moisture, and texture, especially for damaged hair.

Comparison of Protein Types for Hair Growth


Protein Type	Primary Source	Mechanism for Hair	Key Nutrients	Best For
Animal Protein	Meat, eggs, dairy, fish	Provides complete amino acid profile for keratin synthesis. Iron aids oxygen delivery.	Essential amino acids, iron, zinc, biotin, Vitamin B5	All-around support for strong, healthy hair
Plant Protein	Legumes, soy, nuts, seeds, quinoa	Delivers amino acids, vitamins, minerals. Can provide complete profile when varied.	Isoflavones (soy), L-arginine (pea), antioxidants, biotin	Vegans/vegetarians; those seeking hypoallergenic options
Collagen	Bone broth, fish, supplements	Supplies specific amino acids (proline, glycine) for keratin and dermis health. Supports follicle anchoring.	Proline, Glycine, Hydroxyproline	Improving hair elasticity, thickness, and hydration; reducing loss
Whey Protein	Dairy, supplements	Rich in BCAAs and fast-absorbing. Can support overall protein intake.	BCAAs (leucine, valine, isoleucine), cysteine, methionine	Fitness enthusiasts; requires caution for those with balding predisposition
Hydrolyzed Proteins	Wheat, rice, silk, keratin	Penetrates hair shaft to repair cuticle damage, strengthen strands, and add moisture.	Amino acids, peptides	Topical use for damaged, dry, or frizzy hair

How to Optimize Protein for Hair Growth

A balanced approach is best for supporting hair growth.

Prioritize a Balanced Diet: Consume a variety of high-quality complete proteins from whole foods for a broad spectrum of amino acids and co-factors.
Consider Supplements Wisely: Targeted supplements like collagen peptides or plant-based protein powders may help if your diet is restrictive or you have a suspected deficiency. Consult a healthcare provider before starting supplements.
Don't Overlook Topical Treatments: Hydrolyzed protein products can improve hair's cosmetic health, but balance them with moisturizing treatments to avoid brittleness.
Pair with Hair-Healthy Nutrients: Ensure sufficient intake of iron, zinc, and biotin, which work with protein for follicle health. Vitamin C aids iron absorption.
Practice Patience: Visible hair growth improvements take time, typically three to six months after dietary changes.

Conclusion: Finding the Best Protein for Hair Growth

So, which type of protein is best for hair growth? The most effective strategy involves a consistent and sufficient intake of diverse, high-quality proteins through a healthy diet. While animal proteins offer a complete amino acid profile, well-planned plant-based diets are also effective. For specific benefits, hydrolyzed collagen or topical keratin can be helpful. {Link: Little Extra https://littleextralove.com/blog/hair-care/pea-protein-hair-benefits}

Frequently Asked Questions

Yes, protein powders can help if you struggle to meet your daily protein needs through diet alone. However, those with a predisposition to hair loss should consider the potential hormonal effects of whey protein and may opt for a plant-based powder instead.

Keratin is the protein that hair is made of, while collagen provides the building blocks and strengthens the scalp environment to support keratin production. Neither is definitively 'better'; they serve different functions. Oral collagen supports from the inside, while topical keratin primarily repairs external damage.

Visible results from dietary or supplement changes typically take three to six months. Hair growth is a slow process, and consistency is more important than immediate results.

While unlikely from diet alone, excessive use of topical protein treatments can lead to a protein-moisture imbalance, causing hair to become brittle and prone to breakage. It is important to balance protein treatments with moisturizing products.

For most people, a balanced diet of whole foods provides sufficient protein for healthy hair. Supplements are typically only necessary if dietary intake is consistently low, a specific deficiency is identified, or dietary restrictions (e.g., veganism) limit options.

Yes, plant-based proteins are effective, especially when combining different sources to achieve a complete amino acid profile. Sources like soy and pea protein offer robust amino acid content and additional benefits.

Hydrolyzed proteins have been broken down into smaller molecules, allowing them to penetrate the hair cuticle. They temporarily fill in damaged areas, strengthening the hair shaft, improving texture, and retaining moisture.