Updated: November 2025

Your complete, evidence-based guide to understanding keratin supplementation, the clinical science behind it, and why it actually works for hair health

Your hair is falling out faster than it's growing back. Your nails are brittle. Your skin looks tired and dull. And you're wondering: is there actually something that can help, or are these supplements just expensive placebos?

The answer lies in understanding the science. Keratin isn't just marketing hype. It's a structural protein that makes up 90% of your hair, and when your body doesn't have enough of it, your hair suffers. But here's the crucial part: not all keratin supplements work the same way. Understanding how they work, what makes them effective, and which ones are actually backed by science is essential before you invest in them.

Let's break down the real science behind keratin supplementation.

Understanding Keratin: The Foundation of Your Hair

What Is Keratin?

Keratin is a fibrous, structural protein that forms the foundation of your hair, skin, and nails. It's not just one component among many, it's the primary building block.

Your hair is approximately 90% keratin. Your nails are primarily keratin. The outer layer of your skin contains keratin. When you have adequate keratin, these tissues are strong, resilient, and protected. When keratin levels drop, everything weakens.

Why Keratin Matters

Keratin provides:

• Strength: Makes hair resistant to breakage and stretching

• Elasticity: Allows hair to bend without snapping

• Protection: Forms a protective barrier against environmental damage

• Structure: Creates the architecture that holds your hair together

• Water retention: Helps hair stay hydrated and glossy

Without adequate keratin, your hair becomes:

• Brittle and prone to breaking

• Dull and lifeless

• Prone to split ends and damage

• Slow to grow

• Difficult to style

• Vulnerable to environmental stress

This isn't vanity. This is biology.

What Causes Keratin Depletion?

Before understanding how keratin supplements work, understand why your keratin levels drop in the first place.

Natural Causes:

Aging: Your body produces less keratin naturally after age 30, declining approximately 1% per year

Hormonal Changes: Pregnancy, menopause, and hormonal shifts reduce keratin production

Stress: Chronic stress elevates cortisol, which disrupts keratin production and pushes hair into the shedding phase

Nutritional Deficiency: Insufficient protein, iron, zinc, biotin, or other key nutrients impairs keratin production

Environmental and Lifestyle Causes:

Rapid Weight Loss: Significant weight loss (surgery or extreme dieting) creates nutritional stress that depletes keratin

Chemical Damage: Colour treatments, relaxers, and perms break down keratin structure

Heat Damage: Blow dryers, straighteners, and curling irons damage keratin bonds

Chlorine Exposure: Pool or shower chlorine oxidises and damages keratin structure

Poor Hair Care: Harsh shampoos, rough brushing, and tight hairstyles all damage keratin

Environmental Pollution: UV rays, pollution, and toxins damage keratin and deplete protective amino acids

When you understand what depletes your keratin, you understand why supplementation can be so powerful.

How Keratin Supplementation Works: The Science

The Bioavailability Problem

Here's where most keratin supplements fail: standard keratin has essentially zero bioavailability.

Your digestive system can't break down or absorb intact keratin protein. It's too large and structurally complex. This is why generic, cheap keratin supplements don't work, no matter how much keratin they claim to contain.

This is where Functional Keratin™ is fundamentally different.

How Functional Keratin™ Actually Works

Functional Keratin™ uses patented technology that breaks keratin into bioavailable forms your body can actually absorb and use.

The process:

1. Extraction: Keratin is carefully extracted from New Zealand sheep wool using patented methods that preserve protein integrity

2. Processing: The keratin is broken down (hydrolysed) into free amino acids and small peptides that your digestive system recognizes

3. Absorption: Your body absorbs these amino acids through your intestinal wall into the bloodstream

4. Utilization: Your cells recognize these amino acids as keratin building blocks and use them to rebuild hair structure, strengthen nails, and repair skin

5. Results: Within 60-90 days, your body has enough raw material to significantly improve hair strength, reduce shedding, and support growth

The Key Metric: Bioavailability

Functional Keratin™ achieves 91% bioavailability to human keratin, meaning it's structurally almost identical to the keratin already in your hair.

This isn't theoretical. This is measured, tested, and proven through rigorous clinical research.

The Clinical Evidence: What Research Actually Shows

The Gold Standard Study

A double-blind, placebo-controlled study of 65 women aged 45-60 over 60 days found remarkable results with Functional Keratin™:

Hair Loss Reduction:

• 43.1% reduction in hair loss after 60 days (measured by hair pull test)

• This wasn't marginal improvement, this was clinically significant hair loss reduction

Hair Structure Improvements:

• 17.61% increase in hair cortex integrity (the actual strength of hair strands)

• Hair became demonstrably stronger and more resilient

Hair Anchoring:

• Improved follicle anchoring, meaning hair stayed more firmly rooted in the scalp

• Directly translated to less shedding and better hair retention

Skin Health:

• 10.1% increase in gross skin elasticity after 60 days

• 12.5% reduction in trans epidermal water loss after 30 days (better hydration)

• Visible reduction in fine lines and improvement in skin appearance

Mechanism of Action:
The research showed that Functional Keratin™ works by stimulating collagen IV expression, which acts as the anchoring protein at the hair root and the structural protein at the dermal-epidermal junction in skin.

This isn't just "people said their hair felt better." This is measurable, objective improvement in hair structure, skin elasticity, and hair loss reduction.

Key Ingredients in High-Quality Keratin Pills and Their Roles

Functional Keratin™ (The Star Ingredient)

The primary active ingredient providing 91% bio-identical keratin for hair structure rebuilding

Role: Provides the exact protein building blocks your hair needs to repair damage and strengthen from within

Biotin (Vitamin B7)

A B vitamin that supports keratin production pathways in your body

Role: Activates your body's natural ability to produce more keratin while the supplemented Functional Keratin™ provides the structural support

Vitamin C

An antioxidant that supports collagen synthesis and protects cells from free radical damage

Role: Protects your hair and skin from oxidative stress while supporting the connective tissue that holds hair follicles in place

Vitamin E

A fat-soluble antioxidant that protects cell membranes from damage

Role: Shields hair from environmental damage (UV, pollution, heat) and supports scalp health

Zinc

A mineral essential for hair tissue growth, repair, and immune function

Role: Supports hair follicle health, reduces inflammation, and prevents hair loss from deficiency

Iron

Critical for oxygen transport to hair follicles

Role: Ensures hair follicles receive adequate oxygen and nutrients to maintain the growth phase and prevent shedding

Folic Acid

A B vitamin that supports cell division and DNA synthesis

Role: Helps hair follicles divide and grow new hair cells, improving blood flow to the scalp

Why This Combination Works

These ingredients don't work in isolation. Together, they address multiple mechanisms:

• Functional Keratin™ provides the structure

• Biotin supports production pathways

• Vitamin C and E protect from damage

• Zinc supports follicle health

• Iron delivers oxygen

• Folic acid supports cell division

The result? Comprehensive hair health support from multiple angles simultaneously.

The Benefits of Keratin Supplementation: What the Research Shows

Supports Hair Growth and Reduces Shedding

Keratin pills contain the building blocks your body needs to maintain the growth phase of hair and strengthen follicles, reducing shedding by up to 43%

Improves Hair Strength and Elasticity

Keratin is the primary structural protein in hair. Supplementing with bioavailable keratin directly increases hair strength, measured at 17.61% improvement in cortex integrity in clinical studies

Promotes Faster, Healthier Hair Growth

With adequate keratin and supporting nutrients, your body can produce new hair that's stronger, thicker, and more resilient from the start

Nourishes the Scalp

The vitamins and minerals in quality keratin supplements (especially B vitamins and zinc) support scalp health, reducing irritation and flaking

Adds Shine and Lustre

Properly hydrated, keratin-rich hair reflects light better and looks noticeably healthier and more vibrant

Protects From Damage

Antioxidants (vitamins C and E) and protective amino acids shield your hair from environmental stressors, heat damage, and chemical damage

Supports Skin and Nails Too

Because keratin is the building block for skin and nails as well, you'll likely notice improved skin elasticity (10.1% in studies) and stronger nails alongside hair benefits

Non-Invasive and Convenient

Unlike hair treatments, transplants, or prescription medications, keratin supplementation is simply a daily pill that fits easily into any routine

Works From the Inside Out

Rather than trying to patch up damage topically, keratin pills address the root cause by providing your body with the actual building blocks it needs to rebuild

How to Maximize Results: Best Practices

Consistency Is Everything

Results appear within 60-90 days with consistent daily use, but improvement continues over 6 months. Missing days delays results. Daily consistency is non-negotiable.

Pair With Supportive Nutrition

Keratin supplementation works best when combined with:

• Adequate protein intake (0.8-1g per kg body weight daily)

• Iron-rich foods if you're deficient

• Plenty of water for hydration

• Antioxidant-rich vegetables and fruits

• Healthy fats for absorption

Supplementation fills gaps, but a balanced diet provides the foundation.

Manage Stress

Stress elevates cortisol, which disrupts keratin production and pushes hair into the shedding phase. Exercise, sleep, and stress management amplify keratin supplementation benefits.

Use Gentle Hair Care

While Functional Keratin™ works from within to rebuild your hair structure, protecting your hair externally (avoiding harsh shampoos, heat, tight hairstyles) prevents new damage.

Be Patient and Persistent

Hair grows slowly, about half an inch per month. You'll notice hair strength improvements within 60-90 days, but visible length improvements take longer. Patience and consistency are the keys.

Safety and Precautions: What You Should Know

General Safety Profile

Quality keratin supplements like Functional Keratin™ are well-tolerated with no significant adverse effects in clinical trials. They're derived from natural sources and your body recognizes them as nutrients.

Important Precautions:

Consult Your Healthcare Provider:
Before starting any supplement, especially if you have existing medical conditions, take medications, or are pregnant or breastfeeding

Check for Allergies:
Review the ingredient list carefully. While allergies to keratin supplements are rare, some people may react to specific ingredients

Medication Interactions:
Some supplements may interact with blood thinners or other medications. Discuss with your doctor if you're on any medications

Pregnancy and Breastfeeding:
Research on safety during pregnancy and breastfeeding is limited. Consult your healthcare provider before taking during these periods

Quality Matters:
Choose brands that have been third-party tested for purity, potency, and safety. Not all keratin supplements are created equal

Follow Recommended Dosage:
Never take more than the recommended amount. More doesn't mean faster results, it just increases the risk of side effects

Keratin Pills vs. Other Hair Loss Solutions

The Bottom Line: Why Keratin Pills Actually Work

Keratin pills work because they address the actual problem: insufficient keratin structure in your hair.

When your hair lacks keratin, no topical treatment can fix it because the damage is structural. You can't coat your way to healthier hair if the hair itself is damaged or weak.

But when you provide your body with bioavailable Functional Keratin™, something remarkable happens:

Your body recognises these amino acids as the building blocks it needs, and it gets to work rebuilding and strengthening your hair from the inside out.

Within 60 days, you see measurable improvements. By 90 days, the results are undeniable. And by 6 months, many people barely recognise their own hair, it's so much stronger, thicker, and healthier.

This isn't magic. It's biochemistry. It's your body finally having the raw materials it needs to do what it's designed to do: maintain strong, healthy hair.

The question isn't whether keratin pills work. The question is whether you're willing to be consistent for 60-90 days to get the results you deserve.

References and Further Reading

• Effect of keraGEN IV Keratin Oral Supplementation - Lincoln Agritech - Double-blind clinical study showing 43.1% hair loss reduction

• keraGEN IV Clinical Study - Keraplast - Comprehensive peer-reviewed research on hair structure improvement

• The Effects of Oral Keratin Supplementation - PMC - Research on bioavailability and hair health

• Hair Loss: Causes and Prevention - American Academy of Dermatology - Professional guidelines on understanding hair loss

• Why New Zealand Keratin Is Superior - Kiri10 - Deep dive into Functional Keratin™ sourcing and extraction

• KiriGlow Keratin Supplement - Kiri10 - Our clinically-formulated keratin supplement

• Hair Growth and Nutrition - Harvard Health - Research on nutritional support for hair health

• Understanding Hair Structure and Keratin - PMC - Scientific overview of keratin's role in hair