How Collagen Supplements Support What Your Body Loses After 25

Collagen supplements are increasingly popular and for good reason. From your mid-twenties, your body begins losing the protein that holds everything together: the scaffolding beneath your skin, the cushioning in your joints, and the structural support around your hair follicles. By the time you reach your forties, you may have lost a significant portion of your peak collagen density and the effects show up in ways most people recognise, but rarely connect to a single cause.

In this guide we cover the science of collagen decline, what accelerates it, and, crucially, what you can actually do about it. Including why, for hair health specifically, the combination of collagen supplementation and targeted red light therapy may offer something no other approach can match.

What Is Collagen and Why Does Your Body Need It?

Collagen is the most abundant protein in the human body, accounting for roughly 30% of your total protein content. Think of it as structural cable: tough, fibrous strands that give your tissues their form, strength, and flexibility. It is found in:

• Skin: providing firmness, elasticity, and moisture retention
• Joints and cartilage: acting as cushioning and shock absorption
• Bones and tendons: lending tensile strength and resistance to breakage
• Hair follicles and scalp: anchoring follicles in the dermis and supporting the hair growth cycle
• Blood vessels and organs: maintaining structural integrity throughout the body

There are at least 28 types of collagen, but Types I, II, and III account for the vast majority in the body. Type I — the most abundant — is the one most relevant to skin and hair. It forms the dense network of fibres in the dermis that gives skin its resilience, and it lines the scalp tissue that houses your hair follicles.

Collagen production is carried out by specialised cells called fibroblasts. When you’re young, fibroblasts work efficiently, producing fresh collagen faster than existing fibres break down. With age, that balance shifts — and the consequences become increasingly difficult to ignore.

At What Age Does Collagen Production Start to Decline?

Collagen production typically begins to slow from the mid-twenties, declining by around 1% each year. By your forties the cumulative loss becomes visible in skin firmness, joint comfort and hair thickness.

That 1% figure sounds modest. But it compounds. By your late forties, you may have lost 20–25% of your peak collagen density. By your sixties, that number can rise significantly higher — particularly for women, who experience an accelerated period of loss around menopause.

Here is how collagen changes tend to manifest across the decades:

Decade	What’s Happening	What You May Notice
20s	Production at or near peak. Fibroblasts working efficiently.	Skin is firm and elastic. Joints recover quickly. Hair is at its thickest.
30s	Gradual slowdown begins. First signs of imbalance between production and breakdown.	Fine lines around eyes and mouth. Joints may feel it after intense exercise. Some early hair thinning.
40s	Decline accelerates. Fibroblast activity diminishes. Hormonal changes (especially in women) compound the effect.	Skin loses elasticity and may begin to sag. Joint stiffness more frequent. Hair diameter and density may reduce.
50s+	Significant reduction in collagen synthesis. Post-menopausal women can lose up to 30% of skin collagen in the first five years after menopause.	Thinner, drier skin. Deeper wrinkles. Potential hair thinning and slower regrowth. Bone density concerns emerge.

Why Collagen Levels Drop: The Biological Causes

Several mechanisms work simultaneously to slow collagen production as we age.

Fibroblast ageing

Fibroblasts, the cells that synthesise collagen, become less active over time. They produce collagen at a slower rate, and the collagen they do produce tends to be lower in quality, with fibres that are less organised and more prone to fragmentation.

Hormonal changes

Oestrogen plays a direct role in supporting collagen synthesis. As oestrogen levels decline gradually from the mid-thirties, then more sharply around perimenopause and menopause, collagen production drops correspondingly. Research suggests women can lose around 30% of their skin collagen in the five years following menopause. This hormonal pathway is one reason women tend to notice the effects of collagen loss more acutely than men.

Amino acid availability

Collagen is built from specific amino acids primarily glycine, proline, and hydroxyproline. As we age, the body’s ability to synthesise and absorb these building blocks can decline, creating a nutritional bottleneck even before lifestyle factors enter the picture.

Lifestyle Factors That Accelerate Collagen Loss

The rate of collagen decline is not purely biological — several everyday habits can significantly speed up the process:

• UV exposure: Ultraviolet rays penetrate the dermis and degrade collagen fibres directly, a process known as photoaging. Daily SPF is arguably the single most effective external intervention for slowing collagen loss.
• Smoking: Nicotine constricts blood vessels and reduces oxygen delivery to skin tissue. It also generates free radicals that actively break down collagen and elastin.
• High sugar intake: Sugar binds to collagen fibres in a process called glycation, making them rigid and brittle. Diets high in refined carbohydrates accelerate this structural damage.
• Poor sleep: The majority of cellular repair, including collagen synthesis, takes place during deep sleep. Consistently poor sleep deprives the body of its main repair window.
• Chronic stress: Elevated cortisol — the primary stress hormone — directly impairs collagen synthesis and accelerates breakdown of existing fibres.
• Excessive alcohol: Alcohol disrupts the absorption of nutrients critical to collagen production, including vitamin C and zinc, and generates inflammatory compounds that degrade collagen.

How Collagen Decline Affects Hair Growth and Thickness

Most information about collagen focus on skin and joints. But the connection between collagen decline and hair thinning is equally significant and far less discussed.

Here is the mechanism: your hair follicles sit within the dermis, embedded in a collagen-rich matrix. Type I and Type III collagen fibres form a structural sheath around each follicle, anchoring it securely in the scalp and providing the mechanical environment the follicle needs to complete its growth cycle. As collagen declines and the dermal matrix thins, follicles can become less stable — reducing the quality and diameter of the hair shaft they produce.

~32%: Increase in hair growth observed in a 12-week study of hydrolysed collagen supplementation (NCBI, 2023)

Collagen, keratin, and your hair

Hair itself is made primarily of keratin, a protein built from many of the same amino acids as collagen — particularly glycine and proline. When collagen levels decline and amino acid availability drops, the body may struggle to produce sufficient keratin, contributing to hair that is finer, more brittle, or grows more slowly.

Collagen supplementation – particularly hydrolysed collagen peptides, which break collagen down into easily absorbed amino acids – can help restore this nutritional substrate, giving follicles the raw materials they need to produce healthy, structurally sound hair.

What the research shows

A 2023 peer-reviewed clinical trial published on the NCBI database studied subjects with androgenetic alopecia and telogen effluvium over 12 weeks. Those receiving hydrolysed marine collagen supplementation showed a 32.4% increase in hair growth compared to insignificant change in the placebo group. A separate 12-week trial found improvements in scalp condition, hair quality, and hydration following oral collagen intake. While the evidence base is still developing, these findings support the mechanistic case for collagen’s role in hair health.

How to Increase Collagen Production: Diet, Lifestyle and Supplements

While it’s true that time only moves in one direction, the encouraging reality is that collagen decline may be inevitable, but it’s not entirely un-addressable. There are evidence-based strategies that can support, protect, and even stimulate collagen production.

1. Nutrition and Supplementation

Collagen is built from amino acids, so a protein-rich diet matters. Beyond that, several nutrients play a supporting role:

• Vitamin C: Essential for collagen synthesis. Without it, fibroblasts cannot produce collagen properly.
• Hydrolyzed collagen peptides: Emerging research supports the idea that oral collagen supplements may help stimulate the body’s own collagen production, though the evidence is still developing.
• Zinc and copper: Both are essential cofactors in collagen cross-linking, the process that makes collagen structurally strong.

2. Topical Retinoids

Retinoids (vitamin A derivatives) are among the most studied topical treatments for aging skin. They work by binding to receptors in the skin that signal fibroblasts to produce more collagen and speed up cell turnover. Consistent use over months shows measurable improvements in skin texture and firmness.

3. Sun Protection — Every Single Day

This one is non-negotiable. Daily broad-spectrum SPF 30 or higher is one of the most effective tools for preserving existing collagen. UV damage accumulates silently even on cloudy days, even through windows.

4. Professional Treatments

Treatments like microneedling, RF (radiofrequency) therapy, and certain laser procedures work by creating controlled micro-injury to the skin, triggering the body’s wound-healing response and stimulating new collagen formation. These can produce noticeable results but require professional administration and recovery time.

5. Red and Infrared Light Therapy

One of the more exciting developments in at-home skincare is the increasing accessibility of non-thermal light therapy — a technology that was once confined to clinical settings.

Low-Level Light Therapy (LLLT) using visible red light (typically wavelengths in the 630–660nm range) and infrared light (usually 810–950nm) works at the cellular level. LLLT works by radiating nonthermal light onto the skin, where it’s absorbed and stimulates mitochondria — the energy-producing structures in cells — to increase production of ATP (adenosine triphosphate). In layman’s terms, it triggers processes in cells that make them more efficient and productive. This boost in cellular energy has been shown in numerous studies to:

• Stimulate fibroblast activity, increasing collagen and elastin production
• Reduce inflammation in the dermis
• Improve circulation, which helps deliver oxygen and nutrients to skin cells
• Support the skin’s natural repair processes

Unlike UV, thermal or ablative phototherapy (which damages collagen), LLLT’s red and near-infrared wavelengths are bio-stimulating — they support the skin’s natural processes rather than harming them. This makes consistent, at-home use a realistic option for anyone looking to address collagen decline proactively.

Understanding why collagen declines is only useful if it leads to action. Here is a practical breakdown of evidence-backed approaches:

Dietary foundations

The body cannot produce collagen without the right nutritional building blocks. Key dietary priorities include:

• Vitamin C: An essential cofactor in collagen synthesis. Without adequate vitamin C, the body cannot properly form collagen triple-helix structures. Sources include citrus, kiwi, bell peppers, and leafy greens.
• Protein-rich foods: Eggs, fish, chicken, and legumes provide glycine, proline, and other amino acids required for collagen production.
• Zinc and copper: Both minerals are involved in collagen cross-linking and fibroblast activity. Found in nuts, seeds, shellfish, and wholegrains.
• Bone broth: One of the few dietary sources of intact collagen peptides. Regular consumption may provide some directly bioavailable collagen precursors.

Lifestyle habits that protect existing collagen

• Daily SPF: The most evidence-supported topical intervention for preventing UV-driven collagen degradation.
• Consistent sleep: Aim for 7–9 hours. Growth hormone — released during deep sleep — directly stimulates collagen production.
• Reduce sugar and smoking: Both glycation and nicotine-driven oxidative stress cause structural damage to existing collagen fibres.
• Stress management: Sustained cortisol elevation is a significant but often overlooked driver of collagen breakdown.

Collagen supplements: what to look for

Collagen supplements — particularly hydrolysed collagen peptides — are the most direct way to supply the amino acids the body needs to rebuild collagen. Hydrolysed means the collagen has been broken down into shorter peptide chains that are readily absorbed through the gut wall, making them significantly more bioavailable than intact collagen.

When choosing collagen supplements, look for:

• Type I (and/or Type III) collagen: Most relevant to skin, hair, and scalp health.
• Hydrolysed / peptide form: Ensures bioavailability — unhydrolysed collagen is poorly absorbed.
• Vitamin C included or taken alongside: Critical for converting amino acids into usable collagen in the body.
• Third-party tested: Ensures purity and accurate dosage labelling.

Can Red Light Therapy Boost Collagen Production?

This is where Growell offers something genuinely different and it is backed by a growing body of peer-reviewed research.

Red light therapy (also called photobiomodulation, or PBM) uses specific wavelengths of light – typically 630–660 nm in the red spectrum – to penetrate the skin and directly stimulate fibroblast activity. The mechanism is well understood: red light is absorbed by mitochondria in dermal cells, triggering increased ATP synthesis, which in turn accelerates collagen and elastin production.

630–660nm: The red light wavelength range clinically shown to stimulate fibroblast collagen synthesis in the dermis

A 2025 PubMed study found that red light rapidly increased dermal thickness and stimulated collagen synthesis in fibroblasts in ageing skin tissue. Research published in the Journal of the American Academy of Dermatology demonstrated that low-level red and infrared light increased gene expression of collagen, elastin, and hyaluronic acid in human fibroblasts. Multiple randomised controlled trials have reported measurable increases in intradermal collagen density following red light therapy protocols.

When applied to the scalp, red light therapy targets the very tissue where collagen decline has the most direct impact on hair follicle health, the dermal matrix surrounding each follicle. By stimulating fibroblast activity in this zone, it supports the structural environment that follicles need to function optimally.

The Growell red light therapy cap is designed specifically for scalp delivery, ensuring consistent, targeted exposure across the full follicular zone  without the limitations of handheld devices or clinic-based treatments.

Best Collagen Supplements for Hair Loss: What to Look For

The collagen supplement market is substantial and growing, which makes choosing well more important, and more confusing. Here is a practical framework for evaluating collagen supplements specifically for hair health:

• Prioritise Type I and Type III collagen: Type I is the most abundant in the scalp dermis and directly supports follicle anchoring. Type III forms alongside Type I in skin tissue and helps maintain the matrix structure.
• Choose hydrolysed collagen peptides: Only hydrolysed forms are meaningfully absorbed through the digestive tract. Look for ‘collagen peptides’ or ‘hydrolysed collagen’ on the label.
• Check the cofactors: Vitamin C is essential for collagen synthesis — supplements that include it (or that recommend taking it alongside) are better formulated for practical results. Biotin and hyaluronic acid are useful additions for hair and skin health.
• Consider marine vs bovine: Marine collagen (from fish) is predominantly Type I and has a smaller peptide size, which some research suggests improves absorption. Bovine collagen provides both Type I and Type III. Both have clinical support.
• Dosage: Most clinical studies showing positive results for hair and skin use 2.5–10g of hydrolysed collagen per day. Check that the supplement provides a clinically relevant dose, not a token amount buried in a proprietary blend.
• Women over 40: Given the accelerated collagen loss around perimenopause, women in this group may benefit from starting collagen supplementation earlier and sustaining it consistently. Look for formulations that include vitamin C and consider pairing with a red light therapy protocol for a compounded effect.

 

Ready to take action against collagen decline?

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This article is for educational purposes only and is not intended as medical advice. Always consult a qualified healthcare professional regarding any skin or health concerns.