Originally written by ZRT Laboratory author. Reproduced with permission. Last reviewed: May 2026.
Wrinkling, thinning, and sagging skin are among the most visible signs of ageing — but they are not simply the result of time passing. Behind these changes lies a complex interplay of hormonal shifts, chronic stress, nutritional status, and lifestyle factors that collectively determine how quickly the skin ages and how well it can repair itself.
At the centre of this process is collagen: the primary structural protein responsible for firm, smooth, resilient skin. Understanding what collagen is, why we lose it, and what we can do to protect it is one of the most powerful things we can do for long-term skin health.
What Is Collagen and Why Does It Matter for Skin?
Collagen is the most abundant protein in the human body, making up approximately 30% of total protein content. It is the main structural component of connective tissue throughout the body — including skin, cartilage, tendons, ligaments, bone, and intervertebral discs.
In the skin specifically, collagen is found within the extracellular matrix of the dermis — the connective tissue layer beneath the outer skin surface. Here, collagen fibres provide structural integrity, giving the skin its strength, firmness, and elasticity. Healthy collagen levels translate to skin that feels full and firm, bounces back when stretched, and resists the formation of fine lines and wrinkles.
Alongside collagen, the extracellular matrix contains a gel-like substance rich in glycosaminoglycans (GAGs) — protein-polysaccharide molecules including hyaluronic acid that act as lubricants and shock absorbers, retaining moisture and giving tissues their characteristic plumpness. The combination of collagen fibres and GAG-rich gel is what gives youthful skin its characteristic texture and resilience.
The consequences of collagen loss extend beyond the skin. Stiff joints, degenerating tendons, disc problems, and other musculoskeletal complaints are all related to the same underlying process of collagen depletion that manifests visibly in the skin.
Why Do We Lose Collagen as We Age?
Collagen production begins to decline from the mid-twenties onwards, at a rate of approximately 1% per year. In women, this decline accelerates sharply at menopause when oestrogen levels fall. In men, declining testosterone and DHEA levels from the late thirties onwards similarly contribute to reduced collagen synthesis and accelerated skin ageing — a process sometimes called andropause.
Several factors accelerate this natural decline — what might be called the primary “collagen killers”:
- Declining hormone levels — oestrogen in women, testosterone and DHEA in men
- Chronic stress and elevated cortisol
- Poor nutrition — insufficient protein, vitamin C, vitamin A, and antioxidants
- Dehydration
- Smoking, which directly degrades collagen fibres
- UV sun damage, which breaks down collagen and impairs its synthesis
- Elevated blood sugar and insulin resistance, which drive glycation
- Chronic inflammation and oxidative stress
Conversely, the factors known to support collagen synthesis include a nutrient-dense diet rich in protein, omega-3 fats, colourful vegetables and fruits; balanced hormone levels; regular exercise; adequate hydration; and healthy blood glucose regulation.
The Role of Hormones in Skin and Collagen Health
Oestrogen and Women’s Skin
Oestrogen is one of the most powerful regulators of skin health in women. It supports collagen synthesis, increases skin thickness and elasticity, and maintains moisture by stimulating the production of hyaluronic acid and other GAGs within the extracellular matrix. By acting on both the structural (collagen) and hydration (GAG) components of the dermis simultaneously, oestrogen is a potent protector against wrinkle formation.
The decline of oestrogen at perimenopause and menopause is therefore one of the most significant drivers of accelerated skin ageing in women. Studies suggest women lose up to 30% of skin collagen in the first five years after menopause. Research has shown that oestrogen therapy — whether applied topically or used systemically — can increase collagen production and restore measurable improvements in skin thickness, elasticity, and moisture.
If you are a woman experiencing skin changes alongside other symptoms of hormonal imbalance — such as fatigue, mood changes, sleep disturbance, or irregular periods — our Advanced Female Wellness Test provides a comprehensive assessment of oestrogen, progesterone, testosterone, DHEA, cortisol, and thyroid markers, with a specialist doctor’s report to guide next steps.
Testosterone, DHEA, and Men’s Skin
Skin ageing is not exclusively a women’s concern. Men also experience significant hormone-driven collagen loss as testosterone and DHEA decline with age. Testosterone supports collagen synthesis in the skin, and low testosterone in men is associated with thinner, drier, less resilient skin alongside the more commonly recognised symptoms of fatigue, low libido, and reduced muscle mass.
DHEA — a precursor hormone produced by the adrenal glands — also plays a role in skin health in both men and women, supporting sebum production, skin thickness, and collagen density. DHEA levels peak in the mid-twenties and decline steadily thereafter.
If you are a man noticing accelerated skin ageing alongside reduced energy, mood changes, or declining physical performance, our Advanced Male Wellness Test measures testosterone, DHEA, cortisol, thyroid markers, and toxic elements — with a specialist doctor’s report included to help you understand what is driving your symptoms.
How Stress and Cortisol Accelerate Skin Ageing
Chronic stress is one of the most underappreciated drivers of premature skin ageing in both men and women. When the body is under sustained stress, the adrenal glands produce elevated levels of cortisol — the primary stress hormone. While cortisol is essential in short bursts, chronically elevated levels have a directly destructive effect on collagen.
Excess cortisol down-regulates collagen synthesis, leading to thinner, weaker connective tissue throughout the body — including the skin. The result is accelerated wrinkling, reduced skin resilience, and impaired wound healing. Stress management may therefore be one of the most important — and most overlooked — interventions for long-term skin health.
Beyond its direct effect on collagen, elevated cortisol contributes to skin ageing through several indirect mechanisms:
- Increased sebum production, which can trigger or worsen acne
- Sugar cravings and elevated blood glucose, which drive the formation of advanced glycation end-products (AGEs) that stiffen and degrade collagen fibres
- Increased inflammatory cytokines, which impair wound healing, skin regeneration, and barrier function
- Elevated free radical load, which damages skin cells and collagen through oxidative stress
Assessing your cortisol pattern — including the cortisol awakening response, which reflects how your adrenal system activates at the start of each day — can reveal whether chronic stress is contributing to your skin concerns. Our Cortisol Awakening Response Test uses LCMS-validated saliva analysis to measure your cortisol pattern across the morning, providing a clinically meaningful picture of adrenal function and stress load — relevant for both men and women.
Other Factors That Contribute to Wrinkles and Skin Ageing
Glycation and Advanced Glycation End-Products (AGEs)
When blood sugar levels are chronically elevated — whether from a high-sugar diet, insulin resistance, or type 2 diabetes — glucose molecules bind to collagen and elastin fibres in a process called glycation. The resulting AGEs make collagen fibres rigid, brittle, and less able to support the skin structure. Reducing simple sugar intake and maintaining healthy blood glucose levels is therefore directly relevant to skin health and collagen preservation.
Oxidative Stress and Free Radicals
Free radicals — unstable molecules generated by UV exposure, pollution, smoking, stress, and poor diet — damage collagen fibres and impair the skin’s ability to repair itself. Antioxidants, both dietary (vitamin C, vitamin E, polyphenols, carotenoids) and topical (vitamin C serums, retinoids), help neutralise free radicals and protect collagen from oxidative damage.
Chronic Inflammation
Low-grade systemic inflammation — driven by poor diet, gut dysbiosis, chronic stress, and environmental toxins — activates enzymes called matrix metalloproteinases (MMPs) that break down collagen. An anti-inflammatory diet rich in omega-3 fatty acids, colourful vegetables, and polyphenols helps suppress this inflammatory collagen degradation.
Hyaluronic Acid and GAG Depletion
Alongside collagen, the loss of hyaluronic acid and other GAGs from the extracellular matrix contributes significantly to the loss of skin volume, moisture, and plumpness associated with ageing. Oestrogen is a key regulator of GAG production in women, while testosterone and DHEA play similar supportive roles in men — making hormonal decline a dual threat to both structural and hydration components of the skin in both sexes.
Practical Steps to Protect and Restore Skin Collagen
Nutrition
- Eat adequate protein — collagen synthesis requires sufficient amino acids, particularly glycine, proline, and hydroxyproline
- Prioritise vitamin C, which is essential for collagen cross-linking and synthesis
- Include vitamin A from food sources or consider topical retinoids, which stimulate collagen production
- Eat a wide variety of colourful vegetables and fruits for antioxidants, minerals, and phytonutrients
- Include omega-3 rich foods (oily fish, flaxseed, walnuts) to reduce inflammation
- Minimise simple sugars and refined carbohydrates to reduce glycation
- Stay well hydrated
Hormone Balance
- Women: assess oestrogen, progesterone, testosterone, and DHEA, particularly if perimenopausal or postmenopausal
- Men: assess testosterone, DHEA, and cortisol if experiencing skin changes alongside fatigue, mood shifts, or reduced physical performance
- Discuss hormone replacement or optimisation with a knowledgeable clinician if deficiency is confirmed
Stress and Cortisol Management
- Test your cortisol pattern to understand whether chronic stress is actively breaking down your collagen
- Implement regular stress reduction: mindfulness, yoga, adequate sleep, and time in nature all reduce cortisol
- Prioritise sleep — growth hormone, which stimulates collagen synthesis, is primarily released during deep sleep
For a comprehensive view of adrenal function across the full day, our Adrenal Function Saliva Test Kit measures cortisol at four time points throughout the day using LCMS analysis — suitable for both men and women — revealing your complete diurnal cortisol pattern and identifying whether adrenal dysregulation may be contributing to accelerated skin ageing.
Lifestyle
- Exercise regularly — physical activity improves circulation, supports detoxification, and stimulates collagen synthesis
- Protect skin from UV exposure with broad-spectrum SPF daily
- Stop smoking — smoking directly degrades collagen and impairs skin repair
- Monitor and manage blood glucose levels, particularly if you have insulin resistance or diabetes
Frequently Asked Questions
At what age does collagen production start to decline?
Collagen production begins to decline gradually from the mid-twenties, at approximately 1% per year. This decline accelerates significantly at menopause in women due to falling oestrogen, and progressively in men as testosterone and DHEA decline from the late thirties onwards.
Do men lose collagen as they age?
Yes. While the dramatic oestrogen-driven collagen loss at menopause is well documented in women, men also experience significant hormone-related collagen decline as testosterone and DHEA fall with age. Men’s skin tends to be thicker than women’s due to higher testosterone levels, but this advantage diminishes as hormone levels decline. Assessing testosterone and DHEA alongside cortisol can identify hormonal drivers of skin ageing in men.
Can hormone replacement therapy improve skin collagen?
Yes. In women, oestrogen therapy has been shown to increase collagen production, improve skin thickness and elasticity, and enhance moisture retention. In men, testosterone optimisation can similarly support collagen synthesis and skin quality. The timing of hormone therapy initiation and the method of delivery both influence outcomes.
How does stress cause wrinkles?
Chronic stress elevates cortisol, which directly suppresses collagen synthesis and accelerates collagen breakdown. Elevated cortisol also drives sugar cravings (increasing glycation), raises inflammatory markers (impairing skin repair), and increases free radical production (causing oxidative damage to collagen fibres). These mechanisms apply equally to men and women.
What is the best diet for collagen production?
A diet that supports collagen production is rich in protein, vitamin C, vitamin A, antioxidants, and omega-3 fatty acids, while minimising simple sugars to reduce glycation. Adequate hydration supports the GAG-rich gel that works alongside collagen in the skin.
Can collagen supplements improve skin?
Evidence for oral collagen peptide supplements is growing, with several trials showing improvements in skin elasticity, hydration, and wrinkle depth. However, supplements work best as part of a broader approach that addresses the underlying hormonal, nutritional, and lifestyle factors driving collagen loss.
Originally written by ZRT Laboratory author. Reproduced with permission. Last reviewed: May 2026.