What Is Collagen — and Why Does Your Skin Lose It?

Every conversation about skin ageing eventually leads back to one word: collagen. It is the most abundant protein in the human body — making up around 75% of the skin's dry weight — and it is the primary reason skin looks either firm and lifted or loose and crepey. Understanding what collagen is, why you lose it, and how to stimulate it is the foundation of any intelligent anti-ageing strategy.

What collagen actually does

Collagen is a structural protein that forms a dense, interwoven network of fibres throughout the dermis — the middle layer of your skin. These fibres give skin its tensile strength, its ability to bounce back, and its overall firmness. Think of it as scaffolding: when it is intact and dense, everything above it looks supported and lifted. When it degrades, the surface starts to sag, crease, and lose definition.

When and why collagen declines

Collagen production peaks in your mid-20s and begins declining at approximately 1% per year from your late 20s onwards. By your 40s, the cumulative loss is significant enough to be visible — you'll notice a softening of the jawline, deeper lines, and skin that doesn't recover from expressions the way it once did. During menopause, collagen loss accelerates dramatically: studies show women can lose up to 30% of their dermal collagen in the first five years post-menopause.

Beyond natural ageing, collagen breakdown is accelerated by UV exposure (the primary external accelerant), smoking, chronic stress, poor sleep, processed sugar, and pollution. This is why two people of the same age can have dramatically different skin quality — lifestyle and sun history play an enormous role alongside genetics.

How professional treatments rebuild collagen

The most effective way to meaningfully rebuild collagen is through treatments that trigger a controlled healing response in the dermis. When the skin perceives a thermal or mechanical stimulus, it responds by producing new collagen as part of its repair process. At St James Aesthetics, this is the principle behind our most powerful skin treatments.

• HIFU: Delivers thermal energy to the deep dermal and SMAS layers, triggering significant collagen production and a genuine lifting effect over 3-6 months.

• RF Skin Tightening: Radiofrequency energy heats the dermis to stimulate collagen and elastin synthesis, progressively firming skin over a course of treatment.

• Infini RF Microneedling: Combines fine needles with radiofrequency for targeted collagen stimulation at specific skin depths — particularly effective for texture, firmness, and scarring.

To find out which collagen-stimulating treatment is right for your skin, book a consultation with our team at St James Aesthetics — Camberwell, Moonee Ponds, and Geelong clinics available.