What collagen actually does (and why so many people take it)
Collagen supplements have gone from niche to mainstream over the last decade, which naturally raises the question: are they worth it? This is an honest introduction to what collagen actually is, what the evidence base supports, and where marine collagen fits into a broader wellness routine. Short answer: it isn't a miracle protein, but for skin, joints, hair and nails it has real evidence — and understanding what it does and doesn't do makes it easier to decide whether it's for you.
What is collagen?
Collagen is the most abundant protein in the human body, accounting for roughly a third of total protein content. It provides structure and elasticity to skin, bones, tendons, ligaments, cartilage, and connective tissue. Twenty-eight different types of collagen have been identified, but Type I is by far the most abundant — it makes up much of skin, bone, and tendon.
Your body produces its own collagen using amino acid building blocks (particularly glycine, proline, hydroxyproline, and lysine) from the protein you eat. Various other nutrients — vitamin C especially — are used by the body in the process of collagen synthesis.
Why collagen production changes with age
From around age 25, the body's natural collagen production begins to decline at roughly 1% per year. This decline accelerates significantly around menopause — research by Brincat and colleagues found that up to 30% of skin collagen can be lost in the first five years after menopause, driven by falling estrogen (estrogen supports collagen production, which is why the change is so noticeable during this life stage).
Over time, the effects show up as:
- Fine lines, less skin firmness, more dryness — the classic signs of aging skin, driven substantially by collagen changes
- Stiffer or less resilient joints — collagen is a key component of cartilage, tendons, and ligaments
- Changes in hair thickness and nail strength — connective tissue support affects these too
- Reduced bone density — bone's organic matrix is largely collagen; this is particularly relevant for postmenopausal women
Where the collagen supplementation evidence is strongest
Skin
The strongest evidence base for oral collagen supplementation is for skin outcomes. Clinical research consistently shows improvements in skin elasticity, hydration, and the appearance of fine lines with daily supplementation of hydrolyzed marine collagen peptides at around 10g per day, over 8-12 weeks. Consistency matters more than anything else.
Joints
Emerging evidence supports collagen supplementation for joint comfort and function, particularly when combined with an exercise program. Studies use doses in the 5-15g per day range, over 12+ weeks. Note: this is about joint comfort broadly — collagen isn't a treatment for specific joint conditions like gout or rheumatoid arthritis. Our honest guide on supplements for gout covers the specific case of gout.
Hair and nails
Emerging evidence suggests marine collagen may support hair condition and nail strength. The evidence base here is less developed than for skin, but many people notice nail changes within the first few weeks of consistent supplementation.
Bone density
Emerging evidence, particularly in postmenopausal women alongside adequate vitamin D and calcium intake. Bone's organic matrix is largely collagen, so this makes biological sense — and the early clinical research is encouraging while not yet definitive.
Why marine collagen specifically?
Collagen supplements can come from several sources: bovine (cow), porcine (pig), or marine (fish). Marine collagen has some specific advantages worth understanding:
- Higher bioavailability — marine collagen has been shown to be up to 1.5x more bioavailable than bovine collagen
- Predominantly Type I — the type most relevant for skin and connective tissue support
- Suitable for a wider range of religious and dietary preferences — bovine collagen isn't suitable for everyone; marine works for most (though not those with fish allergies)
Vitamin C is genuinely important alongside collagen because your body uses it in collagen synthesis (specifically for the hydroxylation of proline and lysine residues). B vitamins support normal energy metabolism, which is a related but separate part of the picture. Kollo's formula combines marine collagen with vitamin C and B vitamins (B1, B5, B6, B12) for that reason.
Featured Product
Premium Liquid Marine Collagen
10,000mg of clinically studied marine collagen daily — for visibly smoother, firmer, more hydrated skin in as little as 28 days.
Shop Liquid Collagen →What collagen doesn't do — being honest
Foundations for healthy aging beyond collagen
Collagen is one supportive habit, not a stand-alone solution. The foundations that actually matter for how you feel and look as you age:
- Daily SPF — the single highest-impact skincare habit for anyone. UV damage is the biggest driver of visible skin aging
- Sleep — cellular repair happens overnight; consistent sleep matters more than most supplements
- Balanced nutrition — enough protein, colorful vegetables, healthy fats, and adequate calorie intake
- Regular movement — mix aerobic and resistance training; both support joint health, bone density, mood, and body composition
- Not smoking — smoking damages collagen and skin directly
- Watching alcohol intake — read our honest guide to alcohol and collagen for the picture
- Managing stress — chronic stress affects everything from sleep to skin to immune function
- Regular check-ins with your doctor — especially past 40, for blood pressure, cholesterol, blood glucose, thyroid, and other markers that matter
A word on Kollo
Kollo Premium Liquid Marine Collagen delivers 10,000mg of Naticol® marine collagen peptides per daily sachet, alongside vitamin C, a B vitamin complex (B1, B5, B6, B12) and l-lysine. It comes as a liquid sachet — tear, drink, done — which makes daily consistency easier than pills or powders for many people. Every batch is Informed Choice certified, independently tested for over 250 prohibited and potentially harmful substances. Not suitable for anyone with a fish allergy.
Frequently Asked Questions
What does collagen actually do for the body?
Collagen is a structural protein that provides framework and elasticity to skin, bones, tendons, ligaments, cartilage, and connective tissue. Oral collagen supplementation provides the amino acid building blocks the body uses in its own collagen production. The strongest clinical evidence is for skin outcomes — elasticity, hydration, and the appearance of fine lines — with emerging evidence for joints, bone density, hair, and nails.
When should I start taking collagen?
Natural collagen production begins to decline from around age 25, so any point from your twenties onward is reasonable if you're focused on skin, hair, nails, or joint support. There's no specific "must start by" age. Whether it makes sense for you depends on your individual goals and situation.
How much collagen should I take?
The clinical research on skin outcomes consistently uses around 10g (10,000mg) of hydrolyzed collagen peptides per day. Kollo delivers this dose per daily sachet. Many capsule supplements contain a fraction of this, which is why lower-dose products often don't show visible results.
How long before I see results?
Most people who notice changes report them over 8-12 weeks of consistent daily use — this matches the clinical research on skin outcomes. Some notice earlier changes in skin feel or nails within the first few weeks. Consistency matters more than perfect timing.
Is marine collagen better than bovine collagen?
Marine collagen has been shown to be up to 1.5x more bioavailable than bovine collagen and has a strong research base for skin outcomes specifically. Both work; marine is often preferred because of the bioavailability and because it's suitable for a wider range of religious and dietary preferences.
More honest guides on collagen and specific concerns: alcohol and collagen, collagen and fatigue, collagen and menopause-related teeth problems, and supplements for gout.
Kollo Health was co-founded by Jenni Falconer — TV presenter, Smooth Radio breakfast host, ten-time London Marathon runner and host of the RunPod podcast. Read her story and why she created Kollo.
