Collagen supplements have gone from niche to mainstream in the UK remarkably quickly. Walk into any health food shop and you'll find a shelf full of powders, capsules, drinks and gummies all claiming to do something meaningful for your skin, joints or hair.
Most of the marketing is well ahead of the evidence. This guide tries to sit the other side of that — covering what collagen actually is, what the research currently supports, what to look for in a supplement, and what to be sceptical of.
We make a marine collagen product, so read the final section knowing that. Everything before it applies to any collagen supplement.
What is collagen?
Collagen is the most abundant protein in the human body. It makes up roughly 30% of total body protein and is found throughout connective tissue — in skin, tendons, ligaments, cartilage, bones and blood vessels.
Structurally, collagen works like scaffolding. In skin, collagen fibres form a dense network in the dermis — the middle layer — that gives skin its structure, firmness and elasticity. In joints, collagen forms the cartilage that cushions bones. In tendons and ligaments, it provides tensile strength.
There are at least 28 types of collagen, but types I, II and III account for the vast majority in the human body. Type I is the most abundant and is found in skin, bone, tendons and the gut wall. Type II is concentrated in cartilage. Type III is found alongside type I in skin and blood vessels.
Most collagen supplements are type I. Marine collagen is almost exclusively type I.
What happens to collagen as you age?
Collagen production declines with age — this is well established.
The peak of collagen production is generally in your mid-to-late 20s. After that, production decreases by approximately 1-1.5% per year. By 40, many people have lost a meaningful proportion of their skin's structural collagen. By 60, the reduction is significant enough to be measurable in skin biopsies.
Several factors accelerate collagen loss beyond normal ageing:
- UV exposure — one of the most significant environmental factors
- Smoking — directly disrupts collagen synthesis
- High sugar intake — glycation damages collagen fibres
- Vitamin C deficiency — Vitamin C is required for normal collagen synthesis
The visible consequences — skin that looks thinner, less firm, or more lined — are largely a reflection of this structural change in the dermis. Joint discomfort in older age also partly reflects changes in cartilage collagen.
None of this means collagen supplements will reverse these changes. What it explains is why there is genuine biological interest in whether they can support collagen synthesis.
How do collagen supplements work?
When you eat collagen — from food or a supplement — your digestive system breaks it down into amino acids and small peptides. It doesn't arrive at your skin intact. This is a point worth understanding because it's where a lot of supplement marketing misleads people.
The relevant question is whether the amino acids and peptides from hydrolysed collagen specifically support collagen synthesis in the body, and whether they do so better than amino acids from other protein sources.
The honest answer is: the evidence suggests they might, but it is not settled science.
What hydrolysed collagen peptides are
Hydrolysed collagen — also called collagen hydrolysate or collagen peptides — has been broken down by enzymes into smaller peptide chains. These are small enough to be absorbed through the gut wall more efficiently than whole collagen protein.
Low molecular weight peptides
The absorption question partly comes down to molecular weight. Standard collagen peptides have a molecular weight of roughly 3,000-5,000 Daltons. Low molecular weight peptides — sometimes called nano peptides — are smaller still, typically under 2,000 Daltons.
Smaller particles pass through the gut lining more readily. This is the basis for "nano" or "low molecular weight" claims you see on some products, including ours.
What happens after absorption
The most studied mechanism is that certain collagen-derived peptides — particularly dipeptides like hydroxyproline-proline — may act as signals that stimulate fibroblasts (the cells in skin that produce collagen) to increase collagen synthesis. This is studied primarily in cell culture and some human trials.
The evidence from randomised controlled trials is modest but real. A 2019 systematic review in the Journal of Drugs in Dermatology looked at 11 studies on oral collagen supplementation and skin outcomes. Most reported improvements in skin hydration, elasticity or density. The studies were generally small, and industry-funded, which requires the usual caution. But the effect sizes were consistent enough that researchers consider it a plausible mechanism worth further study.
This is different from saying "collagen supplements work." It means the biological mechanism is plausible, some human evidence exists, and more rigorous research is ongoing.
Marine collagen vs bovine collagen
Most collagen supplements are either marine (from fish) or bovine (from cows). There are also chicken, porcine and vegan alternatives — though vegan collagen supplements do not contain collagen itself, they contain nutrients that support the body's own collagen synthesis.
Marine collagen
Marine collagen is derived from fish — typically the skin, scales or bones. It is almost entirely type I collagen, which is the type most relevant to skin. It has a lower molecular weight than bovine collagen, which theoretically supports better absorption.
Marine collagen is the preferred option for people who avoid beef for dietary, ethical or religious reasons.
Bovine collagen
Bovine collagen is derived from cow hides. It contains both type I and type III collagen. It is generally cheaper to produce than marine collagen and widely used in supplements and food products.
Which is better?
Direct comparison trials are limited. Most researchers consider the choice less important than the dose, the hydrolysis quality and whether Vitamin C is present — since Vitamin C is required for normal collagen formation.
The role of Vitamin C and Zinc
Two nutrients are particularly relevant to collagen — and both have authorised health claims in the UK.
Vitamin C
Vitamin C is required for the hydroxylation of proline and lysine, two amino acids essential to collagen structure. Without adequate Vitamin C, normal collagen synthesis cannot occur. This is why severe Vitamin C deficiency (scurvy) causes skin and connective tissue breakdown.
The authorised UK health claim: Vitamin C contributes to normal collagen formation for the normal function of skin.
Taking a collagen supplement without adequate Vitamin C is therefore suboptimal. This is why we include liposomal Vitamin C in our Nano Marine Collagen formula.
Zinc
Zinc plays a role in collagen synthesis and is also involved in skin, hair and nail maintenance.
The authorised UK health claim: Zinc contributes to the maintenance of normal skin, hair and nails.
What to look for in a marine collagen supplement
1. Source and type
Confirm the collagen is marine-derived and the type is stated. Most marine collagen is type I. If a product does not state the source or type, treat this as a red flag.
2. Hydrolysed peptides, not whole collagen
The supplement should specify it is hydrolysed collagen or collagen peptides. Whole, non-hydrolysed collagen is not meaningfully absorbed by the gut.
3. Molecular weight
Low molecular weight peptides (under 2,000 Daltons) are generally considered to absorb better. Some products state this, some don't. Products that do have typically invested more in their formulation.
4. Vitamin C
Given its requirement for normal collagen synthesis, a product that includes Vitamin C — or one you take alongside adequate Vitamin C — is worth prioritising.
5. Third-party testing
A certificate of analysis from an independent laboratory confirms the product contains what it says it does. Ask the brand for theirs if it is not published.
6. No unsupported claims
In the UK, there are no authorised health claims for collagen itself. If a product claims to "reduce wrinkles," "reverse ageing," or "rebuild joints," it is making a claim that is not permitted under UK advertising rules. Treat this as a signal about how honest the brand is prepared to be elsewhere.
7. Allergen information
Marine collagen contains fish. This must be declared. If you have a fish allergy, marine collagen is not suitable.
What the research does not yet support
This is the section most collagen brands skip. We don't.
- Joint repair: There is some evidence from small trials that collagen peptides may support cartilage in people with osteoarthritis. The evidence is not strong enough to make a confident recommendation. If you have joint problems, speak to a physiotherapist or GP.
- Hair and nail growth: Some small studies suggest an association. The evidence is early and inconsistent.
- Muscle mass: Some research combines collagen peptides with resistance training. The specific contribution of collagen to muscle outcomes is hard to isolate.
- Gut health: Some practitioners suggest collagen supports the gut lining. Human clinical trial evidence for this is very limited.
- Anti-ageing: There is no licensed claim for collagen reversing or slowing ageing. Any product making this claim is in breach of UK advertising rules.
None of this means collagen is ineffective. It means the evidence is still being built, and honest marketing acknowledges that.
How to take marine collagen
Dose
Most studies that have shown effects on skin outcomes have used doses between 1,000mg and 10,000mg per day. Our Nano Marine Collagen provides 1,600mg per daily serving (4 capsules).
Timing
There is no strong evidence that timing matters significantly. Taking it consistently is more important than taking it at a specific time. With food is generally recommended for tolerability.
Duration
Most studies run for 8-12 weeks. Collagen synthesis is a slow biological process. Expecting visible results within a week is unrealistic — if a supplement claims rapid visible improvement, be sceptical.
Consistency
As with most food supplements, consistent daily intake over months is the appropriate way to approach collagen supplementation. It is not an acute supplement.
About Ivvion Nano Marine Collagen
Held against the criteria above:
- Source: Deep ocean marine collagen — type I hydrolysed peptides
- Molecular weight: Low molecular weight — designed for better absorption
- Formula: 1,600mg marine collagen peptides, 80mg sodium hyaluronate (hyaluronic acid), 156mg liposomal Vitamin C, 56mg bamboo silica, 20mg phytoceramides from rice bran, 4.8mg zinc
- Why we included Vitamin C: Because collagen without Vitamin C is incomplete. Vitamin C contributes to normal collagen formation for the normal function of skin — an authorised UK health claim.
- Why we included Zinc: Zinc contributes to the maintenance of normal skin, hair and nails — authorised UK claim.
- Manufacturing: UK-made in a BRCGS A-grade, GMP-certified, ISO 9001 facility
- Testing: Third-party tested every batch. Certificate of analysis available on request.
- Allergens: Contains fish. Not vegan. Not suitable for those with fish allergies.
- Claims: We make only the two authorised claims above. We do not claim to reduce wrinkles, reverse ageing, or repair joints.
Frequently asked questions
Is marine collagen vegan? No. Marine collagen is derived from fish. It is not vegan. If you are looking for a vegan alternative, you would need nutrients that support the body's own collagen synthesis — primarily Vitamin C and zinc — rather than collagen itself.
Can I take collagen if I have a fish allergy? No. Marine collagen contains fish and must be avoided by anyone with a fish allergy. Bovine collagen would be an alternative, though you should confirm ingredients with any specific brand.
How long before I notice anything? Most trials that report any outcomes run for at least 8 weeks. Some people notice changes in skin hydration earlier; many notice nothing specific. Set expectations accordingly.
Is collagen powder better than capsules? Not necessarily. What matters more is the quality of the hydrolysis, the molecular weight, the dose, and whether Vitamin C is present. The delivery format is a secondary consideration.
Can I take collagen with other supplements? Yes in most cases. Collagen pairs well with Vitamin C (required for collagen formation) and zinc. There are no well-documented negative interactions with common supplements, but if you take prescription medication, check with your GP or pharmacist.
What is hyaluronic acid and why is it in your collagen product? Hyaluronic acid (sodium hyaluronate) is a molecule naturally found in skin and joints that helps retain water. It is included in our formula as a complementary ingredient to the collagen peptides.
Food supplement. Not a medicine. Does not diagnose, treat, cure or prevent any disease. Do not exceed the recommended daily dose. Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle. If you are pregnant, breastfeeding, taking medication, or have a medical condition, please consult your doctor before starting. Contains fish.