Marine Collagen Supplements: A Guide to Collagen for Skin
Collagen is the main structural protein in skin, and the body makes less of it with age. Marine collagen supplements provide collagen peptides from fish, and are often combined with hyaluronic acid and antioxidants for skin support. This guide explains how collagen supplements work, what to look for on the label, and who should be careful.
Medically reviewed by Dr. Reina Punj, MBBS, PG Diploma in Endocrinology (University of South Wales), Lead Physician, Excelgenics Clinical Panel.
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What is marine collagen?
Marine collagen comes from fish skin or scales and is mainly type I collagen, the type found most in human skin. In supplements it is usually hydrolysed, which means it has been broken down into smaller pieces called collagen peptides that are easier to digest. Marine collagen is not suitable for vegetarians, vegans or people with a fish allergy.
Marine collagen vs other collagen
| Type | Source | Notes |
|---|---|---|
| Marine collagen | Fish skin or scales | Mainly type I collagen; no beef or pork |
| Bovine collagen | Cattle hide or bone | Types I and III; widely used in powders |
| "Vegan collagen" | Plant ingredients | Contains no collagen; provides nutrients the body uses to make its own, such as vitamin C and amino acids |
What to look for in a collagen supplement for skin
| What to check | Why it matters | Radia (per 2-capsule daily serving) |
|---|---|---|
| Collagen type and form | Hydrolysed peptides are the form used in most research. | Hydrolysed marine collagen peptides (type I & III) |
| Collagen amount | Powders usually deliver several grams per serving; capsules deliver less but add other ingredients. | 500 mg |
| Hyaluronic acid | Holds water in the skin; often paired with collagen for hydration. | 100 mg low-molecular-weight hyaluronic acid |
| Vitamin C | Contributes to normal collagen formation. | 65 mg |
| Antioxidants | Vitamin E, vitamin C and zinc contribute to the protection of cells from oxidative stress. Radia also contains grape seed extract, CoQ10, lycopene and astaxanthin. | Grape seed extract (100 mg), CoQ10 (60 mg), lycopene (10 mg), vitamin E (10 mg), astaxanthin (4 mg); also zinc (5 mg) |
| Format | Capsules are portable and tasteless; powders mix into drinks. | Capsules |
Marine collagen powder vs tablets and capsules
Powders are the easiest way to take larger amounts of collagen in one go. Tablets and capsules are more convenient, with no taste or mixing, and suit formulas that combine collagen with other skin nutrients. Choose the format you will take every day, since consistency matters most.
What does the research say?
Several clinical trials have reported improvements in skin hydration and elasticity with hydrolysed collagen peptides over 8–12 weeks. Most of these trials used 2.5–10 g of collagen peptides a day; capsule products such as Radia contain less collagen and combine it with other ingredients. The evidence is still debated: a 2025 review in The American Journal of Medicine found that the benefits were seen mainly in industry-funded and lower-quality studies, while independent, higher-quality trials found no significant effect. The authors concluded there is currently no clinical evidence to support collagen supplements for preventing or treating skin ageing. Collagen supplements are best seen as one part of skin care, alongside sun protection, a balanced diet, sleep and not smoking.
How to take a collagen supplement
- Dose: follow the label. For Radia, that is 2 capsules a day after a meal.
- Be consistent: skin renews itself slowly, so take it daily for several weeks before judging results.
- Time of day: there is no proven best time. Pick a time you will remember, such as after breakfast.
- Protect your skin: daily sunscreen does more to protect collagen than any supplement.
Side effects of collagen supplements
Collagen supplements are generally well tolerated. Some people notice mild stomach upset, bloating or a feeling of fullness. Points to keep in mind:
- Fish allergy: avoid marine collagen if you are allergic to fish.
- Pregnancy and breastfeeding: consult your doctor before use.
- Medicines: speak to your doctor if you take regular medication, especially blood thinners such as warfarin or diabetes medicines. Radia also contains CoQ10 and black pepper extract (piperine), which can affect how some medicines work or are absorbed.
- Do not exceed the recommended daily dose.
Who might consider a marine collagen supplement?
- Adults who want to support skin hydration and firmness as part of their routine
- People who prefer a fish-based collagen to beef or pork
- Those who want collagen, hyaluronic acid and antioxidants in one daily capsule
Frequently asked questions
Which is the best collagen supplement for skin?
Look for hydrolysed collagen peptides, a clearly stated amount per serving, and supporting nutrients such as vitamin C and hyaluronic acid. Choose a format you will take daily. Radia combines marine collagen peptides with hyaluronic acid, vitamin C and antioxidants in two capsules a day.
Is marine collagen better than bovine collagen?
Neither has been clearly shown to be better for skin. Marine collagen suits people who avoid beef or pork; bovine collagen is often cheaper in powder form.
How long does collagen take to work?
Studies usually measure skin changes after 8–12 weeks of daily use. Results vary from person to person.
Can vegetarians take marine collagen?
No. Marine collagen comes from fish. Vegetarian "collagen boosters" contain no collagen.
Can I take collagen with other supplements?
Usually, yes. Check labels so you do not double up on ingredients such as vitamin C, zinc or CoQ10, and ask your doctor if you take regular medication.
Further reading
- Benefits of marine collagen: what the research shows for skin, hair and joints
- Collagen-rich foods for skin: animal sources and vegetarian options
- Marine collagen side effects: what to know, who should avoid it and marine vs bovine
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This information is for general education and is not medical advice. Food supplements are not intended to diagnose, treat, cure or prevent any disease. Consult a qualified healthcare professional before starting any supplement, particularly if you are pregnant, breastfeeding, have a medical condition or take medication.
Sources: Myung SK, Park Y. Effects of collagen supplements on skin aging: a systematic review and meta-analysis of randomized controlled trials. The American Journal of Medicine, 2025. doi:10.1016/j.amjmed.2025.04.034. Radia ingredient amounts from the product label.
