Quick answer
- Collagen has no authorised health claim in the UK or EU. Claims on the pack come from added vitamin C or magnesium.
- Studies typically use 2.5–10 g of collagen a day. Many tablet products give only a few grams, and only at the full daily dose.
- A 2025 meta-analysis of 23 trials found skin benefits only in industry-funded studies; independent trials found none.
- If the product contains magnesium, count it: keep total magnesium from supplements under 250 mg a day.
Key numbers
- Collagen dose used in studies
- 2.5–10 g/day
- Authorised claims for collagen (UK and EU)
- None
- A joint claim for collagen hydrolysate was refused in 2012.
- Vitamin C for the "collagen formation" claim
- from 12 mg per daily dose
- Magnesium from supplements (EFSA safe level)
- 250 mg/day
- Relevant for collagen with magnesium.
What these terms mean: NRV upper levels (NHS, EFSA) maximum levels by country daily dose
How to choose
- Find the grams of collagen per daily dose and how many tablets or scoops that takes.
- Powders usually give more collagen per euro than tablets; compare the cost per 10 g of collagen.
- Check the source if you have allergies: marine collagen comes from fish.
- For combinations, add up the magnesium, vitamin C or hyaluronic acid and check you are not doubling up with other products.
- Treat promises about wrinkles, hair or joint pain as marketing: none of them is an authorised claim.
Types of collagen supplement
| Type | What it is | Good to know |
|---|---|---|
| Hydrolysed collagen (peptides) | Collagen broken into small peptides; bovine, porcine or fish | The form in most products and studies |
| Marine collagen | Hydrolysed collagen from fish skin or scales | No proven advantage; not for fish allergy |
| Branded peptides (e.g. Verisol, Peptan) | Specific hydrolysates used in some trials | Results apply to that ingredient and dose only |
| Undenatured type II (UC-II) | Small doses (around 40 mg) of native cartilage collagen | Marketed for joints; works differently from peptides |
| Gelatin | Partly broken-down collagen | Cheap; same building blocks |
What the evidence says
For skin, a 2025 meta-analysis pooled 23 trials with 1,474 people. Overall results suggested better hydration and elasticity, but the benefit appeared only in industry-funded trials; independent and higher-quality studies found no effect. Manufacturers dispute that reading. For joints, trials at 5–10 g a day are mixed, with at most a small benefit.
That is why so many collagen products add magnesium, vitamin C or hyaluronic acid. Our guide on collagen with magnesium or hyaluronic acid shows what each combination may legally claim and how to check the dose.
What the label may legally claim
Authorised claims (GB and EU registers)
- None for collagen itself. Added vitamin C may claim that it contributes to normal collagen formation for the normal function of skin, cartilage and bones.
- Added magnesium (from 56 mg) may claim bones, muscle function and reduction of tiredness and fatigue.
Not authorised in GB or the EU
- Fewer wrinkles or younger-looking skin
- Healthy joints or less joint pain
- Stronger hair and nails
How health claims work (UK & EU): health claims
Products we have checked
Label data checked by NutriMetrics for products sold in Spain and Germany. UK product checks are next. Sorted alphabetically, not ranked.
| Product | Per daily dose | Sold in | Label |
|---|---|---|---|
| Aldous Cápsulas Colágeno + Ácido Hialurónico2 capsules a day Only 0.8 g of collagen a day, far below the 2.5–10 g used in studies. | 0.8 g · hydrolysed bovine | Spain | Source |
| Ana María Lajusticia Colágeno con magnesio (comprimidos)6 tablets a day | 3.6 g | Spain | Source |
Who should be careful
- Fish allergy: avoid marine collagen unless the label confirms it is safe for you.
- Vegans and vegetarians: collagen is made from animal tissue. Products sold as "vegan collagen" contain no collagen, only amino acids or vitamins.
- Kidney disease: be careful with collagen products that add magnesium, and ask your GP.
FAQ
Does collagen work for skin?
The evidence is disputed. A 2025 meta-analysis of 23 trials found improvements in skin hydration and elasticity only in studies funded by manufacturers; independent and higher-quality trials found no effect.
How much collagen should I take a day?
Studies typically use 2.5–10 g a day. Check how many tablets you need to reach that: with some tablet products it is six or more.
Is marine collagen better than bovine collagen?
There is no good evidence that one source works better than another. Compare grams per daily dose and price, and avoid marine collagen if you are allergic to fish.
Sources
- DHSC — Great Britain nutrition and health claims (NHC) register
- Myung SK, Park Y. Effects of collagen supplements on skin aging: systematic review and meta-analysis. Am J Med, 2025 (summary and industry response)
- Commission Regulation (EU) No 379/2012 — refusal of health claims, including collagen hydrolysate
- European Commission — EU Register of nutrition and health claims
- Commission Regulation (EU) No 432/2012 — list of permitted health claims
Information only, not medical advice. No product on this page is a paid placement.