Compare collagen supplements on what's actually in the serving: how many grams of collagen you get each day, where it comes from, which certifications it holds, and what else has been added. Collagen has no approved health claims of its own in the UK, so we'll tell you honestly what the evidence does and doesn't show. We do the research. You make the choice.
Collagen powder · Capsules & gummies · Marine collagen · Bovine collagen · Vegan collagen builders · Collagen for joints · Hair, skin & nails · Biotin · Beauty supplements
Filters
Clear all
What is collagen, and what's in a collagen supplement?
Collagen is a protein and one of the main building blocks of the body, including skin. Collagen supplements are usually powders, liquids or pills, and Which? notes that the body can't absorb collagen as it is: it builds its own collagen from amino acids.
On the label you'll usually see "hydrolysed collagen" or "collagen peptides", plus the source: marine (fish) or bovine (cattle). Many products also add vitamins, minerals or other ingredients, which is where most of the differences in price and claims come from.
Do collagen supplements work?
The honest answer is that the evidence is mixed: Which? reports there is no scientific consensus that collagen supplements improve skin health, and that any changes are likely to be small. It also notes that collagen itself carries no approved skin claims, which is why you won't see us make them.
Which? points out that there are very few long-term studies, many trials are funded in part or fully by the companies selling the products, and most involve a narrow group of people. "Where evidence is limited or inconclusive, we should say so openly," says Andy Arshad, who runs SupplementHQ.
How much collagen do you actually get per serving?
It varies a lot, so check the grams of collagen per daily serving rather than the pack size or the headline on the front. Which? found servings ranging from 12,600mg to 20,000mg across the products it looked at.
"Collagen products can look very similar on the shelf but differ significantly in formulation, quality, sourcing and the amount of collagen customers actually receive," says Andy, who has worked on developing collagen supplements. "Some powders provide 10g of collagen per serving, while gummies and capsules often provide considerably less. Customers may assume they're getting equivalent products when the actual daily collagen intake is very different."
How to compare value (example figures, not real products): a £30 powder giving 30 daily servings of 10g of collagen costs £1.00 per 10g. A £20 pack of gummies giving 30 daily servings of 2g costs about 67p a day, but £3.33 per 10g of collagen. Our guide to reading a supplement label shows where to find these numbers.
Marine or bovine collagen: what's the difference?
The main difference is the source: marine collagen comes from fish and is rich in type I collagen, while bovine collagen comes from cattle and is rich in types I and III. Which? notes that the idea of marine for skin and bovine for joints hasn't been confirmed by enough research.
"Choosing between marine and bovine collagen isn't simply about which is better," says Andy. "It involves understanding the source, collagen peptide specifications, traceability, manufacturing standards, price and suitability for different consumers. Neither source is automatically superior for every intended benefit."
| Type | Source | Worth knowing |
|---|---|---|
| Marine collagen | Fish (some from shellfish) | Rich in type I collagen; fish and shellfish are regulated allergens |
| Bovine collagen | Cattle | Rich in types I and III; not automatically halal |
| Vegan "collagen" | No collagen | Collagen is only found in animal protein, so these contain other ingredients such as amino acids and vitamin C |
| Collagen for joints | Varies | Often type II collagen; check the source and the amount per serving on the label |
Is collagen halal?
Only if the finished product has been certified: bovine collagen isn't automatically halal just because it comes from cattle. Look for halal certification of the product you're buying, not just a claim about the ingredient.
"The animal source, slaughter method, processing and supply chain must meet the relevant requirements," says Andy. "I've learned the importance of obtaining appropriate documentation and distinguishing between a halal-suitable ingredient and a finished product that has actually been certified."
Is there vegan collagen?
No: Which? explains that collagen is only found in animal protein, so there's no such thing as vegan collagen. Products sold as "vegan collagen" contain other ingredients, such as amino acids and vitamin C, instead.
If you avoid animal products, look at our vegan collagen builders and check exactly what each one contains per serving.
Why is vitamin C added to collagen supplements?
Vitamin C is one of the few ingredients in this category with an approved claim relating to collagen: "vitamin C contributes to normal collagen formation for the normal function of skin". That claim can only be used where a product is at least a source of vitamin C, as defined in law, so check the amount per serving.
Biotin is similar: it has approved claims that it "contributes to the maintenance of normal hair" and "normal skin", again only where the product is at least a source of biotin. "Adding more ingredients doesn't automatically make a product more effective," says Andy. "Each ingredient needs a clear purpose, an appropriate dose and evidence supporting its intended use." Browse biotin and hair, skin & nails supplements.
Collagen powder, capsules, gummies or liquid?
Powders often give you more collagen per serving and can be stirred into a drink, while capsules and gummies are convenient but often contain considerably less per serving. Compare every format on grams of collagen per daily serving and the cost of that serving.
Browse collagen powder or collagen capsules & gummies, and check how many capsules or gummies make up one daily serving.
Is collagen a protein? Can it replace protein powder?
Yes, collagen is a protein, so it counts towards the protein on the label. But collagen supplements are sold for a different purpose from protein powders, so if your main goal is getting more protein, compare our protein powders on cost per 25g of protein instead.
Some people take collagen alongside creatine or protein; check the label of each product and avoid doubling up on added vitamins.
Are there side effects, and who should check first?
Collagen supplements are generally considered safe, according to Which?, with some users reporting minor digestive issues. The bigger things to check are allergens and the extra vitamins many products contain.
Some marine collagen is sourced from shellfish, and fish and shellfish are allergens that must be emphasised on the label. If a collagen product adds vitamin C, zinc or biotin, count them alongside any other supplements you take. If you're pregnant or breastfeeding, take medication, or have a medical condition, speak to your GP or pharmacist first.
What's the best collagen supplement?
There isn't one best collagen supplement for everyone, and a higher price, a marine source or a longer ingredients list doesn't automatically mean better results. The right one gives you a clear amount of collagen per serving, from a source that suits you, at a cost per serving that makes sense.
"A good collagen product isn't necessarily the one with the most impressive marketing," says Andy. "It's one with transparent ingredients, appropriate dosing, reliable sourcing and honest claims." That's how we compare collagen at SupplementHQ: collagen per serving, source, added ingredients, cost per daily serving, certifications and the strength of the evidence.
Start with the format and source that suit you: collagen powder, marine or bovine.
We sell the products on this page. That's our commercial interest, and it's why we show the evidence alongside them. This page is general information for adults, not personalised medical advice.
Written by Andy Arshad, SupplementHQ. Last reviewed 10 October 2026.