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Two tubs of collagen sit on the same shelf. One is £24 for 300g of powder. The other is £38 for 30 small bottles. Both promise firmer skin and happier knees. Per gram of actual collagen, the bottles cost roughly four times as much, and neither label hides that. You just have to do the division.
Collagen supplements aren’t really one product. They’re a family of options that differ in source, format, dose and price structure, and each one trades something away. Here’s how the main choices compare, where each falls short, and which trade-offs are usually worth accepting.
Source first: bovine, marine, porcine, eggshell
Almost everything sold as a collagen supplement is hydrolysed collagen peptides, meaning animal collagen broken into short chains so it dissolves in liquid and gets absorbed. The source shifts the amino acid profile a little, the price a lot, and the taste somewhat.
Bovine (cow hide and bone)
Contains mostly type I and type III collagen, the types found in skin and bone. It’s the cheapest per gram of any source, which is why most budget tubs are bovine. A typical scoop is 10–15g and dissolves in hot or cold liquid. The flavour is mild but present in plain water; most people mask it in coffee, yoghurt or a smoothie. Not an option if you’re pescatarian or vegetarian.
Marine (fish skin and scales)
Largely type I, and the source most heavily marketed for skin. Marine peptides tend to be shorter, which some brands claim improves absorption, though head-to-head human trials against bovine are thin. Expect to pay 20–40% more per gram. Two practical points: it smells fishier if you’re sensitive, and because it’s a fish product, third-party heavy metal testing is worth looking for on the label rather than assuming.
Porcine and eggshell membrane
Porcine collagen is common in European pharmacy brands and behaves much like bovine. Eggshell membrane is a different beast: it isn’t hydrolysed collagen, doses are tiny (300–500mg), and the research is mostly around joint stiffness rather than skin. Cost per gram looks alarming, cost per month doesn’t, because you’re taking so little.
- Cheapest per gram: bovine powder, by a clear margin
- Best for pescatarians: marine powder
- Easiest to take on the move: liquid shots or capsules
- Weakest evidence base: “collagen builder” products with no collagen in them
- Most likely to be overpriced: gummies with 2g of collagen and 4g of sugar
Format decides your real dose
This is where most buying decisions actually go wrong. People pick a format for convenience, then quietly take a fraction of the dose they think they’re getting.
Powder
Best value and the only realistic way to hit 10g a day without swallowing a fistful of capsules. Downside: it’s a ritual. If you don’t already make a hot drink or smoothie every morning, the tub will sit at the back of the cupboard.
Capsules
Each capsule holds around 500mg. You need 5 capsules for 2.5g, and 20 for 10g. Capsules make sense for a small maintenance dose and not much else, though they do travel well. There’s a fuller breakdown of how each format trades off in this comparison of collagen powders, pills, liquids and gummies.
Liquid shots
Usually 5–10g of collagen in 30–50ml, often with added vitamin C and flavour. Genuinely convenient, genuinely expensive: cost per gram is often three to four times a powder’s. Worth it only if the alternative is taking nothing.
Gummies
Pleasant, portable, and typically 2–3g of collagen per serving. You’d need to eat a lot of them to reach a studied dose, and you’d be eating a fair amount of sugar alongside. I’d treat them as a soft entry point rather than a serious option.
Dose: the number most labels hope you won’t check
The research isn’t enormously precise, but it clusters. Skin studies have mostly used 2.5–10g a day for 8–12 weeks, with some using as little as 1g. Joint studies tend to sit higher, at 8–12g. Hair and nail trials have used around 2.5g.
Two conclusions follow. First, below about 2.5g a day you’re mostly buying a flavoured drink. Second, you need to give it two to three months before deciding anything, because nothing measurable happens in a fortnight. If you want to work backwards from your own budget and goals rather than guessing, this six-step method with real numbers walks through the arithmetic properly.
One ingredient worth insisting on: vitamin C. It’s a cofactor in collagen synthesis, and a lot of products include 40–80mg. If yours doesn’t, a glass of orange juice does the job.
“Vegan collagen” isn’t collagen
Plants don’t make collagen, so anything sold as vegan collagen is either a marketing relabel of amino acids, or a “collagen builder” mix of vitamin C, zinc, glycine and plant extracts. The logic is reasonable on paper: supply the raw materials and let your body do the building. In practice the evidence is far weaker than for hydrolysed peptides, and you’re paying a premium for ingredients you could buy separately for less.
If you don’t eat animal products, the honest alternative is adequate protein, vitamin C, and the things that actually move the needle on skin ageing: sun protection and a retinoid. That broader comparison of superfoods, supplements and fasting for anti-ageing is a useful reality check on what each approach delivers.
The price-per-gram maths, worked out
Run the numbers once and most of the marketing falls away:
- Bovine powder, 300g tub, 10g serving: about £25–45, so £0.08–0.15 per gram
- Marine powder, 200g tub, £35: roughly £0.18 per gram
- Gummies, 60 at 2.5g each, £20: about £0.13 per gram, plus sugar
- Liquid shots, 30 at 5g, £40: about £0.27 per gram
Note what the gummy costs relative to a good powder while delivering a quarter of the dose per serving. That’s the trade-off in one line.
Blends: paying for company your collagen doesn’t need
A lot of premium tubs now bundle hyaluronic acid, biotin, probiotics or a “beauty complex”. None of it is harmful, and vitamin C is worth having. But every addition raises the price, and few have strong evidence at the doses used. The same bundling trick shows up across the supplement aisle, and there’s a similar analysis of it in this breakdown of supplements for energy and which types justify the spend.
What I’d check on the label in 60 seconds
Whatever source and format you land on, five things separate a sensible buy from an expensive one:
- Grams of collagen per serving, not milligrams of “complex”
- Servings per container, which tells you the true monthly cost
- Hydrolysed or peptides on the ingredients list, ideally with a molecular weight or a stated “low molecular weight” claim
- Third-party testing for heavy metals, especially with marine collagen
- Nothing you’re allergic to hiding in the flavour system
If a tub passes those checks, source matters less than consistency. Ten grams of plain bovine powder taken most days for three months will outperform a fancier product taken sporadically, and it will cost you less than £40. That’s the unglamorous answer, and it’s the one that survives contact with an actual routine. For a closer look at which specific products and forms hold up to scrutiny, what actually works in a collagen supplement digs into the evidence product by product.
Pick the source you can afford at a real dose, the format you’ll genuinely use on a Tuesday morning, and the label with the fewest unproven extras. Everything else is packaging.
