Home / Field guides / Reading a Collagen Label: Grams per Serving and the 2.5 g Reference
Field guide
Reading a Collagen Label: Grams per Serving and the 2.5 g Reference
A collagen label states one figure that the collagen rankings turn on: how many grams of collagen a serving holds, printed as a row with an amount of its own. A scoop weight, a protein line or a blend total is not that figure. This guide covers where the collagen row sits, how the shelf's labels state it, the reference dose it is audited against, and how cost per gram is worked out.
The counts below are computed each time the site is built, from the label data of the 50 collagen products this site publishes. Each count names what it is out of.
Where the collagen figure sits
On a Supplement Facts panel, collagen is a row with an amount, in grams or milligrams: "Collagen Peptides (from bovine) 10 g", or "Hydrolyzed Collagen 2,500 mg". The row's name often says where the collagen comes from, such as bovine hide, fish or chicken, and sometimes which type it is.
Rows called collagen peptides, hydrolyzed collagen or collagen hydrolysate are recorded as the same active, the reference's Collagen Peptides entry, and where a label prints more than one such row with an amount, they are added together.
Some collagen powders carry a Nutrition Facts panel with a protein line. 42 of 50 labels on this shelf print a protein figure. This shelf does not use it: the dose audit and the price use the collagen row, not the protein line.
What the shelf's labels state
- Collagen in an amount of its own: 39 of 50 labels state collagen in an amount outside any blend.
- No such amount: 11 of 50. Of those, 7 of 11 list collagen sources inside a blend with no amount of their own, and 4 of 11 name collagen with no amount.
- Grams per serving: across the 39 labels that state an amount, the median is 10 g.
- At or above the reference dose: 36 of 39 labels that state an amount.
- How the row is named: 34 of 50 labels have a collagen row whose name contains "peptide", 22 of 50 one that says "hydrolyzed" or "hydrolysate", and 12 of 50 one that names a type by number ("Type" followed by a numeral, such as Type I or Type 1 & 3). These are counted from the row names in the label data.
Multi-collagen blends
A "multi-collagen" label often prints one total, such as "Multi Collagen Blend 10 g", and lists the sources beneath it (bovine, fish, chicken, eggshell membrane) with no amount for each. The total states the blend's weight; it does not say how much of each source a serving holds.
The site does not count a blend's total as collagen. The dose audit and the price use only amounts stated for collagen rows outside a blend, and a blend member with no amount of its own counts as undisclosed, which scores zero for label disclosure. This holds even where every member of the blend is a collagen source. The proprietary blends guide covers how blends are read.
The reference dose: 2.5 g
| Ingredient | Reference dose | Source |
|---|---|---|
| Collagen Peptides (audited on Collagen only) | 2.5 g trial dose | Proksch et al., Skin Pharmacol Physiol 2014;27:47-55 (PMID 23949208) — randomized double-blind placebo-controlled trial dosing 2.5 g and 5.0 g/day for 8 weeks in 69 women aged 35-55 (peer-reviewed trial) |
The threshold is grams of collagen peptides, not grams of powder. It is the lower of the two daily amounts the cited trial gave, and it is a dose a trial used, not a recommendation. It is applied on this shelf only: the protein bars and snacks that list collagen as a protein source are not measured against it. The collagen peptides ingredient page compares each product's verified collagen with this figure.
Dose integrity is 20% of this shelf's score. A label is credited in proportion up to the reference dose and no further, so a 10 g serving and a 2.5 g serving earn the same dose credit, and a proprietary blend costs points there too. The reference doses guide explains why going past a reference dose earns nothing extra.
Serving size and servings
The serving size line says what one serving is: a scoop in grams, a number of capsules or caplets, or a measure of liquid. The collagen row is for that serving, so a panel whose serving is "6 caplets" states the collagen in six. A scoop's weight in grams is not its collagen: a flavoured scoop can weigh more than the collagen row it carries.
When a size is priced, its servings are the count its store option prints, where it prints one ("25 Servings"). Where the option names none, they come from the package's weight over the serving weight on the label, from its count of capsules or caplets, or from the label's own servings per container. A printed count far from what the package itself gives is taken for a listing error and not used. The full rule is on how we rate.
From label to cost per gram
On this shelf, value is 30% of the score, and it is built on cost per gram of the labelled active:
- Price per serving: the store price divided by the servings in that size. Where a product is sold in several sizes, the lowest price per serving among the sizes on sale up to 5 kg is used.
- Grams per serving: the grams of collagen the label states in rows of their own, outside any blend. No other row is counted, whatever else the label doses.
- Cost per gram: price per serving divided by those grams.
A label that states no collagen amount of its own has no cost per gram.
The two products below are hypothetical, with round numbers chosen to show the arithmetic. They are not real products.
Tub A costs $30.00 for 30 servings, each with 10 g of collagen.
- Price per serving: $30.00 ÷ 30 = $1.00
- Cost per gram: $1.00 ÷ 10 = $0.10
Capsules B cost $20.00 for 50 servings, each with 2.5 g of collagen.
- Price per serving: $20.00 ÷ 50 = $0.40
- Cost per gram: $0.40 ÷ 2.5 = $0.16
Per serving, B looks cheaper. Per gram of collagen, A costs less. Today 34 of 50 collagen products have a cost per gram, with a median of $0.088 across those 34. The budget collagen page lists the shelf ordered on it.
The rest of the score
- Label disclosure (35%): the share of the label's actives it puts a number against. A blend member with no amount scores zero.
- Buyer rating (15%): shown on the brand's own product page, with the rules on how we rate.
Common label patterns
- An amino acid profile under the panel. Some labels add a list of amino acids per serving, such as glycine, proline and hydroxyproline, describing the amino acids the collagen is made of. The label data records those rows as printed. None of those rows is counted in the cost per gram above, which counts collagen rows only.
- Added vitamin C. 13 of 50 labels print a vitamin C row with an amount. Those rows are not matched to any reference entry, so they are printed on the product page and are not part of the score.
- Other added ingredients. Hyaluronic acid and biotin appear on some labels. The reference recognises them and gives them no threshold:
| Ingredient | Why it is not scored |
|---|---|
| Hyaluronic Acid | no concentration-response is established, and molecular weight is not disclosed |
| Biotin | no established dose outside diagnosed deficiency |
- A figure only on the front. A large "20 g" on the front of the tub is not a panel row, and only panel rows are recorded.
Every weighting and threshold the site uses is on how we rate. To compare products on cost per gram, start with the collagen rankings, or see every figure cheapest first: collagen cost per gram.