Two collagen products can sit on the same shelf, one offering 10 000 mg in a daily scoop and the other 40 mg in a single small capsule. The difference between the two numbers is a factor of 250. Neither label is wrong. Neither number, on its own, tells you much, because the two products are not the same kind of preparation, were not made the same way and were never tested against the same outcome.
The question behind that confusion is the one we ask at Health Royals before a raw material is chosen: what dose was studied, in whom, for how long, and does the number on our pack match it. So this article goes through what the trials used, why a milligram figure and a gram figure are not on the same scale, how to read the number on a pack, and how we reasoned when we chose our own collagen. We have written separately about what collagen actually is and about the marine types and sources.
Collagen at Health Royals
Beauty Complete contains Cartidyss® fish cartilage collagen from Abyss Ingredients in Brittany, 500 mg per daily dose, the same dose as in the raw material's placebo-controlled study of 46 women over 90 days. It sits alongside Hyabest® hyaluronic acid 120 mg, Ceramosides™ phytoceramides 30 mg, vitamin C 60 mg, vitamin B2 1.4 mg and biotin 50 µg.
How much collagen per day do the studies actually use?
Hydrolysed collagen peptides are given at roughly 2.5 to 10 grams a day, and undenatured type II collagen at 40 milligrams a day.
In a double-blind placebo-controlled study published in Skin Pharmacology and Physiology by Proksch and colleagues, 69 women aged 35 to 55 took either 2.5 g or 5.0 g of collagen hydrolysate daily for eight weeks. A second trial from the same group, published in the same journal, gave 114 women aged 45 to 65 a daily 2.5 g dose for eight weeks and reported a 20 percent reduction in eye wrinkle volume against placebo, together with higher procollagen type I and elastin in the skin samples taken.
Joint trials sit at the top of that range. Zdzieblik and colleagues gave 139 athletic subjects with functional knee pain 5 g of collagen peptides or placebo daily for 12 weeks, reported in Applied Physiology, Nutrition, and Metabolism. Ten grams a day recurs in the older joint literature.
The widest picture is a 2023 systematic review and meta-analysis in Nutrients, which pooled 26 randomised controlled trials and 1721 participants. The doses across those trials ranged from 372 mg to 12 g per administration, over 2 to 12 weeks. A separate meta-analysis of 19 trials and 1125 participants aged 20 to 70, of whom 95 percent were women, appeared in the International Journal of Dermatology in 2021.
So the honest answer to how much collagen per day is that the number depends entirely on what is in the capsule or the scoop.
Why is one collagen dosed in grams and another in milligrams?
Because they are meant to work in different ways, one as material to be absorbed and one as a signal to the immune system.
Hydrolysed collagen has been broken down into short peptides. It is swallowed in grams because it is supplied as raw material, and a meaningful amount has to survive digestion and reach the blood as peptides. The amount is set by absorption, not by a receptor.
Undenatured type II collagen is the opposite proposition. It is deliberately not hydrolysed, because the proposed mechanism depends on the intact triple helix. A review in Animals describes the material being taken up by the Peyer's patches in the small intestine, where it is believed to convert naive T cells into regulatory T cells that specifically target type II collagen. The review notes that a small amount, 40 mg a day, is believed to work by inducing what is known as oral tolerance.
Oral tolerance is a recognition mechanism. It does not need bulk, any more than a vaccine needs to be given by the gram. That is why the trials use 40 mg and not 4 g, and why hydrolysing more collagen into the capsule would destroy the structure the mechanism is thought to read.
In the multicentre trial by Lugo, Saiyed and Lane in Nutrition Journal, 191 people with knee osteoarthritis were randomised to 40 mg of the branded material daily, which the paper states provides 1.2 mg of undenatured type II collagen, or to 1500 mg glucosamine hydrochloride plus 1200 mg chondroitin sulphate, or to placebo, for 180 days. In the earlier trial by Crowley and colleagues in the International Journal of Medical Sciences, the same 40 mg daily dose is described as containing 10 mg of bioactive undenatured type II collagen.
Two papers on the same branded ingredient at the same daily dose describe the active fraction as 1.2 mg and as 10 mg. That is not a scandal, it reflects different assays and definitions of what counts as active, and it is a useful reminder that a milligram figure on its own says little about what a material is.
A milligram figure is therefore not a smaller dose than a gram figure. It is a different sort of preparation, and the two belong on separate scales. This distinction is one reason we do not compare collagen ingredients by milligrams alone. When we selected Cartidyss® for Beauty Complete, we started with the specific raw material and the dose used in its human study.
Why did Health Royals choose 500 mg of fish cartilage collagen?
Because it is a named material with a placebo-controlled human study behind it, and the dose in that study is the dose in the pack.
Fish cartilage is not fish skin. Skin gives type I collagen and very little else. Cartilage gives type II collagen together with chondroitin sulphate and other glycosaminoglycans, so the material is a mixture rather than a single purified peptide, dosed in hundreds of milligrams rather than grams or tens of milligrams. That mixture is why we looked at cartilage rather than skin.
The material is Cartidyss®, a fish cartilage hydrolysate made by Abyss Ingredients in Brittany, a specialist manufacturer of marine raw materials with traceable sourcing and a published human study on its own material. Health Royals works with specialist manufacturers, researchers and supplier networks when raw materials are selected, and this is the kind of manufacturer we look for.
That study, double-blind and placebo-controlled, was published in Molecules in 2021. In it, 46 healthy women aged 45 to 59 took either 500 mg of hydrolysed fish cartilage daily or placebo for 90 days, with 43 completing. The paper reported reductions in periorbital and nasolabial wrinkles along with increases in dermis echogenicity and thickness.
Cartidyss was studied at 500 mg per day. Beauty Complete contains 500 mg per daily dose. That is a decision, not a coincidence: where a branded raw material has a human study, the product carries the dose the study used. For us, the ingredient cannot be separated from its source, manufacturer and studied dose. Ninety days in the study also means taking the product every day for three months, which is why the jar is made to be kept out on a shelf rather than in a cupboard.
The same logic runs through the rest of the formula. Beauty Complete contains six ingredients. Hyabest® hyaluronic acid, 120 mg, is bio-fermented by Kewpie in Japan to a defined molecular weight. Ceramosides™ phytoceramides, 30 mg, are a plant lipid extract from Seppic. Both are named materials at the daily dose used in their own human studies. Vitamin C as PureWay-C, 60 mg, vitamin B2, 1.4 mg, and biotin, 50 µg, are nutrients, and they sit at a nutritional level.
A higher number is not automatically a better or more evidence-based dose. What matters is the specific raw material and the dose that was actually studied.
So there are three dose scales in this category, not one: around 40 mg for undenatured type II, a few hundred milligrams for a cartilage hydrolysate, and grams for a peptide powder. Each number makes sense only on its own scale.
Does a higher dose give a better effect?
More collagen peptides in the mouth do put more collagen peptides in the blood, and the trials point to the studied range rather than to ever larger amounts.
The clearest dose response data comes from a pharmacokinetic study by Shigemura and colleagues in Food Chemistry. Four healthy volunteers took collagen hydrolysate at 30.8, 153.8 and 384.6 mg per kilogram of body weight, which the authors note corresponds to roughly 2, 10 and 25 g for a 65 kg person. Plasma hydroxyproline containing peptides peaked at 6.43, 20.17 and 32.84 nmol per ml respectively. The lowest dose did not produce a statistically significant rise.
Plasma peptide concentration measures absorption. What the study establishes is that the gram range is not arbitrary: below about 2 g there may not be much in the blood to measure.
At the other end, the trials support the studied range. In the 69 woman trial in Skin Pharmacology and Physiology, both the 2.5 g and the 5.0 g arms separated from placebo on skin elasticity, and the published abstract does not report the larger dose beating the smaller. The Nutrients meta-analysis found that effects on hydration varied with the source of the collagen and the duration of supplementation rather than with the amount.
The practical reading: 2.5 to 10 g a day is the studied range for peptide powders, and no published trial shows that going above it adds anything.
What does the research show overall?
Collagen research is best read one preparation and one dose at a time.
Results vary between preparations and outcomes. A 2019 meta-analysis in International Orthopaedics by García-Coronado and colleagues found an effect on the total WOMAC index, and on undenatured type II, a 2025 review by Gupta and Maffulli in Annals of Medicine called for larger and longer trials. The skin trials mostly involve women aged 35 to 65, followed for 8 to 12 weeks.
What the research does show is clear. The peptide dose range has been consistent for thirty years. Absorption is real and dose dependent, as the Shigemura data show. Oral tolerance, proposed for undenatured type II, has been tested in several human trials.
This is precisely why the selection matters: when results vary between preparations, a studied raw material at a studied dose is worth more than a large number on a label.
How does vitamin C relate to collagen?
Vitamin C contributes to normal collagen formation for the normal function of skin. That is the wording authorised in Commission Regulation (EU) No 432/2012, for foods that are at least a source of vitamin C.
It describes the vitamin's role in the collagen your own body builds. Beauty Complete contains 60 mg of vitamin C as PureWay-C, together with 500 mg of Cartidyss®.
Our article on how to read a collagen label goes through the rest of the front of pack language.
How do you read the dose on the pack?
Work out which of the three preparations you are holding before you compare any numbers.
- Identify the type first. Hydrolysed peptides, cartilage hydrolysate and undenatured type II are three different products. A number only means something inside its own category.
- Check that the dose is per daily portion. Some packs print the figure per 100 g of powder, which is not what you are going to take.
- For a peptide powder, look for 2.5 to 10 g a day. That is the range the trials used. Much less has little support, much more has none.
- For undenatured type II, look for 40 mg. A bigger number here is not a better product, and a product advertising grams of type II is not the material the 40 mg trials tested.
- Ask how much of the capsule is the named material. A 1000 mg capsule that contains 100 mg of the studied ingredient is a 100 mg dose.
- Prefer a named raw material. The trial was run on a specific material at a specific dose, and a generic powder at the same weight is not automatically the same thing.
- Prefer a raw material that has been studied at the dose on the pack, from a manufacturer that publishes what it is. That is what a considered selection looks like.
Our skin page collects the wider context on skin.
We have done the selection so that you do not have to. Beauty Complete contains Cartidyss® fish cartilage collagen at 500 mg per daily dose, Hyabest® hyaluronic acid 120 mg, Ceramosides™ phytoceramides 30 mg, vitamin C 60 mg, vitamin B2 1.4 mg and biotin 50 µg. The collagen figure sits on the third scale, at the dose the Molecules study used.
We publish the doses and the studies behind them because that is how we think a supplement should be presented. If the check holds, you can stop looking.
Further reading
- Guide: collagen supplements, form and dose
- Guide: skin from within
- Cartidyss®: the fish cartilage collagen in Beauty Complete, and what its study measured
- How much vitamin C does the skin need for collagen formation?
- Hyabest®: the hyaluronic acid in Beauty Complete, and what the studies measured
Sources
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of a health claim related to collagen hydrolysate and maintenance of joints pursuant to Article 13(5) of Regulation (EC) No 1924/2006. EFSA Journal, 2011. efsa.europa.eu
- Regulation (EC) No 1924/2006 of the European Parliament and of the Council of 20 December 2006 on nutrition and health claims made on foods. EUR-Lex
- Commission Regulation (EU) No 432/2012 of 16 May 2012 establishing a list of permitted health claims made on foods, other than those referring to the reduction of disease risk and to children's development and health. EUR-Lex
- Proksch E, Segger D, Degwert J, Schunck M, Zague V, Oesser S. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study. Skin Pharmacology and Physiology, volume 27, issue 1, pages 47 to 55, 2014. Karger
- Proksch E, Schunck M, Zague V, Segger D, Degwert J, Oesser S. Oral intake of specific bioactive collagen peptides reduces skin wrinkles and increases dermal matrix synthesis. Skin Pharmacology and Physiology, volume 27, issue 3, pages 113 to 119, 2014. Karger
- Zdzieblik D, Oesser S, Gollhofer A, König D. Improvement of activity-related knee joint discomfort following supplementation of specific collagen peptides. Applied Physiology, Nutrition, and Metabolism, volume 42, issue 6, pages 588 to 595, 2017. PubMed
- Pu SY, Huang YL, Pu CM, Kang YN, Hoang KD, Chen KH, Chen C. Effects of oral collagen for skin anti-aging: a systematic review and meta-analysis. Nutrients, volume 15, issue 9, article 2080, 2023. MDPI
- de Miranda RB, Weimer P, Rossi RC. Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis. International Journal of Dermatology, volume 60, issue 12, pages 1449 to 1461, 2021. PubMed
- Shigemura Y, Kubomura D, Sato Y, Sato K. Dose-dependent changes in the levels of free and peptide forms of hydroxyproline in human plasma after collagen hydrolysate ingestion. Food Chemistry, volume 159, pages 328 to 332, 2014. PubMed
- Lugo JP, Saiyed ZM, Lane NE. Efficacy and tolerability of an undenatured type II collagen supplement in modulating knee osteoarthritis symptoms: a multicenter randomized, double-blind, placebo-controlled study. Nutrition Journal, volume 15, article 14, 2016. Springer
- Crowley DC, Lau FC, Sharma P, Evans M, Guthrie N, Bagchi M, Bagchi D, Dey DK, Raychaudhuri SP. Safety and efficacy of undenatured type II collagen in the treatment of osteoarthritis of the knee: a clinical trial. International Journal of Medical Sciences, volume 6, issue 6, pages 312 to 321, 2009. International Journal of Medical Sciences
- Gencoglu H, Orhan C, Sahin E, Sahin K. Undenatured type II collagen (UC-II) in joint health and disease: a review on the current knowledge of companion animals. Animals, volume 10, issue 4, article 697, 2020. PMC
- Gupta A, Maffulli N. Undenatured type II collagen for knee osteoarthritis. Annals of Medicine, volume 57, issue 1, 2025. Annals of Medicine
- García-Coronado JM, Martínez-Olvera L, Elizondo-Omaña RE, Acosta-Olivo CA, Vilchez-Cavazos F, Simental-Mendía LE, Simental-Mendía M. Effect of collagen supplementation on osteoarthritis symptoms: a meta-analysis of randomized placebo-controlled trials. International Orthopaedics, volume 43, issue 3, pages 531 to 538, 2019. Springer
- von Hippel PT. Do collagen supplements reduce symptoms of osteoarthritis? Meta-analytic results do not support strong conclusions. International Orthopaedics, volume 45, issue 12, pages 3283 to 3284, 2021. Springer
- Maia Campos PMBG, Franco RSB, Kakuda L, Cadioli GF, Costa GMD, Bouvret E. Oral supplementation with hydrolyzed fish cartilage improves the morphological and structural characteristics of the skin: a double-blind, placebo-controlled clinical study. Molecules, volume 26, issue 16, article 4880, 2021. PMC
