# Why collagen studies work with fixed gram amounts

> Every third amino acid in collagen is glycine - no other dietary protein is built so lopsidedly. What that means biochemically, and why 30 pre-measured servings are more than convenience.

Collagen is almost always discussed through its effects and almost never through its building blocks. Chemically it is simply a protein - one with a highly unusual amino acid pattern. That pattern is exactly what explains why collagen behaves differently than whey or pea protein.

## Every third amino acid is glycine

Collagen is built as a triple helix: three polypeptide chains winding around each other. For the geometry to work, every third position needs an amino acid with the smallest possible side chain. Only **glycine** qualifies - its side chain is a single hydrogen atom. Hence the Gly-X-Y motif, repeated across hundreds of positions. In numbers: roughly a third glycine, another 22% or so **proline** and **hydroxyproline**.

## Glycine: conditionally dispensable, often short in practice

Glycine counts as non-essential because the body can make it from serine. Meléndez-Hevia et al. (2009) did the arithmetic and reached an uncomfortable result: endogenous synthesis does not, on paper, cover the requirement for full collagen turnover. They describe a gap on the order of ten grams per day. On top of that, glycine also goes into **glutathione**, creatine, heme and bile salts. Anyone eating little connective tissue - skin, cartilage, bone broth - takes in hardly any.

## Hydroxyproline is made after translation

Hydroxyproline appears in no genetic code. It arises when the enzyme prolyl hydroxylase hydroxylates proline that has already been incorporated - and that enzyme strictly requires **vitamin C** as a cofactor (Peterkofsky 1991). For vitamin C the claim "contributes to normal collagen formation" is authorised. For collagen as such, EFSA has approved no health claim - that belongs in an honest assessment.

## Why studies work with fixed gram amounts

Intervention studies do not dose by feel: 2.5 g, 5 g or 15 g per day - the amount is part of the design. König et al. (2018) worked with 5 g daily for twelve months. Anyone estimating at home with a scoop leaves that framework faster than expected: a loosely filled and a levelled scoop easily differ by several grams. Pre-portioned sachets remove the imprecision - every serving is the same serving.

## How WOO® Kollagen Nature is set up in the sachet box

**[WOO® Kollagen Nature](/en/shop/woo-collagen-nature-box)** in the box is 87% collagen hydrolysate and 13% collagen tripeptides from bovine sources, produced in Switzerland. Nothing else: no sugar, no sweetener, no flavouring. Per 15 g sachet that is 14 g of protein, 0 g of carbohydrate and 54 kcal - 30 identically measured daily servings, stirred into 200 ml of water. For the vitamin C cofactor, **[WOO® Beauty Caps](/en/shop/woo-beauty-caps-can)** is the obvious pairing. Lactose-free, gluten-free, not suitable for vegans and vegetarians.

## Frequently asked questions

**How much glycine does one serving provide?**
At roughly a third glycine and 14 g of protein per sachet, about four to five grams. A relevant contribution, but no substitute for a glycine-rich diet.

**Do I have to take vitamin C at the same time?**
Baseline supply matters, not the clock. Collagen in the morning and vitamin C spread across the day covers the cofactor requirement.

**Can collagen replace my protein powder?**
No. Collagen contains no tryptophan and little of several other indispensable amino acids. Paul et al. (2019) place the sensible ceiling at around a third of total protein intake. For protein in general, the authorised claim is that it contributes to the maintenance of normal bones.

## Sources

Meléndez-Hevia E et al. (2009), Journal of Biosciences - A weak link in metabolism: the metabolic capacity for glycine biosynthesis does not satisfy the need for collagen synthesis.
Peterkofsky B (1991), American Journal of Clinical Nutrition - Ascorbate requirement for hydroxylation and secretion of procollagen.
Paul C et al. (2019), Nutrients - Significant amounts of functional collagen peptides can be incorporated in the diet while maintaining indispensable amino acid balance.
König D et al. (2018), Nutrients - Specific collagen peptides improve bone mineral density and bone markers in postmenopausal women.

*WOO® Kollagen Nature in the sachet box - in the NEMAPO shop.*