# Hydration, elasticity, density: what is actually measurable in skin

> "Firmer skin" is a claim, not a measurement. Which quantities collagen studies actually recorded - and how to observe your own eight to twelve week cycle properly.

"Firmer skin" is a claim, not a measurement. Dermatology, by contrast, has defined quantities: skin hydration, elasticity, roughness, density. Anyone assessing collagen should know which of these were actually measured in studies.

## What holds the dermal matrix together

The dermis consists largely of collagen types I and III - around three quarters of its dry weight. Between them sit **elastin**, which provides recoil, and **hyaluronan**, a sugar polymer that binds many times its own weight in water. What we perceive as moisture and firmness is the interplay of these three.

## Two ageing routes: time and UV

The intrinsic route runs over decades: less active fibroblasts, slower remodelling, a thinner dermis. The second route is faster and externally caused. Fisher et al. (1997) showed that irradiation below the reddening threshold already triggers the formation of **matrix metalloproteinases** in human skin - enzymes such as MMP-1 that cleave collagen type I. The distinction matters in practice: a supplement addresses the first route, sun protection the second.

## What intervention studies actually measured

Proksch et al. (2014) studied 69 women over eight weeks with 2.5 or 5 g of collagen peptides daily and found significantly improved skin elasticity versus placebo. Asserin et al. (2015) added a look at the dermal collagen network and skin moisture. Bolke et al. (2019) measured hydration, elasticity, roughness and density over twelve weeks.

The meta-analysis by de Miranda et al. (2021), covering 19 studies with around 1,100 participants, shows: consistent but moderate effects on hydration and elasticity. Moderate does not mean irrelevant - it means nobody has a different face after two weeks. EFSA has approved no health claim for collagen as such; vitamin C, by contrast, contributes to normal collagen formation.

## Observing yourself, but with method

In the lab, skin hydration is measured by corneometry. At home the comparison stays subjective - but it can be improved considerably: same time of day, same light, no make-up, one photo at the start and every four weeks. And change only one variable at a time. Anyone who switches sleep, skincare routine and supplement simultaneously will not know at the end what did the work. The observation period follows the studies: eight to twelve weeks.

## How WOO® Kollagen Pfirsich is dosed from the tub

**[WOO® Kollagen Pfirsich](/en/shop/woo-collagen-peach-can)** supplies 85% collagen hydrolysate and 13% collagen tripeptides from bovine sources, plus 2% mango fruit powder with the Careflow® extract, peach flavouring, citric acid and steviol glycosides. One serving is a 15 g scoop in 200 ml of water: 13 g of protein, under 0.1 g of sugar, 53 kcal.

The 450 g tub holds 30 servings - exactly one cycle of the kind studies use as a minimum. For the vitamin C cofactor, **[WOO® Beauty Caps](/en/shop/woo-beauty-caps-can)** is the obvious pairing. Not suitable for vegans and vegetarians.

## Frequently asked questions

**When can anything be expected at the earliest?**
Studies with positive results run eight to twelve weeks.

**How large are the effects?**
The meta-analysis speaks of moderate but consistent improvements in hydration and elasticity.

**Does collagen replace sun protection?**
No. UV-induced matrix metalloproteinases are the strongest known external factor in skin ageing - only protection helps against that.

## Sources

Fisher GJ et al. (1997), New England Journal of Medicine - Pathophysiology of premature skin aging induced by ultraviolet light.
Proksch E et al. (2014), Skin Pharmacology and Physiology - Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology.
Asserin J et al. (2015), Journal of Cosmetic Dermatology - The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network.
Bolke L et al. (2019), Nutrients - A collagen supplement improves skin hydration, elasticity, roughness and density.
de Miranda RB et al. (2021), International Journal of Dermatology - Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis.

*WOO® Kollagen Pfirsich in the tub - in the NEMAPO shop.*