Collagen has become one of the most-marketed words in wellness, on coffee creamers, gummies, face creams and protein powders. Strip away the marketing and there's a real, well-understood biology underneath.
The starting point
Most abundant, and quietly declining
of all the protein in your body is collagen, the single most abundant protein you have.
is roughly how much collagen production falls each year from your mid-20s onward.
What collagen actually is
Think of collagen as scaffolding. It's a structural protein your body weaves into long, strong fibres that give tissue its shape, strength and stretch. It makes up the majority of your skin's dry weight, a large share of your bones, and the bulk of your tendons, ligaments and cartilage. Where other proteins do jobs, carrying oxygen, driving reactions, collagen mostly holds things together.
It's built from a distinctive, repeating amino-acid pattern, unusually rich in three: glycine, proline and hydroxyproline. That sequence is what lets collagen fibres coil into their characteristic rope-like triple helix.
Why you lose it with age
From your mid-to-late 20s, the cells that produce collagen gradually slow down, and existing fibres break down faster than they're replaced, a net loss of roughly 1% a year. It's slow and invisible at first, then increasingly visible as skin loses firmness and joints lose some of their cushioning.
For women, there's a sharper inflection at menopause. In the first five years after menopause, skin collagen can fall by around 30% as oestrogen declines, with the elastic Type III dropping fastest.
The decline
Roughly how skin collagen falls with age
Does eating collagen actually do anything?
When you eat collagen, you don't absorb it whole and ship it to your face, your gut breaks it down into amino acids and small peptides, just like any protein. For years that was the basis for scepticism: surely it just becomes generic protein?
The picture turned out to be more interesting. Collagen-specific peptides, particularly the glycine–proline–hydroxyproline sequence, are absorbed intact enough to appear in the bloodstream after a dose, where they appear to act as both building blocks and signals that nudge the body to produce more of its own collagen.
What the trials show
The evidence, in brief
Improved hydration & elasticity vs placebo
Meta-analysis of 26 RCTs, 1,721 people (2023)
Reduced osteoarthritis pain & better function
Meta-analyses of RCTs (WOMAC scores)
Associated with reduced bone-density loss
Reported in controlled studies
One important cofactor: your body can't build collagen without vitamin C. Pairing collagen-rich food with vitamin-C-rich food (fruit in a smoothie) is a sensible move.
Where collagen comes from, food vs supplements
Here's a fact that reframes the whole category: collagen exists only in animal connective tissue. There is no collagen in any plant. So your sources fall into a clear spectrum: whole-food (bone broth, slow-cooked cuts), isolated (hydrolysed collagen peptides), or "not collagen" (plant products supplying precursors only).
Isolated vs whole-food collagen
Most collagen on the market follows the same pattern as the additives in a typical shake: a product is built from isolated protein, then a scoop of hydrolysed collagen powder is added back on top as a premium feature. It's collagen as an ingredient you add. The alternative is collagen as a property of what the food already is, never removed, so never needing to be added back.
Across The Real Food Scale assessment, bone broth is the one only Tier 1 whole-food collagen sources. Most "collagen" products are isolated peptide powder added back to a stripped-down base.
How WholeFuel approaches it
Everything above is why we didn't bolt a scoop of isolated collagen powder onto a formula. WholeFuel's collagen is already there, because of what it's made from, around 7g per serving from bone broth, alongside whole egg and other real-food proteins that round out a complete amino-acid profile.