The Absorption Problem Nobody Mentions on the Collagen Tin: Which Types Actually Get Through

Why I Still Get Asked About Collagen Every Single Week

After thirty years behind a supplement counter, collagen is still one of the top five questions I get. And the confusion is completely understandable. The market is a mess. You have got cheap tubs next to expensive sachets next to marine capsules, all making broadly similar noises on the label, all at wildly different prices. A customer came in last month holding a tub she had bought from a supermarket. She wanted to know why she had taken it for three months and noticed nothing. I took one look at the label and understood immediately. The collagen in that tub was not going to do much of anything, not because collagen does not work, but because that particular product was not in a form her body could actually use.

That is the conversation I want to have here. Not what collagen will do for your health, but what makes one collagen supplement worth your money and another one a waste of it.

The Absorption Problem Nobody Mentions on the Tin

Collagen is a protein. A very large protein. In its raw form, a collagen molecule is too big to pass through the gut wall in any meaningful quantity. Your digestive system will break it down, yes, but not in a way that delivers intact peptides your body can use efficiently.

This is where hydrolysis comes in. Hydrolysed collagen, sometimes listed as collagen peptides or collagen hydrolysate, has been broken down into much shorter chains. Those shorter chains are small enough to be absorbed intact through the intestinal lining. If the collagen has not been hydrolysed, or has been hydrolysed poorly, you are paying for protein powder at collagen prices. And not even particularly good protein powder.

The cheap tub my customer brought in? Non-hydrolysed gelatin-based collagen. Useful for making jelly. Not useful as a daily supplement.

The Different Types, and Which Ones Matter

The label will often say Type I, Type II, or Type III. Sometimes all three. Here is what those actually mean in practical buying terms:

• Type I - The most abundant collagen in the body. Found in skin, tendons, ligaments and bone. This is what most collagen products are built around. Marine collagen is typically Type I and is known for its small peptide size, which supports absorption.
• Type II - Found primarily in cartilage. Often used in formulas aimed at joint support. Typically sourced from chicken sternum. Native undenatured Type II works differently from hydrolysed, so if joints are your specific concern, talk to your GP about what might be relevant for you.
• Type III - Found alongside Type I in skin and blood vessel walls. Often appears in bovine collagen products alongside Type I.
• Marine collagen - Sourced from fish skin or scales. Predominantly Type I. Peptides tend to be smaller than bovine, which may support absorption. A sensible choice if you avoid beef.
• Bovine collagen - Sourced from cow hides. Contains Type I and Type III. The most common source in powders. Quality varies enormously depending on the hydrolysis process and the source of the cattle.

The type matters less than the form. Hydrolysed always wins over non-hydrolysed, regardless of source.

What the Label Should Actually Say

Here is the quick version of what to look for when you are standing in a shop or reading a product page:

• Hydrolysed collagen or collagen peptides - This tells you the protein has been broken into absorbable chains. If the label just says collagen, ask how it has been processed.
• Molecular weight in Daltons - Better brands will specify this. Lower molecular weight, generally under 5,000 Daltons, means smaller peptides and better absorption potential.
• Vitamin C inclusion - Vitamin C contributes to normal collagen formation. A formula that includes it is not a gimmick. It is sensible formulation backed by EFSA authorisation.
• Transparent sourcing - Grass-fed bovine or sustainably sourced marine. The quality of the source animal affects the quality of the collagen extracted from it.
• Collagen content per serving in grams - Some products are mostly maltodextrin with a token amount of collagen. Check the actual collagen gram weight, not just the total powder weight per serving.

Comparing Collagen Sources: A Practical Buying Table

On that last row: there is no such thing as plant collagen. Plants do not make it. What you get in a vegan collagen product is a blend of nutrients that contribute to your body's own collagen synthesis. Vitamin C, zinc, silica. That is not fraud exactly, those are legitimate nutrients, but the label using the word collagen is misleading. Know what you are buying.

The Product I Actually Recommend in the Shop

I stock a range of collagen products. The one I reach for most often when someone wants a properly formulated option is the Collagen Pro-Factors 150g Powder by Viridian. It is hydrolysed, it includes supporting nutrients such as Vitamin C and zinc, and Viridian are transparent about what goes in and why. No padding. No nonsense. It is the kind of product where I can read the label out loud and not feel embarrassed by any of it.

Collagen Pro-Factors 150g Powder by Viridian
View in the shop

If someone mentions gut health in the same conversation, which happens more than you might expect, I might also point them toward L-Glutamine Powder 100g by Viridian. Two different products doing two different jobs, but they are often relevant to the same person.

How Long Should You Give It

This is the question I get every time. The honest answer is that collagen is not a one-week product. The tissue you are trying to support turns over slowly. Most people who report noticing anything are using it consistently for eight to twelve weeks minimum. If you stop after three weeks because nothing dramatic happened, you have wasted your money. That applies to most supplements, not just collagen. For more on that, have a read of Do supplements really actually work? where I cover that whole subject properly.

FAQ

From the shop