The collagen you swallow does not become the collagen in your skin

The implied promise of a collagen supplement is a supply chain: drink collagen, arrive as collagen, end up in skin. That isn’t how protein works. Collagen is far too large to cross the gut wall intact. Stomach acid and digestive enzymes break it into peptides, and most of those into individual amino acids, which enter the bloodstream and join the same free amino acid pool as the protein in your dinner.

From there the body allocates. It builds what it currently needs - enzymes, immune proteins, muscle, gut lining, skin - according to demand, not according to what the tub said. Glycine and proline are useful raw materials for collagen synthesis, but supplying more of them does not instruct a fibroblast to build more collagen, any more than delivering more bricks instructs a builder to start work.

This is the part the category rarely mentions. Unlike fat and carbohydrate, the body has no store for surplus amino acids. There is no protein reserve to draw on later. Anything above immediate demand is deaminated in the liver: the nitrogen is stripped off and excreted as urea, and the carbon skeleton left behind is fed into metabolism.

Where it goes from there is standard biochemistry. Glucogenic amino acids - glycine, proline and alanine among them, which is most of what collagen is made of - are converted through pyruvate into glucose or stored as glycogen. Ketogenic amino acids feed into acetyl-CoA, and in a calorie surplus that pathway ends in fat. Either way the amino acid stops being a building material and becomes fuel or storage.

So a daily scoop of collagen taken on top of an already adequate protein intake is not banked for your skin. It is oxidised, converted, or stored, and the wrinkle it was bought for is unaffected.

If you eat enough protein, you are not short of glycine or proline. What changes with age is the cell’s ability to do the work: fibroblasts turning over collagen, repair enzymes clearing damage, mitochondria funding all of it. Every one of those processes runs on energy, and skin is metabolically expensive tissue that renews constantly.

NAD⁺ is the coenzyme that funds it. Mitochondria use it to turn food into energy; repair enzymes need it to work at all. It declines steadily with age, and when supply is short the body prioritises - energy production is non-negotiable, structural maintenance is deferrable. Skin sits firmly in the deferrable column.

Which reframes the question. Adding more raw material to a system that is short of energy doesn’t produce more collagen. It produces more surplus.

MUTO doesn’t supply building blocks. It works on the layer beneath - producing NAD⁺, protecting it from being broken down as fast as it is made, and giving the cell what it needs to spend it. Skin health follows from cellular energy and repair rather than from a delivery of protein the body was never short of.

Every dose is at the level used in the research it comes from, printed in full on the label. No proprietary blends, nothing you can’t check against what you already take.

MUTO was formulated by Dr Richie Barclay and reviewed by a six-person scientific advisory board before a single capsule was made. It’s produced in a UK facility to GMP ISO standard and tested by an independent lab for purity and potency.