The Science Behind Collagen Peptides: Benefits, Bioavailability and How They Work

Collagen peptides have become one of the most talked-about ingredients in beauty and wellness – and for good reason. They’re backed by a robust body of scientific evidence showing real benefits for skin health, from improving hydration, elasticity and barrier function, to reducing the appearance of fine lines and wrinkles.

But what exactly are collagen peptides? How do they work once we ingest them? And is there a difference between hydrolysed collagen peptides and tripeptides? In this article, we’ll break down the science of collagen so you can make informed decisions about your beauty routine.

What is a peptide?

In the simplest terms, peptides are short chains of amino acids – the building blocks of proteins. Think of them as the “language” your body uses to build, repair, and send signals to your cells (including your skin) and tissues.

Peptides occur naturally in the body, but they’re also found in foods and can be created in laboratories for a range of uses. In medicine, certain peptides are used as drugs (like insulin, a peptide hormone that regulates blood sugar, or GLP-1s like Ozempic for weight management).

And in nutrition, collagen peptides – derived from animal or marine collagen – can stimulate the body’s own collagen production in the deeper dermal layers of the skin.

The science behind peptides and absorption

When we consume protein in food (such as meat, fish, or legumes), our digestive system breaks it down into smaller units – peptides and amino acids – so they can be absorbed into the bloodstream.

Hydrolysed collagen peptides are already pre-broken down from their original form (native collagen), which makes them more bioavailable – meaning they can be efficiently absorbed and utilised by the body.

Why bioavailability matters

Studies have shown that after ingesting collagen peptides, small peptide fragments can be detected in the blood within an hour, where they act as “messengers” to stimulate fibroblasts – the skin cells responsible for producing new collagen, elastin, and hyaluronic acid¹.

The degree of hydrolysation and the size of the collagen peptides is the most critical element to the clinical effectiveness of a collagen supplement.

This is why bioavailability matters: the easier it is for the body to absorb and use a nutrient, the more likely it will deliver visible, measurable results.

Is hydrolysed marine collagen different to collagen peptides?

You may have seen both terms – hydrolysed collagen and collagen peptides – used on supplement packaging. In practice, they mean the same thing, however, the size of the peptide is the most important factor, and this is not always evident on the label.

What is hydrolysis?

Collagen is a large, complex protein that’s too big for the body to absorb in its whole form. Through a process called enzymatic hydrolysis, collagen is broken down into smaller, more absorbable peptide chains. These are what we call collagen peptides or hydrolysed collagen. Imagine hydrolysis as a pair of scissors cutting long chains into smaller little chains (peptides) for enhanced absorption. 

What type of collagen peptides are best for skin?

Marine collagen peptides (derived from fish skin) have superior bioavailability compared to bovine or porcine sources, thanks to its smaller particle size and high proportion of type I collagen – the type most abundant in our skin. A recent systematic review and meta-analysis found that marine collagen delivered the most potent skin anti-ageing effects relative to other collagen sources².

The difference between collagen peptides and tripeptides

While “collagen peptides” is the umbrella term for hydrolysed collagen fragments, collagen tripeptides are a very specific type of peptide – made up of just three amino acids in a precise sequence that has fascinating effects in the skin.

Tripeptide benefits for skin

The best-known example is Gly-Pro-Hyp, which research suggests is particularly effective at stimulating collagen synthesis in fibroblasts³. Tripeptides are absorbed intact directly through the intestinal wall and can be delivered directly to skin cells, where they bind to specific receptors and trigger collagen production in several ways. Not only do they increase production, but they also increase the number of fibroblasts (the cellular machinery that produces collagen), having a multi-pronged effect.

Should I take collagen peptides or tripeptides?

Think of it like retinoids in your topical skin care: collagen peptides are like retinol – effective and well-researched – while collagen tripeptides are like retinoic acid – more targeted, with a faster, more direct action. Both work well, but tripeptides are more potent at lower doses, providing accelerated results.

A clinical trial comparing collagen tripeptides with standard collagen peptides found that the tripeptide group experienced greater improvements in skin hydration, elasticity, and dermal density over 8 weeks⁴. At Vida Glow we have invested in our own clinical and consumer research for our advanced solution ProCollagen+ containing marine collagen tripeptides which has replicated these findings.

The bottom line on collagen peptides

Collagen peptides are a scientifically validated way to support the skin’s natural structure from the inside out. Once absorbed, they act as both building blocks and biological signals, helping your body bridge the gap and replenish collagen production that naturally declines with age.

Hydrolysed marine collagen and collagen peptides are essentially the same thing – the difference lies in the source, the quality of processing, hydrolysis technology and the size of the collagen peptide. Tripeptides, on the other hand, are a specialised form that may offer more targeted skin benefits and superior results due to their very low molecular size.

At Vida Glow, we focus on clinically studied forms of collagen – whether peptides or tripeptides – so that every dose you take is working as hard as you are for visible, lasting results.

References:

1. Ohara, H. et al. (2007). Collagen-derived dipeptide and tripeptide in human blood after oral ingestion of gelatin hydrolysate. Journal of Agricultural and Food Chemistry, 55(4), 1532–1535.

2. Pu SY, Huang YL, Pu CM, Kang YN, Hoang KD, Chen KH, Chen C. Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis. Nutrients. 2023 Apr 26;15(9):2080. doi: 10.3390/nu15092080. PMID: 37432180; PMCID: PMC10180699.

3. Shigemura, Y. et al. (2009). Effect of prolyl-hydroxyproline intake on skin conditions and cell proliferation in human fibroblasts. Journal of Agricultural and Food Chemistry, 57(2), 444–449.

4. Yazaki, M. et al. (2017). Oral intake of collagen tripeptide improves skin barrier function and hydration levels in healthy adults: A randomized, double-blind, placebo-controlled study. Journal of Functional Foods, 35, 271–279.