Collagen has quickly become one of the most talked-about ingredients in modern beauty, but few people realise that by the age of 25, our natural production has already begun to decline.
Estimates suggest a reduction of approximately 1–1.5% per year, influenced by intrinsic ageing, UV exposure, oxidative stress and lifestyle factors (Reilly et al., 2021).
As interest in collagen supplementation continues to rise, one question appears time and time again: marine or bovine: which is actually better for skin?
Collagen and Skin Structure
Collagen is the most abundant protein in the human body and provides structural support to connective tissues not exclusively to the skin, but also to cartilage, tendons and ligaments.
Natural collagen production changes with age, and factors such as UV exposure, oxidative stress and diet can all influence this process.
Collagen accounts for roughly 30% of total body protein and forms the extracellular matrix that supports dermal strength and elasticity (Varani et al., 2006).
Among the many identified collagen types, three are most relevant in human physiology:
- Type I – The most abundant form in skin, bone, tendons and ligaments
- Type II – Found primarily in cartilage
- Type III – Present in skin, blood vessels and internal organs
Human skin is composed predominantly of Type I collagen, with smaller contributions from Type III (Reilly et al., 2021). This distribution is central when assessing collagen sources.
Marine Collagen: Type I–Dominant
Marine collagen is derived from fish skin and scales and consists primarily of Type I collagen.
When hydrolysed through enzymatic processing, marine collagen peptides are broken down into smaller molecular weight fragments that are highly soluble and more easily absorbed through the digestive tract.
Marine collagen peptides contain a complete profile of 18 amino acids, including glycine, proline and lysine, which are key building blocks of collagen and other connective tissues.
Clinical evidence supports the use of hydrolysed collagen peptides for skin outcomes. A 2023 systematic review and meta-analysis of 26 randomised controlled trials concluded that daily collagen peptide supplementation significantly improved skin hydration, elasticity and dermal density when consumed consistently for 8–12 weeks at a 2.5mg daily dose (Pu et al., 2023).
Several of the included trials utilised marine-derived collagen, with studies showing improvements in skin elasticity and wrinkle depth compared to placebo (Evans et al., 2021).
Bovine Collagen: Type I and III Combination
Bovine collagen is typically sourced from cow hide and connective tissue and contains a combination of:
- Type I collagen
- Type III collagen
Like marine collagen, bovine collagen is commonly hydrolysed to enhance digestibility and peptide absorption.
Clinical studies investigating collagen peptides often include bovine-derived sources and demonstrate improvements in skin elasticity and hydration compared to placebo (Sibilla et al., 2015). However, most trials assess the benefits of collagen peptides broadly rather than directly comparing marine and bovine sources head-to-head
Collagen Absorption and Bioavailability
Following ingestion, hydrolysed collagen peptides are absorbed as small peptides and amino acids and transported via the bloodstream to tissues, including the dermis (Zague, 2008).
Marine collagen is often described as having a lower average molecular weight compared to some bovine preparations, which may support efficient absorption. However, degree of hydrolysis and manufacturing standards significantly influence bioavailability across both sources.
Emerging evidence suggests that hydrolysed marine collagen peptides may be absorbed up to 1.5-times more efficiently than collagen derived from land mammals such as bovine sources, likely due to their lower molecular weight and enhanced intestinal bioavailability (Bartoletti, 2025).
In practical terms, consistent daily intake appears more influential than source alone when evaluating measurable skin outcomes (Pu et al., 2023).
The Role of Vitamin C in Collagen Formation
Regardless of source, collagen synthesis depends on adequate vitamin C.
Vitamin C functions as a cofactor for prolyl hydroxylase and lysyl hydroxylase, enzymes responsible for stabilising the collagen triple helix and enabling proper cross-linking of fibres (Shoulders & Raines, 2009).
Without sufficient vitamin C:
- Newly synthesised collagen lacks structural stability
- Fibroblast activity is impaired
- Collagen production slows
Choosing a Collagen Supplement
Not all collagen supplements are created equal. For optimal skin collagen formation, look for a formula paired with Vitamin C at a meaningful daily dose, the essential co-factor in the body’s natural collagen synthesis process.
Look for collagen that is highly soluble and easily digested (hydrolysed peptides), with clear traceability of sourcing and transparent quality control processes. Certifications related to sustainability and responsible fishing practices can also indicate higher raw material standards, while manufacturing under HACCP and GMP conditions supports product integrity and safety.
If your goal is to support dermal structure, consider marine collagen, which is predominantly Type I collagen, the primary collagen type found in human skin.
Skin resilience develops gradually and is best supported through consistent, high-quality collagen intake over time.