Collagen supplements are everywhere – pills, powders, liquids, gummies – and to make it even more confusing, they come from different sources and with a chorus of conflicting opinions on which is best for you. The biggest debate? Marine collagen vs. bovine collagen. Some swear by one, some by the other, especially when it comes to skin.

So, which actually deserves a spot in your routine? We’re cutting through the noise with the facts, benefits, and what marine or bovine collagen actually does for your skin. As Natalie Rouse, Registered Nutritionist (ANutr) and Head of Nutrition at Free Soul, says, “Both marine and bovine collagen provide peptides your body can use, but it’s important to understand how they differ. The variations in peptide size, as well as composition, directly influence how suitable they are for skin support”.

First things first  - What actually is Collagen?

Collagen, the most plentiful protein in your body, is the building block for skin, bones, ligaments, and connective tissues. While 28 types of collagen have been identified, the ones most commonly found in supplements are:

• Type I – Gives structure and strength to skin, bones, tendons, and ligaments
• Type II – Found mainly in cartilage, where it plays an essential role in joint support
• Type III – Provides elasticity for skin, muscles, organs, and blood vessels

From our mid to late twenties, collagen levels naturally begin to decline. That’s when Type I becomes especially important for maintaining skin’s structure and elasticity. For a detailed guide on the importance of this protein, take a look at our article: “What is collagen and why do I need it?”.

Now we’ve covered the basics, let's dive into marine collagen vs. bovine. 

Marine Collagen

This form is derived from the scales, skin, and bones of fish. It’s primarily composed of Type I collagen, the type most abundant in your skin, hair, and nails. It is also the most easily absorbed form of collagen.

“Marine collagen is typically smaller than those that come from bovine sources, also known as having a smaller molecular weight. This means they’re more easily broken down and absorbed in the gut,” says Natalie. “Also, because they’re rich in Type I collagen, the same type most abundant in the dermis, marine collagen is particularly well matched for supporting skin structure”. 

Bovine Collagen

Bovine collagen is sourced mainly from cow hide and is a mix of Type I and Type III collagen. It’s still bioavailable, but the peptide size is bigger than that of marine collagen, which may affect how easily it's absorbed.

“Type III collagen also plays a role in skin elasticity, but because bovine has less Type I, it’s generally referred to as an all-rounder, supporting not just skin, but also joints and connective tissues,” says Natalie. 

Main benefits of Marine Collagen for skin

Thanks to its richness of Type I, marine collagen has been associated with numerous skin benefits, including:

• Hydration and moisture – Some research suggests that Type I collagen supplementation may support skin hydration and barrier function
• Elasticity and firmness – Marine collagen has been studied for its contribution to skin elasticity, with reported benefits for firmness and the appearance of wrinkles
• Dermal structure support – Type I collagen is the most dominant form found in the dermis (the middle layer of skin) where it provides the framework for smoothness and strength
• Superior absorption – Collagen from marine sources is known to absorb up to 1.5 times better than from bovine sources, so the body can use it more efficiently 

“Collagen makes up around 70-80% of the dry weight of your skin," says Natalie. “Clinical studies suggest that marine collagen peptides may contribute to dermal density over time, with observed improvements in skin elasticity, hydration, and the appearance of fine lines”. 

Marine Collagen vs Bovine Collagen - Which is better for skin?

Here’s a quick reference guide on bovine collagen vs marine collagen for skin, so you can see how they stack up at a glance. 

How to choose the right Collagen supplement

The best collagen for you depends on your goals, but here are some tips to guide your choice:

Pick your priority

If skin, hair and nails are your main focus, then marine collagen (with its high Type I concentration) is your most targeted option. However, if you also want to support your joints and tendons, then bovine collagen will help.

Think about absorption

Go for hydrolysed collagen peptides, as these are broken down into smaller fragments that your body can absorb more easily. Marine Collagen peptides are naturally smaller, which is why they’re a popular choice in beauty-focused supplements.

Check the label

Ingredient lists aren’t the most exciting read, but it’s always best to know exactly what you’re putting into your body. Avoid excessive sugar, fillers, and artificial additives

Look for supporting nutrients

Look for a product that combines collagen with other ingredients that support your goals. For skin, vitamin C, which contributes to normal collagen production, and hyaluronic acid, which helps maintain skin hydration, are ideal extras. 

Consider sustainability

Marine Collagen is typically made from the byproducts of the fish industry, which would otherwise go to waste. Bovine collagen, however, is a product of cattle farming, which has a higher environmental impact. 

Overall, for skin, marine collagen takes the crown for ease of absorption and Type I concentration. But if your goals are bigger than beauty, bovine may be a good option. 

Want to learn more?

• What is collagen and why do I need it?
• 4 daily habits for glowing skin