Everything you need to know about collagen: the ultimate guide

It's being talked about everywhere: on social media, in gyms, and even in dermatologists' offices. Collagen has become the undisputed star of dietary supplements. But is it just a fad or a genuine biological necessity?

If you're wondering what the difference is between marine and bovine collagen, whether it really works for wrinkles or tendonitis, and how to dose it, you've come to the right place.

Here's everything science says about collagen, without unnecessary jargon.

What is collagen?

Collagen is the most abundant protein in the human body. Think of it as the "glue" that holds everything together. It makes up about 30% of the total protein in our body and provides structure to our skin, tendons, bones, muscles, and blood vessels. Pretty impressive, right?

Why are we lacking them?

From the age of 25, our natural collagen production begins to decline (approximately 1% to 1.5% less each year).

By the age of 40 , we have lost a significant amount of it.
At 60 , our reserves are drastically reduced.

It is this deficiency that leads to the appearance of wrinkles, sagging skin, joint pain and ligament fragility.

The 5 Proven Benefits of Collagen

Why are more and more people taking it? Here are the effects validated by recent clinical studies:

Anti-aging and Skin Beauty

This is the number one reason for purchases. Collagen supplementation improves skin elasticity and hydration, and reduces the depth of wrinkles. It helps to "plump" the dermis from within (see diagram above).

Joint and Tendon Health (Sport)

For athletes (weightlifting, running, CrossFit), collagen is crucial. It strengthens connective tissues (tendons and ligaments), reducing the risk of injury and accelerating recovery after tendinitis.

Osteoarthritis Relief

Studies show that collagen (particularly Type II) can reduce pain associated with osteoarthritis and improve joint mobility in older people.

Muscle Mass (Sarcopenia)

Combined with resistance training, it helps combat age-related muscle loss.

Hair and Nails

It provides the necessary amino acids (glycine, proline) to strengthen keratin, making nails less brittle and hair more resistant.

Which type of collagen to choose?

There are several types of collagen, each with a specific role in the body.

Type I collagen is the most abundant: it makes up the skin, bones, tendons, and ligaments. It's the type to prioritize for improving skin firmness, strengthening connective tissues, and supporting athletic recovery, especially for runners and endurance athletes.
Type II collagen , on the other hand, is concentrated in cartilage and is more suited to people suffering from joint discomfort or seeking to preserve joint flexibility.
Finally, type III collagen often accompanies type I, as it structures organs and promotes better tissue elasticity. For athletic activity or performance goals, the combination of types I and III is generally the most relevant, while type II is ideal for specifically targeting joint health.

Marine or Bovine Collagen: What are the differences?

This is the most frequently asked question. The answer depends on your goals.

Characteristic	Marine Collagen (Fish)	Bovine Collagen (Beef)
Source	Fish skin, bones and scales	Bovine skin, bones and cartilage
Dominant type	Type I (Similar to that of human skin)	Type I and III (Sometimes Type II for cartilage)
Absorption	Often considered slightly superior (smaller molecules)	Very good if hydrolyzed
Best for...	Skin , hair, anti-aging	The intestines , overall recovery, the joints
Price	Generally more expensive	Often more affordable

For purely aesthetic purposes (wrinkles, radiance), choose marine oil. For overall health, a tight budget, or significant joint recovery, bovine oil is excellent.

Is there vegan collagen (made from algae)?

Technically, no. Collagen is an animal protein. Products sold as "vegan collagen" are actually boosters (mixtures of vitamins and amino acids) meant to help your body produce its own collagen, but it's not pure collagen.

How to choose the right collagen? (Quality Criteria)

Don't be fooled by marketing. Check these 3 points on the label:

Hydrolyzed (or Collagen Peptides): Native collagen is too large a molecule to be digested. It must be broken down into peptides (through hydrolysis) to pass through the intestinal barrier. Make sure the packaging clearly states "hydrolysate" or "peptides."
Molecular weight: This is measured in Daltons (Da). Aim for a low weight, ideally less than 2000 or 3000 Daltons, for maximum absorption (the well-known Naticol or Peptan label is a guarantee of quality). A collagen molecule weighs 30,000 Da in its raw state.
The presence of Vitamin C: Vitamin C is essential for collagen synthesis in the body. If your powder does not contain it, eat a piece of fruit or take a vitamin C tablet at the same time.
The origin of fish for marine collagen: Several labels and certifications are recognized as guarantees of fishing that respects marine resources.

Marine Stewardship Council (MSC) : the most internationally recognized label for sustainable wild-caught fishery. It certifies that fish come from sustainably managed fisheries, that stocks are preserved, and that environmental impacts are reduced.
Friend of the Sea (FoS) : a European/international label that covers both wild-caught and farmed fish. It verifies that the fish or seafood products used meet strict standards of sustainability, species preservation, and traceability.
Aquaculture Stewardship Council (ASC) — especially relevant if the marine collagen comes from farming: this label certifies responsible aquaculture, respectful of the environment, marine populations and good farming practices.
Sustainable Fishing (French label): for products from French fisheries that meet criteria for sustainability, limited environmental impact and good fishing practices.

Dosage: How many grams per day?

Forget about capsules, which often contain micro-doses (500mg). Studies are clear: you need quantity.

For the skin: 2.5g to 5g per day.
For joints and sports: 10g to 20g per day.

Tip: Opt for powder rather than capsules. To get 10g of collagen, you would need to swallow 20 giant capsules! A scoop of powder in a glass of water is much simpler.

Does collagen cause weight gain?

No. It's a pure protein, very low in calories (about 36 kcal per 10g). It can even help with satiety.

When should it be taken?

The timing doesn't matter. In the morning with a coffee, in the afternoon with a yogurt, or in the evening. What matters is regularity.

How long does it take to see the effects?

It's not magic.

Skin: Initial results after 4 to 8 weeks.
Joints: Allow 3 to 6 months of daily use to experience lasting relief.

Why choose Mulebar collagen?

Choosing Mulebar marine collagen means choosing premium quality and scientifically validated effectiveness to support your body on a daily basis.

Formulated with Naticol® type I and III collagen, this supplement stands out for its high bioavailability: thanks to its patented hydrolysis process (low molecular weight peptides of approximately 2000 Da), it is perfectly assimilated by the body to act deep within your tendons, ligaments, joints, and skin. Ideal for endurance athletes as well as active people wishing to age better, it promotes recovery, joint comfort, and skin elasticity.

Furthermore, Mulebar is committed to ethics and transparency with a 100% natural product, made in France and sourced from sustainable fishing certified by Friend of the Sea .

Convenient, its neutral-tasting powder blends easily into your drinks or smoothies; a simple 5g dose is enough to replace a dozen conventional tablets.

Collagen isn't just a beauty product; it's an essential health ally after age 30, and even more so if you're an athlete. To start, choose hydrolyzed collagen powder, aim for 10g per day, and be patient: consistency is key to success.