Quick Answer: "Type II" and "hydrolysed" describe different things. Type II is a collagen type found in cartilage. Hydrolysed means the collagen has been broken down for absorption. You can have hydrolysed Type II collagen, hydrolysed Type I collagen, or non-hydrolysed versions of either. For most dogs, hydrolysed Types I and III collagen provides the most comprehensive support because it addresses the entire joint structure, not just cartilage.
You're comparing collagen supplements and seeing confusing terms.
One says "Type II collagen." Another says "hydrolysed collagen peptides." A third says "undenatured Type II."
What's the difference? Which one actually works?
Let's clear this up.
The Two Different Questions
When choosing a collagen supplement for your dog, you're actually answering two separate questions:
Question 1: What TYPE of collagen?
- Type I (skin, bones, tendons, ligaments)
- Type II (cartilage)
- Type III (skin, blood vessels, gut lining)
Question 2: How is it PROCESSED?
- Hydrolysed (broken down into small peptides)
- Undenatured/Native (intact collagen molecules)
These are independent. You can have:
- Hydrolysed Type I collagen
- Hydrolysed Type II collagen
- Undenatured Type II collagen
- Hydrolysed Types I and III combined
The confusion happens when people compare "Type II" against "hydrolysed" as if they're opposites. They're not. They're answers to different questions.
Understanding Collagen Types
Type I Collagen
- Where it's found: 90% of your dog's total collagen
- What it supports: Skin, bones, tendons, ligaments, connective tissue around joints
- Why it matters: Provides structural support for the entire joint, not just cartilage
Type II Collagen
- Where it's found: Primarily in cartilage
- What it supports: The cushioning surface within joints
- Why it matters: Specific to cartilage health
Type III Collagen
- Where it's found: Alongside Type I in skin, blood vessels, gut lining
- What it supports: Skin elasticity, gut integrity
- Why it matters: Works with Type I for comprehensive support
The reality: Joint health isn't just about cartilage. Tendons, ligaments, and connective tissue all matter. Types I and III support the whole structure.
Understanding Processing Methods
Hydrolysed Collagen (Collagen Peptides)
- What it means: Collagen broken down into small peptide chains (typically 2,000-5,000 Daltons)
- How it works: Small peptides absorb through the gut, travel in bloodstream, accumulate in tissues
- Absorption: Studies show high intestinal absorption
- Use: Provides building blocks for the body to make new collagen
Undenatured/Native Collagen
- What it means: Collagen in its original, intact form (around 300,000 Daltons)
- How it works: Proposed to work through immune modulation rather than direct absorption
- Absorption: Not absorbed intact; too large to pass through gut wall
- Use: Theoretically "trains" the immune system to stop attacking cartilage
The key difference: Hydrolysed collagen provides raw materials for repair. Undenatured collagen attempts to modulate immune response. Different mechanisms entirely.
What the Science Says
Hydrolysed collagen peptides:
Research shows that hydrolysed collagen peptides are absorbed from the gut and accumulate in cartilage and other connective tissues. Studies by Oesser and others demonstrated that these peptides can stimulate collagen-producing cells.
This mechanism is well-understood: provide building blocks, support tissue repair.
Undenatured Type II collagen:
The research here is more limited. The proposed mechanism is "oral tolerance" where small amounts of intact collagen train the immune system. Some studies show benefit, but the evidence base is smaller.
This mechanism is less direct: attempt to modulate immune response to cartilage.
Which Should You Choose?
For most dogs, hydrolysed Types I and III collagen is the practical choice.
Here's why:
Broader support: Types I and III make up 90%+ of your dog's collagen. They support tendons, ligaments, skin, gut, and the connective tissue surrounding joints. Not just cartilage.
Proven absorption: Hydrolysed peptides demonstrably absorb and reach target tissues.
Simpler mechanism: Providing building blocks for repair is straightforward and well-evidenced.
Better value: Hydrolysed collagen supplements are typically more affordable.
When Type II might be considered:
- Dogs with immune-mediated joint issues (rare, vet diagnosis required)
- As an addition to, not replacement for, Types I and III support
- When specifically recommended by a veterinary specialist
The "Undenatured Type II" Marketing
You'll see supplements marketed as "UC-II" or "undenatured Type II collagen."
What to understand:
- These products contain very small amounts of collagen (often 40mg vs 3,000-6,000mg in hydrolysed products)
- They work through a completely different mechanism (immune modulation vs tissue building)
- They're not "better" than hydrolysed collagen; they're different
- They don't provide building blocks for tissue repair
The marketing often implies that Type II is superior because it's "specific to cartilage." But joint health involves far more than cartilage alone.
Frequently Asked Questions
Is Type II collagen better than Type I for joints?
Not necessarily. Type II is specific to cartilage, but joints also depend on tendons, ligaments, and connective tissue (supported by Types I and III). Comprehensive support typically works better than cartilage-only approaches.
Should I choose hydrolysed or undenatured collagen?
For most dogs, hydrolysed. It provides actual building blocks for tissue repair with well-documented absorption. Undenatured collagen works through immune modulation, which is less relevant for typical age-related or wear-and-tear joint issues.
Can I give both types?
Yes, they work through different mechanisms and don't interfere with each other. However, for most dogs, hydrolysed Types I and III collagen provides sufficient support without adding complexity.
Why do some supplements combine multiple types?
Marketing appeal, mostly. The body can use hydrolysed peptides from any type as building blocks. A quality hydrolysed Types I and III product covers most needs.
Our Approach
Our Pure Collagen and Mobility & Joints products use hydrolysed collagen peptides providing Types I and III.
We chose this approach because:
- Types I and III support the entire joint structure
- Hydrolysed peptides have proven absorption
- The mechanism (providing building blocks) is well-understood
- It offers comprehensive support for joints, skin, coat, and gut
Follow the serving guide on your product's pouch based on your dog's weight.
The Bottom Line
- "Type II" and "hydrolysed" answer different questions (what type vs how processed)
- Hydrolysed Types I and III provides comprehensive joint support with proven absorption
- Undenatured Type II works through immune modulation, a different and less direct mechanism
- For most dogs, hydrolysed collagen peptides are the practical, evidence-based choice
- Don't be swayed by marketing implying Type II is inherently superior
Focus on quality hydrolysed collagen given consistently, rather than getting caught up in type debates.
Sources
- Oesser S, Seifert J. Stimulation of type II collagen biosynthesis and secretion in bovine chondrocytes. Cell and Tissue Research, 2003
- Bui TM, Wieser J. Bioavailability of collagen peptides. Journal of Agricultural and Food Chemistry, 2019
- Deparle LA, et al. Efficacy of undenatured type II collagen in dogs with osteoarthritis. JAVMA, 2005
- British Small Animal Veterinary Association
Important: This information is for educational purposes and doesn't replace veterinary advice. If your dog is showing signs of joint problems, consult your vet for proper diagnosis and treatment.
Last Updated: February 2026
