Collagen

Collagen hydrolysate, Hydrolyzed collagen

Also known as: Collagen peptides, Hydrolyzed collagen, Collagen hydrolysate, Native collagen, Undenatured collagen type II, Marine collagen, Bovine collagen, Porcine collagen

Collagen is the most abundant protein in the human body, providing structural support to skin, bones, tendons, and cartilage. Supplementation may improve skin hydration, elasticity, and joint comfort.

Introduction

Collagen is the primary structural protein in the extracellular matrix of connective tissues, comprising about 30% of total body protein. It provides tensile strength to skin, tendons, ligaments, bones, and cartilage. The body produces collagen naturally, but this production declines by approximately 1% per year after age 20.

Collagen supplements are typically derived from bovine (cow), porcine (pig), marine (fish), or chicken sources. They come in two main forms: hydrolyzed collagen (collagen peptides) broken down into smaller amino acid chains for better absorption, and native/undenatured collagen (particularly type II) that maintains its triple-helix structure.

Research suggests collagen supplementation may stimulate fibroblasts to produce more collagen, elastin, and hyaluronic acid. Bioactive peptides from hydrolyzed collagen may also accumulate in skin and joint tissues, providing direct benefits. For joints, undenatured type II collagen may work through oral tolerance mechanisms to reduce autoimmune responses against joint cartilage.

Most clinical studies focus on cosmetic benefits (skin hydration, elasticity, wrinkle reduction) and joint health (osteoarthritis symptoms, exercise recovery). Effects typically require 4-12 weeks of consistent supplementation to become noticeable.

Main Benefits

Improves skin hydration, elasticity, and dermal collagen density; may reduce visible wrinkles and signs of skin aging.
May reduce joint pain and improve mobility in individuals with osteoarthritis and in athletes experiencing joint stress.
May support bone mineral density and strength when combined with resistance exercise, particularly in postmenopausal women.
Potential benefits for muscle mass and strength when combined with resistance training, though evidence is preliminary.
May improve nail growth and strength, and support hair health, though evidence is limited.

Mechanism of Action

Collagen supplementation works through multiple mechanisms. Hydrolyzed collagen provides bioactive peptides (primarily proline-hydroxyproline-glycine) that are absorbed into the bloodstream and distributed to target tissues. These peptides may act as signaling molecules that stimulate fibroblasts to increase production of collagen, elastin, and hyaluronic acid.

In skin, collagen peptides accumulate in the dermis and may directly contribute to the collagen matrix. They also stimulate hyaluronic acid synthesis, improving skin hydration and plumpness. The antioxidant properties of specific collagen peptides may protect against UV-induced collagen breakdown.

For joint health, hydrolyzed collagen provides building blocks (glycine, proline, hydroxyproline) for cartilage synthesis. Undenatured type II collagen works differently - it passes through the gut lining intact and induces oral tolerance, reducing the immune system's attack on joint cartilage in conditions like osteoarthritis.

Collagen peptides also stimulate osteoblast activity in bone tissue and may improve calcium absorption. The amino acid glycine, abundant in collagen, supports detoxification pathways and may have anti-inflammatory effects.

Natural Sources

Collagen is found in animal connective tissues, particularly in skin, bones, tendons, and cartilage. Dietary collagen comes primarily from consuming these animal parts.

Examples:

Bone broth (chicken, beef, fish)
Chicken skin and cartilage
Fish with skin and bones
Pork skin
Beef tendons and connective tissue
Gelatin (cooked collagen)

Ease of Sourcing from Diet3/10

Modern diets rarely include collagen-rich animal parts (skin, tendons, bones); bone broth provides some collagen but supplementation is more practical for consistent therapeutic doses.

Recommended Daily Intake

No established RDA. Research studies typically use 2.5-15 grams daily of hydrolyzed collagen for skin benefits, and 10-40 mg daily for undenatured type II collagen for joint health.

Reference Values:

Skin health (hydrolyzed)	2.5-10 g/day
Joint health (hydrolyzed)	8-12 g/day
Joint health (undenatured type II)	10-40 mg/day
Bone health	5 g/day
Muscle mass	15 g/day

Sources for RDI/AI:

Effects require 4-12 weeks of consistent use. Higher doses do not appear to provide additional benefits. Take with vitamin C to enhance collagen synthesis.

Effectiveness for Specific Focuses

Skin, Hair & Nails8/10

Strongest evidence base; consistent improvements in hydration, elasticity, and wrinkle depth in multiple clinical trials.

Joint & Bone Health7/10

Good evidence for osteoarthritis symptom relief; native type II collagen shows promise for joint health through oral tolerance.

Athletic Support4/10

Preliminary evidence for muscle mass with resistance training; less effective than protein sources containing all essential amino acids.

Longevity & Aging5/10

May support healthy aging through skin, joint, and bone benefits; no direct evidence for lifespan extension.

Safety Information

Potential Side Effects

Mild digestive upset (bloating, feeling of fullness)
Unpleasant taste or aftertaste
Allergic reactions (if allergic to source animal)

Contraindications

Allergy to fish/seafood (marine collagen)
Allergy to beef or pork
History of kidney stones (theoretical concern with high doses)

Overdose Information

Overdose Risk Level2/10

Very safe; no serious toxicity; amino acid composition similar to dietary protein; no established upper limit needed.

Collagen has an excellent safety profile. It is essentially a food product (hydrolyzed protein). Side effects are rare and mild.

Interactions

Drug Interactions:

None well-documented

Drug Interaction Risk1/10

No known significant drug interactions. Very safe to combine with medications.

Other Supplement Interactions:

Vitamin C - essential cofactor for collagen synthesis; enhances benefits
Hyaluronic acid - may have synergistic effects for skin hydration
Glucosamine/chondroitin - may have additive benefits for joint health

Supplement Interaction Risk1/10

Safe with all supplements; vitamin C is particularly synergistic for collagen production.

Choose source appropriate for dietary restrictions (marine for pescatarians, porcine for those avoiding beef). Vegetarians/vegans should consider that collagen is always animal-derived. Take with vitamin C for optimal collagen synthesis.

Forms and Bioavailability

Hydrolyzed collagen (peptides) is the most common and well-studied form. Undenatured type II collagen is used specifically for joint health at much lower doses.

Hydrolyzed Collagen (Peptides)

Collagen broken down into small peptides (2-3 amino acids) for easy absorption. Most common form in supplements.

Relative Bioavailability8/10

Well-absorbed as small peptides; bioactive dipeptides reach skin and joint tissues; well-studied form.

Most research uses this form. Look for products specifying collagen types I and III for skin, or type II for joints. Dissolves easily in liquids.

Native/Undenatured Type II Collagen

Maintains triple-helix structure; works through oral tolerance at very low doses (10-40 mg).

Relative Bioavailability7/10

Different mechanism (immune modulation) than hydrolyzed collagen; effective at much lower doses for joint health.

Specifically for joint health and autoimmune-related joint issues. Not processed/hydrolyzed, so intact collagen reaches immune cells in gut.

Gelatin

Partially hydrolyzed collagen; larger peptides than hydrolyzed collagen; creates gel when cooled.

Relative Bioavailability6/10

Less hydrolyzed than collagen peptides; larger peptides may be less efficiently absorbed but still beneficial.

Used in cooking (desserts, soups). Good for joint and gut health but less convenient than powdered peptides for supplementation.

Marine Collagen

Sourced from fish; primarily type I collagen; smaller peptide size claimed for better absorption.