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PeptideClear UK

Collagen head to head

Type I vs Type II collagen

Type I and Type II are different molecules taken at different doses for different goals. Type I is taken in grams (hydrolysed) for skin and tendon. Type II is taken in milligrams (UC-II, undenatured) for joints. They are not substitutes. A daily collagen routine targeting both skin and joints would typically combine 10 g Type I plus 40 mg UC-II.

Type I Type II (UC-II)
Where it sits in the body Skin, hair, nails, tendons, bone Cartilage
Typical source Bovine, marine, porcine Chicken sternum cartilage
Standard form Hydrolysed peptides (3 to 6 kDa) Undenatured (UC-II)
Standard dose 5 to 15 g per day 40 mg per day (UC-II)
Mechanism Amino acid pool + signal peptides Oral tolerance: immune-mediated joint effect
Evidence base Mixed, mostly industry-funded RCTs UC-II: small but consistent joint comfort RCTs
Best for Skin appearance, tendon recovery, gut lining Knee comfort, joint stiffness
Cost per month £20 to £35 (10 g/day) £20 to £40 (40 mg/day, 30 caps)

Cross-reference: collagen Type I, II, III deep-dive.

Reviewed by Oliver Mackman, editorial director · last reviewed 2026-05-18