Collagen Peptides
Hydrolysed protein that supports skin, hair, nails and joints
What is Collagen Peptides?
Collagen is the most abundant protein in the human body, comprising roughly 30% of total protein mass. It forms the structural scaffold of skin, tendons, ligaments, cartilage, bone, and blood vessels. The body produces collagen from amino acids (particularly glycine, proline, and hydroxyproline), but production declines 1–1.5% per year from our mid-20s. Hydrolysed collagen peptides are pre-digested fragments (typically 2–8 kDa) that are highly bioavailable.
How it works
Unlike most proteins, collagen peptides appear to have targeted effects beyond simple amino acid provision. Specific dipeptides (Pro-Hyp, Hyp-Gly) are absorbed intact and accumulate in skin, cartilage, and other connective tissues. They stimulate fibroblasts to increase collagen synthesis — effectively signalling that collagen breakdown has occurred and more needs to be made. They may also promote hyaluronic acid production in skin.
What the evidence shows
Skin: A 2021 systematic review (19 RCTs) showed collagen peptide supplementation significantly improved skin elasticity, hydration, and wrinkle depth. Joint: Multiple RCTs in athletes and osteoarthritis patients show reduced pain and improved function. Hair/nails: A 2017 study showed 5g/day for 24 weeks improved nail brittleness and growth rate by ~12%. Bone: Studies show positive effects on bone mineral density in postmenopausal women.
When to expect results
Nail growth may speed up slightly. Skin hydration improving. No major visible changes yet.
Improved skin texture and reduced dryness. Joint comfort improving in people with mild pain.
Visible improvement in skin elasticity. Reduced wrinkle depth measurable. Hair becoming thicker and stronger.
Full structural collagen rebuilding. Athletes report better joint resilience and faster connective tissue recovery.
Dosing
5–15g hydrolysed collagen peptides daily. Most trials showing skin benefits use 2.5–10g. Joint studies often use 10–15g (sometimes as undenatured type II for joint specifically). Take with vitamin C — it's required for collagen cross-linking and may enhance the stimulating effect on fibroblasts. Ideally consume 30–60 minutes before exercise (joint collagen synthesis peaks post-ingestion during tissue stress).
Forms to choose
Hydrolysed collagen (collagen peptides, collagen hydrolysate): best absorbed, most studied for skin and joints. Type I (from bovine/porcine/marine): skin, hair, nails, tendons. Type II (from chicken cartilage, often undenatured): specifically for joint cartilage. Marine collagen: type I, slightly smaller peptides, some claim better absorption. Bovine is most affordable. Vegan collagen doesn't exist — avoid misleadingly named products.
Who benefits most
Adults over 25 concerned about skin ageing, people with joint pain or active lifestyles with high connective tissue stress, athletes (tendons and ligaments are slow to heal — collagen supports recovery), women experiencing postmenopausal bone loss, anyone with brittle nails or hair thinning.
Who should avoid / caution
People with phenylketonuria (PKU — contains phenylalanine). Vegans (no plant-based equivalent exists). People with specific protein allergies to the source (fish, beef, pork).
Interactions & stacking
Vitamin C is essential for collagen synthesis (hydroxylation of proline and lysine). Take together for maximum effect — especially before exercise.
Collagen provides structural protein; hyaluronic acid provides hydration and cushioning. Complementary for skin and joint health.
Biotin supports keratin production (hair and nails). Pairing with collagen covers both the structural protein and the keratin pathway.
Hydroxyproline in collagen can be converted to oxalate. For most people this is insignificant; those with calcium oxalate kidney stones may want to monitor.
Safety & side effects
Generally very safe. Most common complaint: taste/texture of powder in drinks (choose flavoured if this bothers you). Mild GI discomfort rare. Those with fish, shellfish, or beef allergies should choose their source accordingly. Contains hydroxyproline which can elevate urinary oxalate — those prone to kidney stones may wish to moderate intake.
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This information is for educational purposes only and does not constitute medical advice. Always consult your GP or a qualified healthcare professional before starting any new supplement, particularly if you are pregnant, breastfeeding, have a medical condition, or are taking prescription medication.