{
  "dataset": "collagen-types-comparison",
  "title": "Collagen Types Compared — Type I, II (undenatured vs hydrolyzed), III, V, X; bovine vs marine vs chicken vs eggshell; peptides vs gelatin vs undenatured",
  "sourcePage": "https://verifiedsupplementdata.com/collagen/types-compared/",
  "license": "CC BY 4.0",
  "licenseUrl": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "Verified Supplement Data (2026), Collagen Types Comparison and Label Census",
  "dateModified": "2026-09-14",
  "methodology": "Type, source and form comparisons summarise randomized trials verified against PubMed (PMIDs listed per row). The label census reads every on-market collagen label filed with the NIH Dietary Supplement Label Database in two populations — the general collagen shelf and every label matching \"type ii collagen\" — and classifies declared type, source and form from the product name, label statements and Supplement Facts ingredient names. Daily dose = collagen row × maximum daily servings. Every published figure was recomputed in both halves of the read order; figures that did not agree within 8 points (shares) or 25% (medians) are not published.",
  "types": [
    {
      "type": "Type I",
      "form": "Hydrolyzed peptides (grams)",
      "source": "Bovine hide; fish skin and scales",
      "soldFor": "Skin, hair, nails, bone",
      "evidence": "Best-supported use. A placebo-controlled trial of 2.5 g or 5 g/day of specific peptides improved skin elasticity in 69 women aged 35–55 over 8 weeks; a 12-week trial of 2.5 g in a blend with vitamin C, zinc and biotin improved hydration, elasticity, roughness and density. Meta-analyses of 19 and 26 RCTs (1,125 and 1,721 participants) confirm modest hydration and elasticity gains; the 2023 analysis flags bias in the included trials. A 12-month RCT of 5 g/day raised spine and femoral-neck bone density in 131 postmenopausal women.",
      "studiedDose": "2.5–10 g/day (skin), 5 g/day (bone)",
      "pmids": [
        "23949208",
        "31627309",
        "33742704",
        "37432180",
        "29337906"
      ],
      "verdict": "The product the skin and bone evidence is about. Bovine hide supplies it with Type III; fish supplies it nearly alone."
    },
    {
      "type": "Type II — undenatured (UC-II)",
      "form": "Native, unhydrolyzed (milligrams)",
      "source": "Chicken sternal cartilage",
      "soldFor": "Joints, knee comfort",
      "evidence": "Works by oral tolerance — the intact triple helix is an immune signal, not a building block. 40 mg/day beat placebo and glucosamine 1,500 mg + chondroitin 1,200 mg on total WOMAC in 191 people with knee osteoarthritis over 180 days, and improved knee extension in healthy adults with activity-related discomfort.",
      "studiedDose": "40 mg/day",
      "pmids": [
        "26822714",
        "19847319",
        "24153020",
        "8378772",
        "12837047"
      ],
      "verdict": "A different product with a different mechanism. Milligrams are the correct dose, not an underdose. Grams of hydrolyzed collagen do not substitute for it."
    },
    {
      "type": "Type II — hydrolyzed",
      "form": "Hydrolyzed peptides (grams)",
      "source": "Chicken cartilage",
      "soldFor": "Joints",
      "evidence": "No trial isolates hydrolyzed Type II. The gram-dose joint trials (10 g/day for 24 weeks in athletes; 5 g/day in physically active adults) used Type I/III-dominant collagen hydrolysate, not Type II.",
      "studiedDose": "5–10 g/day (as generic hydrolysate)",
      "pmids": [
        "18416885",
        "28177710",
        "33562729"
      ],
      "verdict": "Buy it as generic collagen peptides. The \"Type II\" on the label is not what the joint evidence tested."
    },
    {
      "type": "Type III",
      "form": "Hydrolyzed peptides (grams)",
      "source": "Bovine hide, alongside Type I",
      "soldFor": "Skin, gut, blood vessels",
      "evidence": "Arrives with Type I in every bovine-hide hydrolysate; the skin and bone trials above used Type I/III mixtures. No trial isolates Type III or shows it adds anything to Type I.",
      "studiedDose": "Not separately studied",
      "pmids": [
        "23949208",
        "29337906"
      ],
      "verdict": "A word on the label, not a product. \"Type I & III\" and \"Type I\" bovine peptides are the same thing."
    },
    {
      "type": "Type V and Type X",
      "form": "Hydrolyzed, inside \"multi-collagen\" blends",
      "source": "Eggshell membrane (V, X); chicken cartilage (X)",
      "soldFor": "\"All five types\" / \"complete collagen\"",
      "evidence": "No human outcome trial of Type V or Type X as a supplement. They appear in trace amounts inside eggshell-membrane and cartilage ingredients; the blends that list them are, by weight, bovine and fish Type I/III peptides.",
      "studiedDose": "None",
      "pmids": [],
      "verdict": "Marketing. Pay for the grams of Type I/III in the blend, not for the count of types on the front."
    }
  ],
  "sources": [
    {
      "source": "Bovine (hide)",
      "types": "I and III",
      "form": "Hydrolyzed peptides, gelatin",
      "evidence": "The most-studied source: the 2.5–5 g skin trials and the 5 g bone trial used bovine-derived peptides.",
      "practical": "Cheapest per gram; not suitable for pescatarians, kosher/halal buyers need a certified product.",
      "pmids": [
        "23949208",
        "29337906"
      ]
    },
    {
      "source": "Marine (fish skin, scales)",
      "types": "Mostly I",
      "form": "Hydrolyzed, often low molecular weight",
      "evidence": "Positive skin RCT at 1 g/day of a low-molecular-weight fish peptide over 12 weeks in 64 people. In a 5-man crossover, fish-scale hydrolysate produced more hydroxyproline peptides in blood than porcine skin — a pharmacokinetic signal, not an outcome, and bovine was not tested. The 26-trial meta-analysis found no significant difference between collagen sources on skin elasticity (p = 0.21). No head-to-head outcome trial against bovine exists; the 2025 marine-collagen review is a narrative summary of mostly preclinical (cell and animal) work, not human trial evidence.",
      "practical": "Fish allergy excludes it; pescatarian-compatible; usually costs more per gram; heavy-metal testing matters more here.",
      "pmids": [
        "29949889",
        "17253720",
        "37432180",
        "41393269"
      ]
    },
    {
      "source": "Chicken (sternal cartilage)",
      "types": "II",
      "form": "Undenatured (UC-II) or hydrolyzed",
      "evidence": "The only source of the undenatured Type II used in the 40 mg knee-osteoarthritis trials.",
      "practical": "Buy it undenatured and in milligrams; hydrolyzed chicken collagen is a generic peptide.",
      "pmids": [
        "26822714",
        "19847319"
      ]
    },
    {
      "source": "Eggshell membrane",
      "types": "I, V, X (with elastin, hyaluronic acid)",
      "form": "Whole membrane powder",
      "evidence": "A different ingredient with its own small trials at 500 mg/day for joint pain and stiffness; it is not a collagen peptide supplement.",
      "practical": "Egg allergy excludes it. Its presence is what lets a blend print \"Type V and X\".",
      "pmids": [
        "19554094"
      ]
    }
  ],
  "forms": [
    {
      "form": "Hydrolyzed collagen / collagen peptides",
      "what": "Collagen broken by enzymes into short peptides (typically under 3,000 Da) that dissolve in cold water.",
      "evidence": "The form in every skin, bone and body-composition trial. Specific peptides (Pro-Hyp, Hyp-Gly) are detectable in blood after ingestion; a further enzymatic hydrolysis step raised the absorption rate of glycine, proline and hydroxyproline in a 10-man crossover.",
      "pmids": [
        "16076145",
        "25212331",
        "39149544",
        "31086034"
      ]
    },
    {
      "form": "Gelatin",
      "what": "Partially hydrolyzed collagen that gels when cooled; the same amino acids in longer chains.",
      "evidence": "In an 8-man crossover, 15 g of vitamin-C-enriched gelatin taken an hour before six minutes of rope-skipping doubled the blood marker of collagen-I synthesis (P1NP). A mechanism study for tendon and ligament, not the evidence base peptides have for skin.",
      "pmids": [
        "27852613"
      ]
    },
    {
      "form": "Undenatured (native) Type II",
      "what": "Collagen kept in its folded triple-helix shape by low-temperature processing.",
      "evidence": "Acts through oral tolerance in gut-associated immune tissue — the mechanism first shown with oral Type II collagen in rheumatoid arthritis. Dosed at 40 mg because it is a signal, not a nutrient.",
      "pmids": [
        "8378772",
        "12837047",
        "26822714"
      ]
    },
    {
      "form": "\"Molecular weight\" claims (e.g. 2,000 Da, 500 Da)",
      "what": "Peptide size printed on the label.",
      "evidence": "Trials used low-molecular-weight hydrolysates, and brand-specific \"bioactive collagen peptide\" products ran their own trials. No study shows that a lower stated Dalton number predicts a better outcome.",
      "pmids": [
        "29949889",
        "31086034"
      ]
    }
  ],
  "labelCensus": {
    "source": "NIH Dietary Supplement Label Database (DSLD) v9",
    "sourceUrl": "https://dsld.od.nih.gov/",
    "retrievedOn": "2026-09-14",
    "onMarket": 46040,
    "labelsRead": 851,
    "shelfPopulation": 746,
    "typeIISearchPopulation": 105,
    "withDose": 611,
    "findings": {
      "declaresAnyTypePct": 43.2,
      "typeShareOfTypedPct": {
        "1": 86.3,
        "2": 44.7,
        "3": 77.3,
        "5": 18,
        "10": 17.1
      },
      "typeIILabels": 247,
      "undenaturedTypeIIMedianMgPerDay": 40,
      "hydrolyzedTypeIIMedianMgPerDay": 2000,
      "multiCollagenPct": 12.3,
      "multiCollagenLabels": 92,
      "multiCollagenUndenaturedTypeIIPct": 2.2,
      "sourceDeclaredPct": 89,
      "sourceShareOfDeclaredPct": {
        "bovine": 72,
        "marine": 61,
        "chicken": 24.4,
        "eggshell": 16.4,
        "porcine": 1.5
      },
      "medianMgPerDayBySource": {
        "bovine": 11000,
        "marine": 5000
      },
      "vitaminCPairedPct": 30,
      "hyaluronicAcidPairedPct": 17.4,
      "formSharePct": {
        "hydrolyzed": 84,
        "undenatured": 1.7,
        "gelatin": 0,
        "unstated": 14.2
      }
    },
    "validation": {
      "method": "split-half by DSLD read order",
      "checked": [
        "fewer than half of labels declare a type",
        "Type I is the most-declared type",
        "UC-II daily dose (median mg)",
        "hydrolyzed Type II daily dose (median mg)",
        "multi-collagen share of shelf",
        "multi-collagen = bovine+chicken+marine blends",
        "bovine is the most-declared source",
        "vitamin C co-formulated share",
        "source declared share",
        "Type III share of typed labels",
        "Type II share of typed labels",
        "Type V share of typed labels",
        "Type X share of typed labels",
        "undenatured share of Type II labels",
        "undenatured share of multi-type Type II labels",
        "multi-collagen daily dose (median mg)",
        "marine share of source-declaring labels",
        "chicken share of source-declaring labels",
        "eggshell share of source-declaring labels",
        "bovine-only daily dose (median mg)",
        "marine-only daily dose (median mg)",
        "chicken-only daily dose (median mg)",
        "hyaluronic acid co-formulated share",
        "hydrolyzed/peptide form share",
        "undenatured form share",
        "form unstated share"
      ],
      "held_in_both_halves": [
        "fewer than half of labels declare a type",
        "Type I is the most-declared type",
        "UC-II daily dose (median mg)",
        "multi-collagen share of shelf",
        "bovine is the most-declared source",
        "vitamin C co-formulated share",
        "source declared share",
        "Type III share of typed labels",
        "Type II share of typed labels",
        "Type V share of typed labels",
        "Type X share of typed labels",
        "undenatured share of multi-type Type II labels",
        "marine share of source-declaring labels",
        "chicken share of source-declaring labels",
        "eggshell share of source-declaring labels",
        "bovine-only daily dose (median mg)",
        "marine-only daily dose (median mg)",
        "hyaluronic acid co-formulated share",
        "hydrolyzed/peptide form share",
        "undenatured form share",
        "form unstated share",
        "hydrolyzed Type II daily dose (median mg)"
      ],
      "failed": [
        "multi-collagen = bovine+chicken+marine blends",
        "multi-collagen daily dose (median mg)",
        "chicken-only daily dose (median mg)",
        "undenatured share of Type II labels"
      ],
      "n": 746,
      "detail": {
        "fewer than half of labels declare a type": {
          "half_a": 41.6,
          "half_b": 44.8,
          "holds": true
        },
        "Type I is the most-declared type": {
          "half_a": 85.2,
          "half_b": 87.4,
          "holds": true
        },
        "UC-II daily dose (median mg)": {
          "half_a": 40,
          "half_b": 40,
          "holds": true
        },
        "hydrolyzed Type II daily dose (median mg)": {
          "half_a": 2000,
          "half_b": 2000,
          "holds": true
        },
        "multi-collagen share of shelf": {
          "half_a": 12.1,
          "half_b": 12.6,
          "holds": true
        },
        "multi-collagen = bovine+chicken+marine blends": {
          "half_a": 73.3,
          "half_b": 61.7,
          "holds": false
        },
        "bovine is the most-declared source": {
          "half_a": 73.7,
          "half_b": 70.3,
          "holds": true
        },
        "vitamin C co-formulated share": {
          "half_a": 29.5,
          "half_b": 30.6,
          "holds": true
        },
        "source declared share": {
          "half_a": 89.5,
          "half_b": 88.5,
          "holds": true
        },
        "Type III share of typed labels": {
          "half_a": 78.7,
          "half_b": 76,
          "holds": true
        },
        "Type II share of typed labels": {
          "half_a": 45.2,
          "half_b": 44.3,
          "holds": true
        },
        "Type V share of typed labels": {
          "half_a": 20.6,
          "half_b": 15.6,
          "holds": true
        },
        "Type X share of typed labels": {
          "half_a": 20,
          "half_b": 14.4,
          "holds": true
        },
        "undenatured share of Type II labels": {
          "half_a": 9.1,
          "half_b": 43.5,
          "holds": false
        },
        "undenatured share of multi-type Type II labels": {
          "half_a": 4.4,
          "half_b": 0,
          "holds": true
        },
        "multi-collagen daily dose (median mg)": {
          "half_a": 2500,
          "half_b": 10000,
          "holds": false
        },
        "marine share of source-declaring labels": {
          "half_a": 60.5,
          "half_b": 61.5,
          "holds": true
        },
        "chicken share of source-declaring labels": {
          "half_a": 24.3,
          "half_b": 24.5,
          "holds": true
        },
        "eggshell share of source-declaring labels": {
          "half_a": 17.7,
          "half_b": 15.2,
          "holds": true
        },
        "bovine-only daily dose (median mg)": {
          "half_a": 11000,
          "half_b": 11000,
          "holds": true
        },
        "marine-only daily dose (median mg)": {
          "half_a": 5000,
          "half_b": 5000,
          "holds": true
        },
        "chicken-only daily dose (median mg)": {
          "half_a": 1000,
          "half_b": 2000,
          "holds": false
        },
        "hyaluronic acid co-formulated share": {
          "half_a": 14.2,
          "half_b": 20.6,
          "holds": true
        },
        "hydrolyzed/peptide form share": {
          "half_a": 86.3,
          "half_b": 81.8,
          "holds": true
        },
        "undenatured form share": {
          "half_a": 2.4,
          "half_b": 1.1,
          "holds": true
        },
        "form unstated share": {
          "half_a": 11.3,
          "half_b": 17.2,
          "holds": true
        }
      },
      "note": "shelf findings split-half within the shelf population; Type II dose findings split-half across both populations"
    }
  }
}