Legacy AI grade · Sources dated 2026-06-08. Not expert reviewed. Coverage is limited to the listed sources. About the new summary workflow
Collagen Peptides for Hair Loss
Verdict: Insufficient Evidence
Across 3 PubMed studies, the evidence for Collagen Peptides in Hair Loss grades Tier U — unverified / insufficient. Research is still too limited to draw a firm conclusion.
U ⚫ U Unverified Insufficient Evidence
Why this grade7-layer evidence engine
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Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.43
D
C
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← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
U · Insufficient Evidence
Confidence
65%
Broadly consistent
Evidence level
E6
Multiple smaller RCTs (n<500)
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.43
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 無高階證據可裁決
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 1 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (3)L2 · primary research & systematic reviews
Efficacy and tolerability of an oral supplement containing amino acids, iron, selenium, and marine hydrolyzed collagen in subjects with hair loss
Finding: Group A (supplement + standard) showed significantly higher GAS than Group B (standard alone) at week 12: 1.67 ± 0.16 vs 0.66 ± 0.20, p<0.001. Responders (GAS ≥2): 50% Group A vs 23% Group B. Well tolerated.
View on PubMed Effect of a Hydrolyzed Collagen, Vitamin, and Zinc Containing Nutritional Supplement on Telogen Effluvium
Finding: Significant improvements in all hair parameters at T1 and T2 (p<0.001). Pull test showed reduced shedding sustained during washout. Mild side effects in 10 patients.
View on PubMed Oral supplementation with specific bioactive collagen peptides improves nail growth and reduces symptoms of brittle nails (Hexsel et al.)
Finding: 12% increase in nail growth rate; 42% decrease in broken-nail frequency; 64% global improvement during treatment, 88% at 4 weeks post-treatment.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Supportive
COLLAGEN — CAS Reg. No. 9007-34-5; Other Names: COLLAGENS, ATELOCOLLAGEN; Permitted Technical Effects: FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, SOLVENT OR VEHICLE. source↗
L4b EU EFSA
Against
a cause and effect relationship has not been established between the consumption of collagen hydrolysate and maintenance of joints source↗
L4d TW TFDA / 衛福部
Cautious
膠原蛋白為人體本身就可自行合成之物質……（口服）經過消化作用，變成小分子的胺基酸，未必能在體內重新合成膠原蛋白；（塗抹式）僅可能達到表面保濕、潤澤肌膚的效果，無法吸收再利用。 source↗