{
  "dataset": "spermidine-cost-by-brand",
  "title": "Spermidine Supplements Compared — cost per actual mg of spermidine, not wheat-germ-extract weight",
  "sourcePage": "https://verifiedsupplementdata.com/spermidine/best-overall/",
  "license": "CC-BY-4.0",
  "licenseUrl": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "Verified Supplement Data (2026), Spermidine Cost Comparison",
  "dateModified": "2026-07-18",
  "methodology": "Spermidine is well under 1% of wheat germ by weight, so a \"1500mg wheat germ extract\" label figure is not a spermidine dose. Only products that disclose an ACTUAL spermidine mg per serving (Double Wood, a synthetic 3HCL product; Longevity Labs spermidineLIFE, which discloses both the extract weight and the spermidine mg it yields) can be ranked by costPerActualMg = price / (servings x disclosed actual spermidine mg). Nutricost and HUMANX do not reliably disclose actual spermidine mg — Nutricost's front-label \"equivalent of 15% spermidine\" claim (~225mg from 1500mg extract) is flagged as implausible against wheat germ's <1% natural spermidine content and against the product's own ingredient-panel listing of \"1% Spermidine\" for the same extract; HUMANX discloses no spermidine figure at all. For both, costPerActualMg is null — UNKNOWABLE from the label, not merely omitted. \"verdict\" tags disclosed products against the human trial dose range: trial-adjacent (close to 0.9-1.2 mg/day), above-trial-dose (well above it — more has never been shown stronger in a human trial), or undisclosed. EVIDENCE CONTEXT (human RCTs only; autophagy induction itself has never been measured as a supplementation outcome in any human trial here): Kiechl 2018 (PMID 29955838, Bruneck cohort, n=829, 20yr) found an OBSERVATIONAL association between higher dietary spermidine intake and lower all-cause mortality (HR 0.76 per 1-SD) — not a supplementation-causes-benefit claim. Schwarz 2022/SmartAge (PMID 35616942, RCT n=100, 12mo, 0.9mg/day) found the PRIMARY memory endpoint NULL — the essential honest counterweight, always named before any secondary finding. Wirth 2018 (PMID 30388439, pilot RCT n=30, 3mo, 1.2mg/day) found a positive memory signal (d=.77) that SmartAge was built to confirm and did not, on its primary endpoint. Keohane 2024 (PMID 39405978, RCT n=37, 40mg/day, 28 days) is SAFETY/pharmacokinetic data only — no efficacy endpoint, and circulating spermidine barely moved. No cancer-mortality claim is made or supported; no precise dietary mg/day figure is asserted (both excluded as unverifiable). This statement has not been evaluated by the FDA; these products are not intended to diagnose, treat, cure, or prevent any disease.",
  "headline": {
    "productsCompared": 4,
    "disclosed": 2,
    "undisclosed": 2,
    "trialLowMg": 0.9,
    "trialHighMg": 1.2,
    "safetyTestedMg": 40,
    "cheapestPerActualMg": 0.0663,
    "cheapestPerActualMgBrand": "Double Wood",
    "trialAdjacentBrand": "Longevity Labs",
    "note": "Ranked by disclosed actual spermidine mg FIRST, then cost per actual mg — never by wheat-germ-extract weight or commissions. Two of four tracked products do not reliably disclose actual spermidine mg."
  },
  "columns": [
    "brand",
    "product",
    "slug",
    "form",
    "labelMgPerServing",
    "actualSpermidineMgPerServing",
    "servings",
    "price",
    "costPerServing",
    "costPerActualMg",
    "verdict",
    "thirdParty"
  ],
  "units": {
    "labelMgPerServing": "mg wheat-germ-extract or synthetic dose",
    "actualSpermidineMgPerServing": "mg spermidine (disclosed)",
    "price": "USD",
    "costPerServing": "USD/serving",
    "costPerActualMg": "USD per mg of actual spermidine"
  },
  "citations": [
    {
      "claim": "Bruneck cohort, n=829, 20yr follow-up: all-cause mortality HR 0.76 (95% CI 0.67-0.86) per 1-SD higher DIETARY spermidine intake; top-vs-bottom tertile roughly \"5.7 years younger.\" Observational — confounded by overall diet quality, never a supplementation claim.",
      "source": "Kiechl S, et al. 2018, Am J Clin Nutr",
      "pmid": "29955838"
    },
    {
      "claim": "RCT n=100, 12 months, 0.9mg/day (SmartAge): PRIMARY memory endpoint NULL (diff -0.03, 95% CI -0.11 to 0.05, p=.47). Secondary verbal-memory/inflammation findings are exploratory only.",
      "source": "Schwarz C, et al. 2022, JAMA Netw Open",
      "pmid": "35616942"
    },
    {
      "claim": "Pilot RCT n=30, 3 months, 1.2mg/day, older adults with subjective cognitive decline: memory (mnemonic discrimination) improved, Cohen's d=.77. Tiny pilot; SmartAge was built to confirm it and did not, on the primary endpoint.",
      "source": "Wirth M, et al. 2018, Cortex",
      "pmid": "30388439"
    },
    {
      "claim": "Safety companion to Wirth (same n=30 cohort): no adverse events, excellent tolerability. Same trial, not an independent replication.",
      "source": "Schwarz C, et al. 2018, Aging",
      "pmid": "29315079"
    },
    {
      "claim": "RCT n=37 men, 40mg/day high-purity spermidine, 28 days: no safety signal, but circulating polyamines barely changed (bioavailability caveat). Safety/PK only, no efficacy endpoint — never an \"effective dose.\"",
      "source": "Keohane DM, et al. 2024, Nutrition Research",
      "pmid": "39405978"
    },
    {
      "claim": "Review of observational cognition literature: MIXED — some cohorts show higher spermidine intake associated with WORSE outcomes; measurement inconsistent; blood-brain-barrier crossing uncertain.",
      "source": "Yu H, et al. 2025, General Psychiatry",
      "pmid": "41098596"
    }
  ],
  "products": [
    {
      "brand": "Double Wood",
      "product": "Spermidine 10mg (99% Spermidine 3HCL)",
      "slug": "double-wood-spermidine-10mg",
      "form": "Capsule",
      "labelMgPerServing": 10,
      "actualSpermidineMgPerServing": 10,
      "servings": 60,
      "price": 39.75,
      "costPerServing": 0.66,
      "costPerActualMg": 0.0663,
      "verdict": "above-trial-dose",
      "thirdParty": "Third-party HPLC-tested per batch"
    },
    {
      "brand": "Longevity Labs",
      "product": "spermidineLIFE (CelVio Wheat Germ Extract)",
      "slug": "longevity-labs-spermidinelife",
      "form": "Capsule",
      "labelMgPerServing": 800,
      "actualSpermidineMgPerServing": 1,
      "servings": 30,
      "price": 69,
      "costPerServing": 2.3,
      "costPerActualMg": 2.3,
      "verdict": "trial-adjacent",
      "thirdParty": "CelVio-branded wheat germ extract (EFSA novel-food approved); discloses both extract mg and actual spermidine mg"
    },
    {
      "brand": "Nutricost",
      "product": "Spermidine Wheat Germ",
      "slug": "nutricost-spermidine-wheat-germ",
      "form": "Capsule",
      "labelMgPerServing": 1500,
      "actualSpermidineMgPerServing": null,
      "servings": 40,
      "price": 44.95,
      "costPerServing": 1.12,
      "costPerActualMg": null,
      "verdict": "undisclosed",
      "thirdParty": "GMP-compliant, ISO-accredited lab testing (identity/purity — not an independently verified spermidine-mg assay)"
    },
    {
      "brand": "HUMANX",
      "product": "Spermidine+ (Wheat Germ Extract + Zinc/Thiamine)",
      "slug": "humanx-spermidine-plus",
      "form": "Capsule",
      "labelMgPerServing": 998,
      "actualSpermidineMgPerServing": null,
      "servings": 30,
      "price": 49.95,
      "costPerServing": 1.67,
      "costPerActualMg": null,
      "verdict": "undisclosed",
      "thirdParty": "Third-party tested (purity claim only — not an independently verified spermidine-mg assay)"
    }
  ]
}