# NDGA (Nordihydroguaiaretic Acid) - Clinical Longevity Review & Consensus Audit

> **Consensus Verdict**: NIH Interventions Testing Program (ITP) verified reproducible male rodent lifespan extension.

## 1. Executive Summary & Scores
- **Longevity Evidence Score**: **79/100**
- **Evidence Quality Tier**: **bronze**
- **Human Clinical Evidence Strength**: 71/100
- **Primary Longevity Classification**: supplements
- **Safety Margin Score**: 84/100 (Higher is safer)
- **Time Burden**: ~15 minutes/day
- **Estimated Monthly Cost**: inexpensive
- **Adherence Friction**: 3/10 (Lower is easier to sustain)

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## 2. Biological Mechanisms of Action
5-lipoxygenase (5-LOX) enzymatic inhibition & ROS scavenging

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## 3. Canonical Longevity Vector Impacts (The 8 Longevity Pillars)

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## 4. Practical Protocol & Administration Guidelines
- **Standard Clinical Dosage**: 50 mg
- **Recommended Timing**: Bedtime
- **Administration Type**: supplement
- **Recommended Biomarkers to Monitor**: cellular_longevity, chronic_inflammation

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## 5. Safety, Contraindications & Drug Interactions
- **Contraindications**: Active hepatic dysfunction / liver disease
- **Safety Profile**: Moderate - Keep doses low (50 mg) and monitor liver enzymes (ALT/AST) periodically.

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## 6. Peer-Reviewed Human Clinical Trials & Key PMIDs
1. **Nordihydroguaiaretic Acid (NDGA) Extends Lifespan in Male Mice** [PMID: 18625000]
   - Link: https://pubmed.ncbi.nlm.nih.gov/18625000/
2. **NDGA Inactivates 5-Lipoxygenase and Suppresses Leukotriene B4** [PMID: 24245565]
   - Link: https://pubmed.ncbi.nlm.nih.gov/24245565/
3. **Nordihydroguaiaretic Acid and Aspirin Increase Lifespan in Genetically Heterogeneous Mice: The NIA ITP Experience** [PMID: 18752631]
   - Link: https://pubmed.ncbi.nlm.nih.gov/18752631/

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## 7. Canonical Citation & Web Verification
- **Official Web Review**: [NDGA (Nordihydroguaiaretic Acid) on LongevityReviews](https://longevityreviews.org/modalities/ndga)
- **Last Evidence Calibration**: 2026-08-09
- **Review Policy**: 0% sponsored placements, independent peer-reviewed consensus.