Rankings / Longevity — Senolytics & Polyphenols
Spermidine
Longevity · Polyamine (autophagy inducer)
Tier B+
Bottom line
Read Off Label grades Spermidine as B+ (7.1/10) based on moderate evidence, moderate benefit magnitude, and a low-risk safety profile.
Kiechl 2018: higher dietary spermidine associated with reduced all-cause mortality in Austrian Bruneck cohort.
Typical use: 1-3 mg/day (dietary 7-10 mg from wheat germ, aged cheese, natto) — OTC.
What this is
Kiechl 2018: higher dietary spermidine associated with reduced all-cause mortality in Austrian Bruneck cohort. POLYCAD trial in elderly CAD patients results expected 2026. Strongest human observational data among the "autophagy inducers." A 2026 pilot RCT (Aging Cell, n=40 adults >65; spermidine 6 mg/day x 13 wk) enhanced SARS-CoV-2 vaccine responses — spike-specific IgG, memory B-cell recall, neutralizing antibodies — in prior non-responders, and reversed immunosenescence markers (p16, mTOR signaling, lymphocyte DNA damage). Pilot-scale; tier unchanged.
Mechanism
Natural polyamine; induces autophagy via direct activation; eIF5A hypusination cofactor; mitochondrial biogenesis; reduced protein aggregation
Dose & route
1-3 mg/day (dietary 7-10 mg from wheat germ, aged cheese, natto)
Citations
- https://academic.oup.com/ajcn/article/108/2/371/5086535
- https://www.nature.com/articles/s41591-016-0017-4
- https://link.springer.com/article/10.1186/s13063-025-09176-z
- https://pubmed.ncbi.nlm.nih.gov/42086115/
- https://pubmed.ncbi.nlm.nih.gov/41799286/
- https://doi.org/10.23876/j.krcp.25.413
- https://doi.org/10.1111/acel.70545
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Common questions
- Does Spermidine work?
- Read Off Label rates the evidence for Spermidine as Moderate and the benefit magnitude as moderate, producing an overall grade of B+ (7.1/10). Kiechl 2018: higher dietary spermidine associated with reduced all-cause mortality in Austrian Bruneck cohort.
- Is Spermidine safe?
- Spermidine has a low risk profile in published human data. Legal status: OTC (wheat germ extract; synthetic). This is not medical advice — see the disclaimer.
- What is the typical dose for Spermidine?
- 1-3 mg/day (dietary 7-10 mg from wheat germ, aged cheese, natto)
- How does Spermidine work?
- Natural polyamine; induces autophagy via direct activation; eIF5A hypusination cofactor; mitochondrial biogenesis; reduced protein aggregation
This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.