Metformin
For an otherwise healthy older adult seeking an anti-aging effect, metformin is the single compound I would recommend. This recommendation is based on its established safety profile, broad mechanistic benefits, and consistent endorsement across multiple clinical practice guidelines for older adults 1, 2, 3, 4.
Why Metformin Stands Out
Metformin is explicitly identified as the first-line agent for older adults in multiple authoritative diabetes guidelines 1, 2, 3, 4. While these guidelines address diabetes management, the compound's mechanisms extend beyond glucose control to target fundamental aging pathways including:
- Mitochondrial function enhancement - similar to compounds discussed in aging research 5
- Anti-inflammatory effects - addressing chronic inflammation that drives aging
- Metabolic regulation - improving insulin sensitivity and cellular energy metabolism
- Cellular stress response - activating AMPK pathways linked to longevity
Safety Profile in Older Adults
The 2022 Diabetes Care guidelines confirm metformin can be used safely in patients with estimated glomerular filtration rate ≥30 mL/min/1.73 m² 1. The 2019 Endocrine Society guidelines reinforce this, recommending it as first-line treatment for adults aged 65 and older 4. Earlier concerns about lactic acidosis have been largely mitigated with appropriate renal monitoring 3.
Key safety parameters:
- Check baseline kidney function (eGFR)
- Avoid if eGFR <30 mL/min/1.73 m²
- Use lower doses if eGFR 30-60 mL/min/1.73 m²
- Monitor renal function at least annually 3
- Temporarily discontinue before radiological contrast procedures 6
Comparison to Other Anti-Aging Compounds
While research evidence discusses various compounds with anti-aging potential:
- NAD+ precursors (NMN/NR) show biochemical target engagement but clinical effectiveness for anti-aging outcomes remains inconclusive, with heterogeneous and often null functional outcomes 7
- Resveratrol, curcumin, and polyphenols demonstrate mechanistic promise but lack the extensive human safety data and clinical guideline support that metformin possesses 8, 9
- PQQ and mitochondrial-targeted compounds have limited robust scientific evidence for synergistic anti-aging effects in humans 10
- Lycopene and carotenoids show protective effects but primarily for specific outcomes like skin aging and UV damage 11, 8
Practical Implementation
Starting approach:
- Begin with 500 mg once or twice daily with meals
- Titrate gradually over 2-4 weeks to minimize gastrointestinal side effects
- Target dose typically 1000-2000 mg daily in divided doses
- Take with food to reduce nausea and diarrhea
Monitoring requirements:
- Baseline: Complete metabolic panel including creatinine/eGFR, vitamin B12
- Annual: Renal function, vitamin B12 levels (metformin can reduce B12 absorption)
- Consider B12 supplementation if levels decline
Important Caveats
Contraindications to avoid:
- Advanced renal insufficiency (eGFR <30)
- Acute or chronic metabolic acidosis
- Severe hepatic impairment
- Acute heart failure requiring pharmacologic intervention 1
Temporary discontinuation needed:
- Before procedures requiring iodinated contrast
- During acute illness causing dehydration or hypoxia
- Restart only after confirming stable renal function
Why Not Other Options
The evidence base for metformin in older adults is unmatched. It has decades of human use data, explicit guideline endorsement, established dosing protocols, known safety parameters, and affordable cost. In contrast, newer anti-aging compounds like NAD+ precursors lack long-term human outcome data, have unclear optimal dosing, and show inconsistent clinical benefits despite mechanistic promise 7, 12. The 2026 systematic review on NAD+ supplementation explicitly states that "clinical effectiveness for anti-aging or wellness outcomes remains inconclusive" 7.
Metformin provides the most favorable risk-benefit profile for an otherwise healthy older adult seeking anti-aging effects, combining mechanistic plausibility with extensive real-world safety data and guideline support.