Key Term
The Slow Aging Guide
What the science actually says about living longer
The internet is full of longevity claims—from $1000/day biohacking protocols to "this one weird trick" supplements. Most of it is nonsense. This guide cuts through the noise to focus on what actually works in 2025, what's promising but unproven, and what's pure hype. No products to sell. Just the evidence.
The honest truth about longevity
The 12 Hallmarks of Aging
Scientists have identified 12 biological processes that drive aging. Click each hallmark to learn what it is and how to potentially address it.
Cause cellular damage
Based on López-Otín et al., “Hallmarks of aging: An expanding universe” Cell (2023)
Find Your Longevity Path
Longevity interventions work best when built on a solid lifestyle foundation. Tell us where you are.
Your Options
There's no single right path. Choose based on your situation, and know that you can combine approaches.
Tier 1: Strong Evidence
These interventions have robust evidence from large human studies showing they extend lifespan, delay disease, or improve healthspan. They're not glamorous, but they work. The good news: these are mostly free or cheap. The challenge: they require consistent effort over decades.
- Cardiorespiratory fitness (VO₂ max is the strongest predictor of all-cause mortality)
- Resistance training (prevents sarcopenia, maintains independence)
- Sleep optimization (7-8 hours, consistent timing, good quality)
- Not smoking (still the single biggest modifiable risk factor)
- Moderate alcohol or none (the "healthy glass of wine" data has been debunked)
- Maintaining healthy weight (especially avoiding central obesity)
- Social connection (loneliness rivals smoking for mortality risk)
- Thinking supplements can replace these fundamentals
- Extreme interventions before mastering the basics
- Pursuing "biohacks" that lack human evidence
- Ignoring mental health and stress management
Tier 2: Promising Evidence
These interventions have solid mechanistic rationale and encouraging human data, but we don't yet have definitive proof they extend lifespan. Many are actively being studied. Some of these may graduate to Tier 1 as more data comes in. Others may not pan out.
- Heat therapy (sauna: 4x/week associated with 40% lower all-cause mortality)
- Time-restricted eating (may improve metabolic health, unclear on lifespan)
- Cold exposure (dopamine, mood, inflammation—but hypertrophy concerns)
- Zone 2 cardio emphasis (mitochondrial benefits, sustainable long-term)
- Protein optimization (1.2-1.6g/kg, especially for muscle preservation)
- Mediterranean diet pattern (consistent disease reduction data)
- Extreme fasting without medical supervision
- Assuming "promising" means "proven"
- Neglecting Tier 1 while chasing Tier 2
- Ignoring individual response variation
Tier 3: Speculative
These interventions work in animals or have limited human data. They're exciting for researchers but shouldn't be considered "anti-aging" interventions for regular people—yet. Some longevity enthusiasts experiment with these, but they're accepting real risks in exchange for uncertain benefits.
- Understand the evidence before trying anything
- Work with a doctor who understands these interventions
- Track your biomarkers if experimenting
- Be honest about risk/benefit tradeoffs
- Taking rapamycin without medical supervision
- Buying peptides from unverified sources
- Assuming mouse data translates to humans
- Spending significant money on unproven interventions
- Treating supplements as safe just because they're "natural"
Your Toolkit
Exercise: The Single Biggest Lever
Sleep: When You Actually Repair
Heat & Cold Therapy
Nutrition: Evidence Over Ideology
Speculative Interventions (Tier 3)
Daily Routine
Light + movement
Get outside within an hour of waking—morning light anchors your circadian rhythm. Even 10-15 minutes helps. Add a 10-minute walk if possible.
First eating window
If doing time-restricted eating, start here rather than immediately upon waking. Protein-forward breakfast to start your eating window strong.
Movement break + Zone 2
Walk after lunch (improves blood sugar). If possible, this is a great time for Zone 2 cardio—30-60 minutes at conversation pace.
Resistance training (if scheduled)
2-3 sessions per week, 30-45 minutes each. Full body or upper/lower split. Progressive overload is key. Don't skip this.
Last meal + wind-down
Finish eating 2-3 hours before bed. Dim lights after sunset. This is when sauna fits well if you have access—relaxes you for sleep.
Sleep optimization
Cool, dark room. Consistent bedtime. No screens 1 hour before (or use night mode). Aim for 7-8 hours of actual sleep, not just time in bed.
What Longevity Interventions Cost
Good news: the most effective interventions are cheap or free. The expensive stuff often has the weakest evidence.
The Free Tier (Tier 1 evidence)
Walking, bodyweight exercise, sleep optimization, not smoking, social connection, sunlight exposure
Pros
- Strongest evidence for lifespan extension
- Improves quality of life immediately
- No side effects when done properly
- Sustainable for life
Cons
- Requires consistent effort over decades
- Not glamorous or exciting
- Results take time to manifest
The Affordable Tier
Gym membership, sauna access, basic supplements (vitamin D, omega-3, creatine), quality food
Pros
- Good evidence for most items
- Sustainable for most budgets
- Synergistic with free tier interventions
Cons
- Sauna access can be limited
- Supplement quality varies
- Food quality costs more than processed alternatives
The Enthusiast Tier
Regular blood work, home sauna, cold plunge, NAD+ precursors, advanced testing
Pros
- Better data on your health status
- Convenient access to therapies
- May provide marginal additional benefits
Cons
- Diminishing returns vs. lower tiers
- Many supplements lack strong evidence
- Testing without action is pointless
The Experimental Tier
Physician-supervised rapamycin, peptides, senolytics, comprehensive hormone optimization, advanced diagnostics
Pros
- Access to cutting-edge interventions
- Medical supervision reduces risk
- May provide benefits we don't yet understand
Cons
- Weakest evidence tier
- Real risks with uncertain benefits
- Very expensive for unproven outcomes
- The money might be better spent on Tier 1
Ways to Save Money
- Master the free tier before spending money—it has the strongest evidence
- A $30/month gym membership outperforms most supplements
- Community center or YMCA often have sauna access for less than boutique gyms
- Buying frozen vegetables is as nutritious as fresh and much cheaper
- Walking is free and one of the best longevity interventions we have
Insurance strategies, savings programs, telehealth options, and compounding explained.
Troubleshooting
Tap an issue to see the fix.
Deep Dives
Common Questions
Ready to Start?
Pick your entry point based on where you are now.
🌿 Starting with Lifestyle Changes
Start with the fundamentals
Before anything else, nail the big three: consistent exercise, 7-8 hours of sleep, and daily movement. These outperform any supplement or drug.
See Daily RoutineLearn about sauna benefits
Regular sauna use is one of the few heat therapies with strong longevity evidence. Learn the protocols backed by research.
Read Sauna GuideUnderstand cold exposure
Cold plunges have real benefits—but also real trade-offs. Know the evidence before jumping in.
Read Cold Guide💊 Exploring Medication Options
Explore GLP-1 medications
Weight loss is a powerful longevity intervention. If you have significant weight to lose, these medications are worth understanding.
Weight Loss GuideUnderstand the evidence hierarchy
Before experimenting with rapamycin, metformin, or senolytics, understand what level of evidence supports each intervention.
Read Evidence GuideFor Everyone
Glossary
- Healthspan
- The years of life lived in good health, free from chronic disease and disability. For many people, this matters more than total lifespan.
- VO₂ max
- Maximum oxygen consumption—a measure of cardiorespiratory fitness. The strongest predictor of all-cause mortality in the scientific literature.
- Hallmarks of aging
- The 12 biological processes identified as fundamental drivers of aging: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, disabled macroautophagy, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, chronic inflammation, and dysbiosis.
- Cellular senescence
- When cells stop dividing but don't die. They become "zombie cells" that secrete inflammatory signals damaging nearby tissue. Accumulation of senescent cells is a hallmark of aging.
- Senolytics
- Drugs that selectively kill senescent cells. Examples include dasatinib + quercetin (D+Q) and fisetin. Still experimental for longevity use.
- Sarcopenia
- Age-related loss of muscle mass and function. A major driver of frailty and loss of independence. Preventable with resistance training and adequate protein.
- mTOR
- Mechanistic target of rapamycin—a cellular nutrient sensor. When suppressed (by fasting or rapamycin), it activates autophagy and other repair processes. Overactivation is associated with aging.
- Autophagy
- Cellular cleanup process where damaged proteins and organelles are recycled. Activated by fasting, exercise, and certain compounds like rapamycin. Declines with age.
- Zone 2 cardio
- Aerobic exercise at moderate intensity where you can still hold a conversation. Builds mitochondrial density and fat oxidation capacity. The foundation of cardiovascular fitness.
- Epigenetic clock
- A biochemical test that estimates biological age by measuring DNA methylation patterns. Examples include Horvath Clock, GrimAge, and DunedinPACE. Research tools with individual limitations.
- Inflammaging
- Chronic, low-grade inflammation that develops with age. Contributes to most age-related diseases. Can be measured via markers like CRP and IL-6.