5 Best Biological Age Tests of 2025

October 14, 2025
|
Alina Su

What if your driver's license has your age wrong? Your chronological age is just one part of the story. The real measure of your health and longevity is your biological age. Unlike the years since your birth, biological age reflects how well your cells and organs are functioning. We can measure and reverse it.

The market is flooded with at-home kits, making it hard to distinguish gimmicks from genuine science. The confusion is real: blood versus saliva collection, different biomarkers, varying detail levels, and different price points. Some tests give a single number, while others analyze hundreds of thousands of data points.

To cut through the noise, we spent months researching and testing the best biological age test of 2025. We evaluated them on accuracy, scientific validation, and most importantly, the power to give you actionable health insights. Several tests showed promise, but one stood out for its clinical-grade precision and unprecedented organ-level detail.

The best biological age tests are:

  1. Generation Lab SystemAge: Best Overall
  2. TruDiagnostic: Best for data-driven biohackers
  3. Function Health: Best for general health tracking
  4. Tally Health: Best for convenient swab
  5. GlycanAge: Best for inflammation focus

What is Biological Age?

For anyone serious about their health, understanding the difference between chronological and biological age is crucial. Chronological age is the time since your birth, and it is fixed and unchangeable. Biological age measures the functional age of your cells and organs based on their health and deterioration. Biological age is your health GPS: chronological age tells you where you started, but biological age reveals your current health location.

The science behind this lies in epigenetics, which is the layer of instructions on top of your DNA. While your genetic code remains unchanged, epigenetic patterns shift based on your lifestyle, environment, and age. The primary mechanism driving this is DNA methylation, which acts like biological switches that turn genes on or off. Methylation is your body's control system: over time, "noise" or errors accumulate in these patterns, and this biomolecular noise drives aging and disease risk.

Knowing your biological age is powerful because it's about prevention over treatment. By detecting molecular "noise" early, you can identify health risks years before symptoms. Epigenetic age testing lets you peer into your future health and take action today to change your trajectory. Instead of waiting for disease, optimize your biology while you're still healthy, potentially adding years to your life and life to your years.

Our 5-Point Criteria for the Best Biological Age Test

Not all tests are equal. We developed a 5-point evaluation framework based on what matters for a preventive health testing tool to provide a fair review. Here's how we evaluated each option:

  1. Clinical-Grade Accuracy: How close is the test to the gold standard of laboratory measurement? We looked for peer-reviewed validation, high accuracy percentages, and evidence that the test can reliably detect biological age changes. A test that's 60% accurate isn't much better than guessing.
  2. Comprehensiveness & Resolution: Does the test give you one generic number, or provide deep insights? We prioritized tests that analyze a high number of biomarkers and offer organ-specific aging data. Knowing your heart is aging faster than your brain allows for targeted interventions.
  3. Scientific Validation & Pedigree: Who is behind the test? We sought backing from world-renowned scientists, top-tier research institutions like Harvard and UC Berkeley, and publications in credible journals like Nature and Aging. Science matters, and we wanted tests built on decades of research, not marketing hype.
  4. Actionability: Does the test provide data or actionable recommendations to improve your results? The best test must provide personalized, actionable recommendations. Data without direction is just expensive trivia.
  5. User Experience: How easy is the at-home collection process? We considered the collection method, which includes needle-free blood versus cheek swab, the clarity of the final report and the time to receive results.

The Top 5 Biological Age Tests of 2025 Reviewed

After applying our 5-point criteria, five tests made our final list. We'll count down from number five to reveal our top pick, which is the best biological age test for 2025.

#5. GlycanAge: A Niche Focus on Inflammation

GlycanAge analyzes glycans, which are sugar molecules attached to proteins, to measure immune system age and inflammation levels. For those concerned about chronic inflammation, this test provides valuable insights into this aspect of aging.

Limitations:

  • Limited Scope: Measures only one aspect of aging (inflammation) and misses the full picture across other systems like cardiovascular, neurological, or metabolic health.
  • Lack of Organ Detail: Instead of a comprehensive system-wide analysis, it provides a single "Immune Age" score.
  • Narrow Actionability: Recommendations focus on anti-inflammatory interventions, missing opportunities for targeted improvements in other aging pathways.

Verdict: A useful tool for tracking inflammation, but too narrow to be a comprehensive biological age test. It's like having a thermometer when you need a full physical exam.

#4. Tally Health: The Celebrity-Backed Swab

Tally Health gained attention through co-founder Dr. David Sinclair's celebrity status in the longevity field. The test offers a user-friendly cheek swab collection method that takes minutes to complete at home.

Limitations:

  • Collection Method vs. Accuracy Trade-off: The cheek swab is convenient, but blood-based DNA methylation tests are the gold standard for accuracy and data richness. Saliva samples contain fewer cells and lower DNA concentrations.
  • Limited Resolution: Provides a single, aggregate age score lacking organ-level detail for targeted interventions.
  • Generic Recommendations: Without organ-specific data, the advice is broad lifestyle suggestions rather than precision guidance.

Verdict: Great marketing and a convenient collection method, but it lacks the clinical-grade depth and organ-specific data of advanced tests. It's the difference between a smartphone camera and a professional medical imaging system.

#3. Function Health: Broad, Not Deep

Function Health offers 100+ standard blood biomarkers for a yearly subscription. It provides insights into your current health status across multiple systems for general wellness tracking.

Limitations:

  • Not an Epigenetic Test: This is a conventional blood panel, not an epigenetic age testing kit. It measures current health status rather than the deeper epigenetic signals of aging and future disease risk.
  • Lacks Early Detection Power: It can miss the "biomolecular noise" that signals risk years before it shows up in conventional blood tests by focusing on standard biomarkers.
  • Reactive vs. Predictive: Shows current events, not future predictions based on your aging trajectory.

Verdict: An excellent service for conventional health tracking, but it operates on a different, less predictive level than true epigenetic analysis. It's like checking your speedometer instead of your GPS when planning a long journey.

#2. TruDiagnostic: A Data-Rich Contender

TruDiagnostic is a serious player in the epigenetic testing space. The test analyzes over 900,000 methylation sites and provides biological age estimates for up to 11 organ systems, making it a comprehensive option for data-driven individuals.

Limitations:

  • Accuracy Concerns: It falls short of the precision needed for reliable health decision-making, with 58% validated accuracy compared to clinical-grade standards.
  • Less Comprehensive System Analysis: While 11 organ scores represent good coverage, it's significantly less than the 19 systems analyzed by advanced options.
  • Actionability Gap: The recommendations are more generic compared to systems that provide targeted intervention plans for each measured organ system.
  • Complex Interface: Without clear prioritization of important results, the wealth of data can overwhelm users.

Verdict: A powerful, data-heavy test appealing to biohackers, but it falls short of the number one spot due to lower validated accuracy and less comprehensive organ-level analysis. It's like having a detailed map with inaccurate landmarks.

#1. Generation Lab SystemAge: The Gold Standard for At-Home Testing

After rigorous evaluation, Generation Lab's SystemAge emerges as the clear winner and the most accurate biological age test available. It's the only test that brings research laboratory precision into your home, backed by science from UC Berkeley and Harvard. Here's why it's our number one pick.

19 Individual Organ Ages

SystemAge moves beyond a single biological age number. It acts as a "DNA methylation noise detector," analyzing 460+ biomarkers to calculate biological ages for 19 organ systems. This organ-specific aging approach is revolutionary because it recognizes that your body doesn't age uniformly. Your heart might age faster than your brain, or your immune system might be in better shape than your metabolism.

The 19 analyzed organ systems include:

  • Cardiac (heart health and cardiovascular function)
  • Neurodegeneration (brain aging and cognitive decline risk)
  • Immune System (infection resistance and autoimmune function)
  • Metabolic (diabetes risk and metabolic syndrome)
  • Liver (detoxification and metabolic processing)
  • Kidney (filtration and waste removal)
  • Lung (respiratory function and capacity)
  • Musculoskeletal (bone density and muscle health)
  • Skin (aging and barrier function)
  • Reproductive (hormonal health and fertility)
  • Gastrointestinal (digestive health and gut function)
  • Thyroid (hormonal regulation and metabolism)
  • Pancreatic (insulin production and blood sugar regulation)
  • Adrenal (stress response and cortisol regulation)
  • Vascular (blood vessel health and circulation)
  • Inflammatory (chronic inflammation levels)
  • Oxidative Stress (cellular damage and antioxidant capacity)
  • DNA Repair (cellular maintenance and cancer risk)
  • Cellular Senescence (accumulation of aged, dysfunctional cells)

99% Validated Precision

SystemAge delivers 99% accuracy in detecting biological age changes, validated across 1,600 test cases. This is peer-reviewed science published in Nature, Aging, and GeroScience. The test is built on 20 years of research and backed by co-founder Dr. Irina Conboy, known as the "mother of longevity" for her work in aging research at UC Berkeley.

This accuracy level matters because small changes in biological age can indicate significant health improvements or concerns. A test that's only 60% accurate may miss crucial changes or provide false signals, leading to inappropriate interventions or missed improvement opportunities.

Your Personalized Health GPS

SystemAge delivers more than data. It provides personalized, actionable intervention plans for the 19 organ systems. Instead of generic advice like "eat better and exercise more," you receive specific recommendations based on the fastest aging systems and effective interventions.

The system shows your health journey location and gives directions to your destination. If your cardiovascular system shows accelerated aging, you'll receive heart-healthy recommendations. If your neurodegeneration score is concerning, you'll get brain-specific protocols for cognitive protection.

Track Your Age Reversal

SystemAge shines for biohackers and results-oriented individuals. The test measures aging and tracks age reversal interventions precisely. Documented cases show 5.5-13.6 year reductions in biological age through targeted interventions guided by SystemAge results.

Examples include a 13.6-year reduction in brain aging through targeted cognitive interventions and a 10.4-year improvement in immune system age through personalized supplementation and lifestyle changes. These are measurable, documented outcomes demonstrating the power of precision longevity medicine.

Superior User Experience: Simple, Needle-Free Collection

Despite its sophisticated analysis, SystemAge maintains an exceptional user experience. The at-home collection uses a revolutionary needle-free blood collection device that is virtually painless and takes minutes. Pre-paid return shipping ensures hassle-free sample submission, and your digital report arrives in three to four weeks.

The report is a masterpiece of data visualization, presenting complex epigenetic information in an accessible, actionable format. You don't need a PhD in molecular biology to understand and act on your results.

SystemAge is trusted by 150+ longevity clinics worldwide and endorsed by leading physicians like Dr. Adeel Khan and George Church. When the world's leading longevity experts choose SystemAge for their patients, it speaks volumes about the test's scientific credibility and clinical utility.

Conclusion

After months of research and testing, the verdict is clear. While several tests indicate your biological age, only SystemAge provides a high-definition, 19-system blueprint for optimal health. It excels in clinical-grade accuracy, comprehensive organ-level analysis, scientific validation, and actionable recommendations. SystemAge is the best biological age test of 2025 and it is in a category of its own.

Aging is no longer passive. With the right data, it becomes a game you can win. SystemAge gives you the rulebook, scorecard, and strategy to play that game confidently.