At some point, many of us ask: How old am I really—not by birthdays, but by biology? That’s the promise behind biological age tests—kits that estimate your body’s internal age using DNA, protein levels, and other biomarkers. They’re intriguing and sometimes motivating. But are they truly useful for anyone committed to living a fulfilling 100-year life?

These tests often rely on epigenetic clocks and inflammation or glycan biomarkers to gauge whether you’re aging faster or slower than expected. According toRethinking65, while some findings can be informative, others can vary wildly—by five to nine years depending on the provider.

5 Biological Age Tests You Can Try

If you’re curious and want to explore the space wisely, here are five of the most well-known tests:

• TruAge™ by TruDiagnostic – One of the most science-backed tests available, it evaluates DNA methylation at over 900,000 sites to calculate biological age, pace of aging, and system-specific health insights. It’s used in multiple longevity clinical studies.
• InsideTracker InnerAge 2.0 – A blood-based test that measures key biomarkers like glucose, lipids, and inflammation markers. It also delivers personalized action plans based on your results.
• Elysium Index – Uses a saliva test to assess over 100,000 DNA methylation sites and returns a biological age report, including organ system-specific scores.
• GlycanAge – A unique test that looks at the state of your immune system by analyzing glycan patterns on antibodies. It’s particularly responsive to lifestyle changes like stress and diet.
• NOVOS Age Test – This test analyzes methylation data and provides longevity-related feedback. It also integrates with NOVOS’s supplement and tracking ecosystem.

Should You Take One?

These tests are not miracle tools. But they can serve as a powerful prompt. If your biological age is higher than your real age, it may push you to eat better, sleep more, or move daily. If it’s lower, it can reinforce what you’re already doing well.

The key is this: they’re not crystal balls. They’re snapshots—and only as useful as the actions they inspire.

Use It, Don’t Obsess Over It

Experts agree that lifestyle habits—exercise, stress management, social connection, sleep, and diet—are more impactful than the test itself. While the science behind these tests is promising, they’re best seen as part of a broader commitment to health, not a single solution. As the InsideTracker team notes, about 60% of people who test as “older” than their chronological age show improvements after implementing consistent lifestyle changes.

An Age Brilliantly Perspective

At Age Brilliantly, we advocate for proactive, lifelong decision-making. If a test motivates you to recommit to intentional choices—excellent. But don’t get caught up chasing one number. Ask instead: Am I living in alignment with who I want to become over the next decade?

Biological age testing, when used wisely, supports that journey. The result might be interesting—but the shift in mindset is where the transformation really happens.

Have you taken one of these tests? Did it help you take action, or raise new questions? Join the conversation in theAge Brilliantly Forum to share what you learned—or to find accountability in others walking the same 100-year path.