Biological age—the age your body actually functions at versus your birth certificate— has become one of the most important metrics in the longevity movement. But with dozens of apps and services claiming to measure it, how do you choose? We've compared the leading biological age apps available for iPhone in 2025 to help you find the right fit.

What makes a good biological age app?

Before diving into specific apps, let's establish what matters:

Scientific validity — Is the biological age calculation based on peer-reviewed research?
Actionable insights — Does it tell you how to improve, not just your current score?
Continuous tracking — Can you monitor changes over time, or is it just a one-time test?
Convenience — How easy is it to use regularly?
Privacy — Where does your health data go?
Cost — Is it sustainable long-term?

Top biological age apps for iPhone (2025)

1. My Bio Age — Best for Apple Watch users

Price: Free
Method: 12 health metrics from Apple Watch/iPhone
Best for: Continuous tracking without blood tests

My Bio Age calculates biological age using VO₂max, HRV, sleep, recovery capacity, resting heart rate, and other metrics already collected by your Apple Watch. The MyBioAge Index™ updates continuously as new data arrives, with weekly digests summarizing changes.

Pros: Free, 100% on-device privacy, continuous tracking, AI health coach, Apple Watch companion app, no blood tests required.
Cons: Requires Apple Watch for best results, doesn't include blood biomarkers.

Standout feature: On-device AI Coach that answers questions about your health data without sending anything to the cloud.

2. Inside Tracker — Best for blood biomarker analysis

Price: $249-$589 per test
Method: Blood biomarker analysis
Best for: Detailed bloodwork-based age assessment

Inside Tracker uses blood tests to measure biomarkers like glucose, cholesterol, inflammation markers, and hormone levels. Their InnerAge 2.0 algorithm calculates biological age from these results with specific recommendations for improvement.

Pros: Detailed blood biomarker analysis, specific supplement and nutrition recommendations, scientific backing.
Cons: Expensive per test, requires blood draw, point-in-time snapshot rather than continuous tracking.

3. Elysium Index — Best for epigenetic testing

Price: $499 per test
Method: DNA methylation analysis
Best for: Gold-standard epigenetic age measurement

Elysium's Index test measures biological age through DNA methylation patterns— considered the most scientifically validated method. You receive a saliva collection kit, send it back, and get results in a few weeks.

Pros: Most scientifically rigorous method, measures true epigenetic age.
Cons: Very expensive, weeks to get results, no continuous tracking, limited actionable guidance.

4. TruDiagnostic TruAge — Best for comprehensive epigenetics

Price: $229-$499 per test
Method: DNA methylation analysis
Best for: Multiple epigenetic age algorithms

TruDiagnostic offers epigenetic age testing with multiple clock algorithms (Horvath, Hannum, PhenoAge, GrimAge, DunedinPACE). More affordable than Elysium with similar methodology.

Pros: Multiple age algorithms, more affordable epigenetic testing.
Cons: Still expensive for regular testing, no continuous tracking.

5. Humanity — Best for daily health scoring

Price: Free with premium tier
Method: Wearable data integration
Best for: Daily biological age rate tracking

Humanity integrates with various wearables to track a "Rate of Aging" score, showing whether your habits are accelerating or decelerating biological aging day by day.

Pros: Multiple wearable compatibility, daily tracking, gamified approach.
Cons: Less focus on absolute biological age, premium features require subscription.

Comparison table

App	Price	Method	Tracking
My Bio Age	Free	Apple Watch metrics	Continuous
Inside Tracker	$249-$589/test	Blood biomarkers	Per test
Elysium Index	$499/test	Epigenetic	Per test
TruDiagnostic	$229-$499/test	Epigenetic	Per test
Humanity	Free/Premium	Wearable data	Daily

Which biological age app should you choose?

Choose My Bio Age if: You own an Apple Watch and want free, continuous biological age tracking with AI insights and complete privacy. Best for daily habit optimization and tracking lifestyle interventions.

Choose Inside Tracker if: You want detailed blood biomarker analysis with specific supplement and nutrition recommendations. Best for quarterly check-ins with actionable data.

Choose epigenetic tests if: You want the most scientifically validated biological age measurement and can afford periodic testing. Best for baseline establishment and annual comparison.

The best approach: Combine methods

The most comprehensive approach combines continuous wearable tracking with periodic blood or epigenetic tests. Use My Bio Age daily to optimize habits and track progress, then validate with annual blood panels or epigenetic tests to confirm your biological age is actually moving in the right direction.

Start with My Bio Age—it's free and uses data you're already collecting. Your Apple Watch knows more about your health than you might realize. My Bio Age turns that data into a biological age score you can improve every day.