7 Biological Age Tests Compared: $3,143.99 to Find the Most Accurate (2025 Review)

Are biological age testing kits accurate?

Over 2 days, I gave more than 20 vials of blood and submitted all kinds of other samples to find out.

The results were striking.

A staggering difference of up to 13.1 years on the same date, for the same person, using different tests.

Why the difference? That’s what we’re about to find out.

In this case study, I’ll share the detailed results of each test and my insights into how they compare & contrast. All to help you decide if these tests are worth taking.

Are you a visual learner? Check out this biological age test result comparison dashboard I built.

BioAge Test Results Comparison Key Takeaways

🧬Nick’s Chronological age is 30.4, and the BioAge results revealed a median of age 30.0, an average of age 30.4, and a range of 13.1 years. Demonstrating significant inconsistencies across products.

🧬TruDiagnostic’s reproducibility (precision) of re-analyzing two samples taken at similar times showed remarkable consistency between biomarkers analyzed on the TruHealth and TruAge tests. My sample values mostly differed by <1%.

🧬Tests vary widely in their sensitivity to major lifestyle interventions (a 2-day dry fast in my case).

🧬Some biological age tests use open source algorithms so consumers (and the scientific community) have insight into their scoring. This is akin to supplement companies disclosing the dosages of their ingredients and should become an industry best practice.

🧬Most results reflect that my nutrition, low-toxic burden lifestyle, metabolic health, movement routine, and neurocognition work for my biology. Results disagreed over the state of my cardiovascular system, microbiomes, and inflammation. The obvious factor linking them is my 2-day dry fast.

🧬For the most accurate depiction of your current lifestyle, I recommend waiting 2-4 weeks after any major disturbances before testing. Testing just 5 days after my dry fast clearly impacted my results.

The Biological Age & Cellular Health Experiment: Nick’s 7 Test Results Compared

I’ve taken several biological age tests since 2022. Invariably, my test results would differ from 1 test to the next.

I thought: What if I took several biological age tests on the same day under the same conditions?

Would I get consistent results? Would I have a clearer picture of my biological age?

So, I decided on 7 health testing services.

The following table provides a quick comparison summary of the tests I took.

How I conducted the testing

I put the 7 tests through a controlled, head-to-head experiment.

Accurately comparing biological age tests requires more than just taking them back to back. It means controlling variables so the results reflect the tests, not external factors.

To keep the playing field level, I made sure each test was taken under the same conditions.

Here’s how the experiment was set up.

The timeline

I completed all seven tests within 36 hours to minimize natural fluctuations.

The first day started at 10:00 AM with my Function Health blood draw (completed at a local Quest Diagnostics lab). Then the next morning, I collected my Viome sample before heading into Quest for part 2 of the standard blood labs. I had 2 hours of meetings, then a late lunch. By 4 PM, I had collected all my samples.

The tests

I chose tests to represent some of the major classes of biological aging and cellular health:

• Epigenetic: DNA methylation analysis (TruAge, TruHealth, AgeRate, TruMe)
• Biochemical/Clinical: Comprehensive blood panels, glycan analysis (Function Health, GlycanAge)
• Multiple analyses: RNA sequencing + multi-omics analysis (Viome Full Body Intelligence)

Sample types included blood, saliva, urine, and stool.

Sample collection

Function Health required about 20 vials of blood to process 120 biomarkers.

They split this over 2 days:

• Day 1: 10 vials
• Day 2: 10 more vials plus a urine sample

The other 6 testing kits were done at home and shipped overnight. Most required just a few drops of blood via finger prick. Each took between 5 and 15 minutes to complete. Fairly simple and easy.

The Tasso+ device did make blood collection a tad bit easier.

Controlling the variables

To reduce noise in the results, I kept the following consistent for all tests:

• Fasting for a usual 14 hours before standard blood labs
• Similar time of day for sample collection
• No supplements for 48 hours before testing
• No intense workouts 48 hours before testing
• No alcohol in the weeks prior
• Hydration with plain water only

Note that, due to the sheer number of tests and scheduling constraints, I had to eat before submitting most of the tests (though they claimed it wouldn’t interfere).

Limitations

Even with strict controls, variation is inevitable.

Different labs use different equipment, and biomarkers can shift significantly day to day, and even hour by hour.

Still, this approach gave each test its best shot at providing an accurate snapshot of my biological age.

2 major factors affected my results:

• A 48-hour dry fast that ended 5 days before testing (Read my dry fasting experience)
• Function Health’s 2-day collection schedule split my bloodwork into 2 days

Alright. Like a good movie, let’s skip right to the results before we go over the science.

Final Results: The Surprising Differences in Nick’s Biological Age Tests

After receiving all my test results, I compiled them into this table.

The results didn’t give me 1 “true” number. They gave me a range: From 24.9 years old on the low end (Function Health) to 38 on the high end (GlycanAge).

That’s a 13-year swing for the same body, same day.

Why such a big spread? I accounted for variables by eliminating them as much as I could…

What were the differences?

For one thing, each test measures aging from a different biological angle, showing that different systems in the body can age at different speeds.

So since certain tests excel at measuring organ systems in the body better than others, the most useful ‘biological age’ depends less on finding a single truth and more on choosing the test that aligns with the aspect of health you care about most.

That’s why one test can put me in my mid-20s while another says I’m pushing 40. It also means that no single test tells the full story.

Comparing Biological Age Tests: Insights, Trends, & Takeaways

After controlling every variable I could, it was time to see how the numbers stacked up.

If each of these methods truly measure biological age accurately, the results should be nearly identical.

Instead, what I found was a spread so wide it makes anyone question which “age” to believe.

To make sense of it, I broke the results down in a variety of ways. First, here is a summary of the data provided by the tests.

Here are the insights I gleaned.

Are biological age tests even accurate?

This bar chart makes the 13.1-year spread crystal clear, from Function Health’s -5.5 years to GlycanAge’s +7.6 years. The green bars show younger-than-chronological results, red bars show older results.

From this, we can see that:

• Across the 7 tests with results, the average difference from chronological age is essentially neutral (0.12 years), but the spread is huge
• The youngest result came from Function Health at -5.5 years (biological age 24.9)
• The oldest result came from GlycanAge at +7.6 years (biological age 38)
• Median difference is 0.4 years, suggesting most results hover close to chronological age, but outliers skew perception.

Taken together, the data suggests that while most biological age tests land close to chronological age, the wide swings between providers highlight just how variable these results can be.

Youngest BioAge

It’s interesting that Function Health came in at –5.5 years, matching my TruAge OMICm result. Considering they used different measurement methods.

Biomarker-based scores (as what Function Health uses), however, can swing within hours, making repeatability a real concern.

You should be able to test the same sample twice and get identical, or at least similar, results. If numbers change drastically from minute to minute, the data isn’t reliable.

Another key factor is whether a test uses your chronological age in its algorithm.

TruAge doesn’t, as confirmed by TruDiagnostic founder Ryan Smith.

Many tests require you to enter your chronological age, but they shouldn’t. Using it will naturally make their estimates seem more accurate than they truly are.

Oldest BioAge

Prior to writing, I just finished a consultation with GlycanAge, which is included in their service.

I was curious why the test showed I was 8 years older biologically than my chronological age. And also why the bioage result was at the other extreme compared to my TruAge results.

The first test, they explained, only reflects the impact of my entire life so far.

Old habits, like a decade of yearly antibiotics, most probably skewed my results and made me appear older.

My years of intense sports overtraining likely aged me on paper as well.

Because of that, the baseline alone doesn’t mean much.

Apparently, what matters more is the 2nd test to really understand how you’re aging. You need a 2nd test to compare against the 1st.

While the test is more stable than others, it also means you’ll see less variation between results.

Their recommendations were also unexpected, such as exercise less and take fewer supplements. Since I already don’t train much, that advice didn’t seem to fit.

What impact does the test type have on biological age?

I wanted to see the effect of different testing technology had on my biological age results by plotting the average ages by testing method.

The result is this table that compares the average biological age for each testing method against chronological age (dashed line).

From the youngest bioage to the oldest, here are the average biological ages by method:

• Health biomarkers analysis: 24.9 years (lowest)
• DNA methylation: 28.51 years (slightly younger than actual age)
• RNA sequencing + multi-omics: 35 years (older)
• Glycan analysis: 38 years (oldest)

When comparing methods, the following pattern emerged in how different testing approaches reported biological age:

• Blood-based multi-biomarker and certain DNA methylation tests skew younger
• RNA sequencing + multi-omics and glycan analysis skew older

This may reflect how each technology measures different physiological systems with different aging rates.

Is there a relationship between turnaround time & biological age?

This scatter plot compares turnaround time (in months) and reported biological age (in years) for the 6 different tests.

This scatter plot shows the following:

• Some of the fastest tests (0.5–0.75 months) gave both the lowest (Function Health, 24.9 yrs) & moderate (Viome, 35 yrs) results
• Some of the slowest tests (~2 months) gave results on both extremes (TruAge OMICm: 25.2 yrs vs AgeRate: 32.05 yrs)

It’s apparent that there is no direct correlation between turnaround time and biological age.

Takeaway: Speed of results isn’t an indicator of a younger or older reported biological age.

How fast do each test respond to lifestyle change?

I decided to try my 1st dry fast before the testing to observe how rapidly tests reflect major lifestyle change (stress).

Obviously, biology works differently around major stresses.

You can see these changes reflected in the data. For example, according to dry fasting researcher Dr. August Dunning, the body burns fatty acids (including omega-3) to produce metabolic water. This prevents rapid death from dehydration.

Referring to my TruHealth results, all of my fatty acid biomarker proxies are within normal range.

Another related observation is a hormone that indicates fullness (leptin) post-meal was far below the normal reference range according to Function Health’s standard test. Yet TruHealth shows that the epigenetic biomarker proxy is well within the standard reference range.

Both of these examples highlight that epigenetic methylation testing is more stable to lifestyle change than traditional blood labs.

Similarly, scientists have long known that the gut microbiome (rather, most microbiomes) can change radically within just a few days.

Logically, we’d expect dry fasting to majorly skew the results of Viome or any microbiome testing.

Variability of standard blood labs depends on the biomarker.

From analyzing the data, this appears to be the order of variability between test types (least to most):

• Glycan testing
• Epigenetic methylation
• Standard blood labs
• Microbiome testing

Although certain lifestyle factors (especially extreme fasting) likely impacts variability of certain markers of glycosylation and some standard blood lab biomarkers.

Carnivore, keto, or vegan: is my diet optimal?

The tests seemed to reach consensus that my diet works very well for my unique biology:

• AgeRate Balanced Diet Benefit Score of 99/100 (great)
• AgeRate Metabolic Health Score of 90/100 (great)
• Glycan Shield is in the 78th percentile (my only good GlycanAge score)
• Viome Metabolic Fitness is Improve (56), rather than Attention (as many of my scores are)

I also have low body fat, measuring at about 4.5% via InBody BIA technology. Though I estimate my body fat levels realistically to be closer to 7-8%, not 4.5%.

Although I’ve followed keto and carnivore for periods in previous years, these days I follow a simple diet.

My diet consists of:

• Organic, seasonal, whole foods
• Balanced macronutrients
• High fiber (I aim for 30+ grams daily)
• Dynamic
• Natural prebiotics & fermented foods
• Ample fruits, vegetables, & clean meat

I consume a wide variety of seasonally available foods. I eat a lot, usually over 3,500 calories daily.

The toxic lifestyle: forever chemicals, heavy metals, and microplastics?

I’ve made a concerted effort over the last 7 years to avoid toxicants and endocrine disrupting chemicals.

I switched out all Teflon appliances (major sources of ‘Forever Chemicals’ like PFAS and PFOS), filter my drinking water with reverse osmosis technology, minimize exposure to bisphenols (BPA in bottles, cans, receipts, etc), and mostly wear organic cotton/hemp clothing. I also eat organic to avoid biocides like glyphosate.

It seems to work:

• AgeRate Tobacco Smoke Exposure Score is 83/100 (Great)
• TruHealth’s Relative Smoking Risk is Low (24.0%)
• TruHealth indicates Normal Toxins (77%)
• TruHealth Acrolein levels are low (16%)
• TruHealth PFOS (Forever Chemical) is low (16%)
• TruHealth PFOA (Forever Chemical) is moderate (70%)
• TruHealth Polycyclic aromatic hydrocarbons (PAH) is low (3%)
• TruHealth Glyphosate (Pesticide) is low (24%)
• Function Health lead (Venous) level is low at 1.7 mcg/dL, & TruHealth lead is 8%

I find it interesting that PFOA is moderate while the related PFOA is low. Although I spent 3 months in India last year (breathing in poor air quality), PAH remains low at 3%. Finally, although I work hard to avoid pesticides, my glyphosate load is still moderate at 70%.

None of my toxin markers are out of reference range, nor are any of my detox metabolites. Likely because I do occasional cellular detox protocols.

High chronic inflammation (“inflammaging”)

Having completed dozens of courses of antibiotics combined with a history of airborne toxic mold exposure, I expected some level of inflammaging.

Fasting, especially dry fasting, is a significant physiological stressor. It’s known to induce acute inflammatory responses during refeeding and immune system shifts as the body adapts.

Interestingly, my inflammation and immunity profiles are evenly contradicting between great and terrible:

• High GlycanAge pro-inflammatory glycan indices (Glycan Mature 72nd percentile, Glycan Lifestyle 74th percentile)
• Viome also rates Inflammatory Activity as Improve (53) & Inflammaging as Improve (39), not ‘Attention’
• AgeRate Chronic Inflammation Score is 73/100 (Great)
• TruHealth Inflammation Markers are Normal (67%)
• TruHealth specific inflammatory markers like CRP (28.8% lower than population) & IL-6 (33.9% lower than population)
• Function health inflammation (HS-CRP) & immunity markers mostly look normal, aside from a few immune markers (basophils, eosinophils)

GlycanAge suggests a pro-inflammatory glycan profile with a higher “inflammaging” burden. Viome also shows room for improvement. The rest of the tests, however, reveal a contradiction of healthy inflammaging.

Perhaps, it’s because my profile falls outside the typical distribution of GlycanAge reference populations. The GlycanAge result could highlight a specific susceptibility within my immune glycosylation, even if other overall lifestyle and other biomarkers are protective.

GlycanAge also notes that professional athletes and those that exercise beyond a moderate regimen have older GlycanAges.

Would 2 separate repeated samples get the same results?

Both TruDiagnostic’s TruHealth and TruAge tests require different samples yet report some of the same biomarkers. I figured, this was the perfect time to test the consistency and repeatability of the tests. Scientists call this degree of repeatability, ‘precision’.

I submitted each sample back to back.

As claimed, the biomarkers are nearly identical between tests.

It appears that TruDiagnostic’s marketing claims of precision are indeed accurate.

Biological Age: Your Cellular Longevity Report Card

Biological age measures your body’s functional and cellular health and shows how long you might stay healthy.

It goes beyond calendar/chronological age, which is simply the number of years you’ve been alive.

Biological age matters more than chronological age.

A younger biological age is linked to longer healthspan, or years lived without disease or disability.

On the other hand, a higher biological age is associated with chronic diseases like heart disease, diabetes, and dementia.

Studies show biological age better predicts mortality, chronic disease onset, and long-term functional outcomes [BMC Geriatr, Geroscience, South Med J].

Knowing your biological age motivates you to adopt healthier habits. Re-testing then lets you track their impact and make informed adjustments to improve your well-being and support longevity.

It’s one of the fundamental longevity tips to improve your healthspan.

For this case study, I used these 7 tests to measure my biological age and other health biomarkers:

• TruDiagnostic TruAge + TruHealth
• AgeRate Longevity Panel
• GlycanAge
• TruMe Age
• Viome Fully Body Intelligence
• Function Health

How biological age tests work

There are various types of biological age tests, each using different technologies. Some use an epigenetic approach, others a biochemical and clinical approach.

Then there is also a combination of these 2 approaches.

Here’s a quick breakdown of the major approaches.

DNA methylation analysis (epigenetic approach)

DNA methylation tests measure tiny chemical tags (methyl groups) that attach to your DNA.

These tags control which genes are switched on or off, influencing how your cells function.

As you age, methylation patterns change in predictable ways. Algorithms use those patterns to estimate your biological age.

Sample types: Blood (most accurate), saliva, or cheek swab

Glycan analysis (biochemical approach)

Glycans are sugar molecules attached to proteins that help them work properly, especially immune proteins like IgG.

The pattern of these sugars shifts with age, inflammation, and lifestyle changes.

By mapping those patterns, glycan analysis reveals your biological age and immune health status.

Sample type: Blood

RNA sequencing combined with AI-driven multi-omics analysis (hybrid epigenetic & biochemical approach)

RNA carries genetic instructions and directly controls which proteins your cells make.

RNA sequencing identifies which genes are active at the time of testing. Essentially a live readout of cell activity.

Multi-omics analysis adds layers like protein, metabolite, and microbiome data for a more complete picture of your body’s aging process.

Advanced AI then compares your molecular profile to massive datasets to estimate biological age.

Sample types:

• Blood (gene expression)
• Stool (gut microbiome)
• Saliva (oral microbiome)
• Occasionally skin or tissue biopsies for specific tissue insights

Analysis of multiple health biomarkers (biochemical & clinical approach)

This method measures dozens or even hundreds of lab biomarkers, from cholesterol and inflammation levels to hormone balance and organ function.

Advanced algorithms, like phenotypic age models, combine these markers into a single score that reflects your biological age and predicts health risks.

It’s less about cellular changes and more about your body’s overall functional status.

Sample type:

• Blood (most comprehensive & reliable)
• Urine (for kidney function, metabolic waste)

Nick’s Experience with Each Test

Below are my first-hand experiences with each biological age test. I’ve kept the descriptions neutral so you can see how each test works, what’s included in the report, and how easy (or challenging) it is to understand the results.

TruDiagnostic TruAge

TruAge focuses on DNA methylation, using epigenetic clocks (OMICm, SYMPHONY Age, DunedinPACE) from a single finger-prick blood sample.

Together, they cover biological age, pace of aging, and even organ-specific ages.

Learn more about my experience and detailed results for this test in my full TruAge Review.

TruDiagnostic TruHealth

Paired with TruAge for a full-spectrum view, TruHealth measures nutrition status and system-level health.

It uses DNA methylation analysis and epigenetic biomarker proxies (EBPs) to analyze over 110 biomarkers.

Read my TruHealth review to learn more.

AgeRate Epigenetic Longevity Panel

AgeRate determines biological age by analyzing epigenetic markers in your blood using DNA methylation technology. It examines over 50,000 epigenetic markers related to cellular aging.

AgeRate has a whole ecosystem built around the test through the app, actively encouraging the habits that improve your EpiAge.

TruMe Labs Age

TruMe is budget-friendly and saliva-based, making it one of the least invasive options.

TruMe makes at-home epigenetic testing a lot simpler using saliva testing (although, unfortunately less validated).

ProHealth, a great source for longevity supplements, features TruMe’s TruAge Explorer on their site.

GlycanAge

GlycanAge measures inflammation-related aging by analyzing sugar molecule patterns on immune proteins (IgG).

It analyzes sugar molecules on immune proteins, which likely ties closely to gut and immune health.

GlycanAge features a diverse Scientific Advisory Board of experts from glycobiology, immunology, longevity, and more.

They’ve actively researched aging science for 20+ years and have accumulated numerous studies showing the link between glycans and aging.

Viome Full Body Intelligence Test

Viome uses RNA sequencing plus microbiome data and AI to evaluate gene activity, microbiome health, and biological age.

This is the only test that measures both the health of your gut microbiome and also your human cells.

Read my Viome Test Kit review here.

Function Health

Membership-based testing that covers 100+ lab markers for health and longevity insights, including biological age.

While my score aligned with TruAge (~25 years), this method can vary by the hour.

Function Health gives you over 100 blood tests that would otherwise be nearly impossible for the average person to obtain (with only a few vials).

Are Biological Age Tests Worth It? My Take After Testing

Actionable quantification is the scaffolding allowing biohackers to optimize health, longevity, and performance.

Biological age testing gives us a snapshot into how well our internals function relative to our calendar age.

Though its still in its relative infancy, this technology shows tremendous promise.

Many companies and products have arisen over the last few years. I took 7 tests that would’ve costed me about $3,143.99 to compare results. What did I find?

Tremendous variability in their estimation of my biological age, ranging from 24.9 years old, to a high of 38 years old. The basic stats are ironic:

• Chronological age: 30.4 years old
• Average biological age: 30.4 years old
• Median biological age: 30 years old
• Range of biological age: 13.1 years

Based on that alone, it’d be easy to dismiss these tests as utterly useless.

Yet they also provided nuanced insights. For example, the test results on diet, metabolic health, and toxin exposure largely aligned. I can spot potentially problematic areas where I’m supplementing yet still have imbalanced levels of certain metabolites.

I learned that GlycanAge likely still reflects my 10+ years of annual antibiotics and heavy fitness overtraining. And that, although Function Health reports elevated 3-month blood sugar (HbA1c), my fasting insulin, fasting glucose, homocysteine, and corresponding TruHealth EBPs lessen the concern.

Armed with this information, here’s what I recommend:

• 1-2X annual standard bloods labs
• 1-4X annual TruAge test
• 1X biennial GlycanAge test

I don’t consider standard blood labs to be an accurate measure of biological age since they unstable. They still rely mostly on biomarkers that fluctuate dramatically from hour to hour and day to day.

Biohackers and advanced longevity enthusiasts who want to go one level deeper may consider adding in 1-2X annual TruHealth tests too. This way, you’re getting the maximum insights with a minimalist testing schedule.

You can also wait. The cost of diagnostic testing should only continue decreasing thanks to technological advances and increasing economies of scale.

What about you? Have you tried any of these biological age test kits? How was your experience? Drop a comment below and let me know.

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