Biological Age Tests Compared: GlycanAge vs DNA, Epigenetics & Others

Comparison of the different biological pathways measured by leading aging clocks to help you choose the right tool for tracking longevity.

How do biological age tests compare?

Biological age tests are not interchangeable. GlycanAge reflects immune and inflammation biology through IgG glycosylation, epigenetic clocks estimate age or “pace” from DNA methylation, telomere tests estimate telomere length, and clinical clocks combine routine labs. Each captures different pathways and has different strengths for tracking change.

A good comparison starts with what the test is *built* to represent: (1) the biology measured (immune/inflammation, methylation, telomeres, or clinical physiology), (2) the endpoint it was trained or validated against (chronological age, morbidity/mortality, or pace-of-aging), and (3) analytic repeatability (how stable results are when nothing meaningful changes). Large comparisons of epigenetic clocks show that different clocks relate differently to different diseases and outcomes, so “best” depends on the goal. Glycan-based measures are rooted in IgG glycome biology, which is strongly linked to immune aging and inflammatory regulation and can respond to sustained interventions. Telomere length is a biologically important marker, but measurement approach and use case matter; it can be clinically impactful in specific contexts (for example, suspected telomere biology disorders) yet less informative as a general lifestyle-tracking score.

GlycanAge vs epigenetic clocks

GlycanAge and epigenetic clocks measure different aging biology. GlycanAge estimates biological age from IgG glycosylation patterns tied to immune regulation and chronic inflammation. Epigenetic clocks use DNA methylation patterns and may be optimized for chronological age, mortality risk, or pace of aging. Agreement is partial, not guaranteed.

If you want an immune/inflammation–anchored signal that is meaningfully connected to IgG function, glycan measures are conceptually well aligned. If you want a methylation-based “pace” metric designed for intervention studies, DunedinPACE is a prominent example with strong test–retest reliability and trial evidence of modifiability. For risk-oriented clocks, second-generation methylation clocks such as DNAm PhenoAge (and others) were built around health outcomes and can relate more strongly to morbidity/mortality than clocks trained only on chronological age. Practically, these tools can complement each other: glycans emphasize immune aging; methylation clocks emphasize genome-regulatory aging patterns.

GlycanAge vs telomere tests

Telomere tests and GlycanAge answer different questions. Telomere length reflects aspects of cellular replication history and telomere biology, while GlycanAge reflects immune/inflammation state via IgG glycans. Telomere length can be clinically useful in specific indications, but as a general “longevity score” it is often noisy and context-dependent.

Telomere length measurement has multiple laboratory methods with different strengths and limitations, and results can vary with assay choice and sample context. In population studies, leukocyte telomere length and epigenetic clocks are related but only modestly, meaning telomeres are not a substitute for other aging clocks. Where telomere testing becomes more clinically actionable is in targeted scenarios (for example, fibrotic interstitial lung disease workups), where very short telomeres can influence management decisions. For lifestyle tracking, telomere length is generally harder to interpret than multi-marker aging readouts, and it should not be treated as a standalone “biological age.”

GlycanAge vs DNA tests

“DNA tests” usually mean genetic variant testing (including polygenic risk scores), which estimates inherited predisposition and does not measure current biological aging. GlycanAge measures a dynamic biomarker pattern (IgG glycans) that can change with long-term health and lifestyle influences. They are complementary: one is predisposition, the other is state.

Genetic testing can provide limited risk information, but it typically cannot tell whether you will develop a condition, how severe it would be, or how it will progress. Polygenic risk scores compare your inherited risk to others, but clinical use is still evolving and must be interpreted carefully. Because genetics are largely stable across life, DNA tests are not designed to track lifestyle-driven improvement. Glycan-based (and many other biological age) measures are better suited to monitoring change over time, as long as the marker is repeatable and interpreted alongside standard clinical risk factors.

GlycanAge vs TruDiagnostics / Function Health / NOVOS

GlycanAge is an IgG glycan test focused on immune/inflammation aging. TruDiagnostic and NOVOS prominently offer epigenetic (DNA methylation) aging outputs, often including pace-of-aging measures like DunedinPACE, sometimes bundled with other biomarkers. Function Health emphasizes broad lab-based health assessment and may present biological-age-style summaries depending on the panel.

A fair comparison requires checking the exact model(s) reported: a methylation clock trained on chronological age is not the same as a mortality-trained clock or a pace-of-aging measure, and large head-to-head research shows clocks can behave differently across outcomes. Also separate “what is measured” from “how it’s packaged.” A bundle may include an aging score plus nutrition markers, lipids, inflammation markers, or organ-function estimates; that can be useful for actionability, but it also makes cross-brand comparisons harder because you’re not comparing like-for-like. When choosing, prioritize transparency about what biomarkers are measured, what the score is validated to predict, and how repeatable the measurement is.

Which longevity tests are worth the money?

A longevity test is most worth the money if it is analytically reliable, validated against meaningful outcomes, and leads to actions you will actually take and track. In many cases, spending on high-quality standard clinical labs and risk-factor control yields clearer benefits than chasing small changes in a single “age” number.

A practical value checklist is: (1) reproducibility (test–retest stability), (2) clinical validity (links to morbidity/mortality or robust health outcomes), (3) interpretability (you can connect results to modifiable targets), and (4) longitudinal design (repeat testing under similar conditions). Outcome-linked composite measures like Phenotypic Age / DNAm PhenoAge illustrate why interpretability matters: when a model maps onto known risk biology, it is easier to anchor to actionable clinical targets. If a test cannot explain what it measures, how precise it is, and what a “meaningful change” looks like, it is easier to over-interpret noise.

What is the best longevity test?

There is no single best longevity test. The best choice depends on your goal: outcome prediction, intervention tracking, or mechanistic insight. Evidence shows different epigenetic clocks perform differently across different diseases and outcomes, and different biological layers (methylation, glycans, telomeres, clinical labs) capture different aspects of aging biology.

If your goal is risk context, outcome-trained clinical or epigenetic models may be more informative than clocks trained only on chronological age. If your goal is tracking intervention response, pace-oriented measures can be preferable because they are designed to quantify change over time, and there is randomized trial evidence of modifiability for DunedinPACE in the CALERIE intervention. If your goal is immune/inflammation aging, IgG glycan measures have strong biological grounding and demonstrated responsiveness to sustained changes. “Best” is therefore best framed as “best fit for purpose.”

What’s the best biological age test for tracking lifestyle change?

For tracking lifestyle change, the best biological age test is one that is repeatable and demonstrably responsive to sustained interventions. Epigenetic pace measures like DunedinPACE have randomized-trial evidence of modifiability, while IgG glycan age has intervention evidence (for example, weight loss and structured exercise) in peer-reviewed studies.

Look for three properties: reliability (low noise), appropriate time horizon (months rather than weeks), and alignment with the intervention. DunedinPACE was designed for intervention studies and showed slowing in a randomized caloric restriction trial, while other epigenetic “age” clocks changed less in that same setting. On the glycan side, substantial weight loss and moderate exercise interventions have been linked to shifts consistent with reduced glycan age, supporting use for lifestyle monitoring—especially when the goal is improving inflammatory and immune regulation. Whichever test you choose, interpretation is strongest when paired with objective clinical markers (waist, BP, lipids, HbA1c) and repeated under similar conditions.

Scope disclaimer: This content is for educational purposes only and does not constitute a medical diagnosis or treatment guide.

Scientific grounding: This information is aligned with findings from peer-reviewed research in the fields of aging biology and molecular biomarkers.

GlycanAge provides biological age testing to help individuals monitor their immune health and chronic inflammation patterns over time.