Epigenetic Clock Tests Compared: TruAge, GlycanAge, and OMICmAge

At a Glance

The conversation about biological age testing has matured considerably since the early days of single-clock estimates. We now have competing commercial platforms each taking a meaningfully different technical approach — and that diversity matters clinically. Ordering the wrong panel for a patient’s specific question wastes money and, more importantly, leaves the most actionable data on the table.

I have used all three of the major platforms with patients and have developed strong views on when each is appropriate. What follows is a structured comparison to help clinicians and well-informed patients make that call.

Why the Technology Difference Matters

Before comparing platforms, it is worth understanding why the underlying measurement technology produces genuinely different clinical signals — not just different presentations of the same data.

DNA methylation clocks read chemical tags (methyl groups) at specific CpG sites across the genome. These patterns shift predictably with age and are strongly correlated with disease risk. Different clock algorithms weight different CpG sites and therefore emphasize different biological processes — some track immune aging, others mitochondrial function, others pace of aging in real time.

Glycan profiling (GlycanAge’s approach) measures how sugar chains attached to IgG antibodies change with age and inflammation. Glycan patterns integrate decades of cumulative immune and inflammatory signalling in a way that methylation clocks do not capture directly. This makes glycan age surprisingly responsive to lifestyle and dietary changes — sometimes changing detectably within weeks of an intervention.

Multi-omic integration (OMICmAge’s approach) combines methylation with circulating protein levels (proteomics) and small-molecule metabolites (metabolomics). The result is a biological age estimate trained on more biological dimensions simultaneously. The trade-off is complexity: more data requires more sophisticated interpretation and the reference populations for multi-omic clocks are currently smaller than for methylation-only clocks.

TruAge Complete (TruDiagnostic)

TruDiagnostic has established the strongest track record in the clinical longevity space and the product shows it. TruAge Complete runs the EPIC array — the same platform used in most academic methylation studies — giving you access to the full constellation of validated clocks from a single panel.

What you get: DunedinPACE (pace of aging), GrimAge v2, PhenoAge, PCHorvath, PCGrimAge, telomere length estimate, immune cell composition, and a proprietary “TruAge Intrinsic” score. The breadth is unmatched.

Clinically, DunedinPACE is the most actionable clock for intervention monitoring. It measures the pace at which a person is currently aging rather than an accumulated age estimate — so it responds to interventions over a 3–6 month window. A patient starting a rapamycin protocol, changing diet, or beginning a CR mimetic can plausibly see their DunedinPACE shift in a single testing cycle. GrimAge, by contrast, integrates decades of exposure and is more stable — useful for risk stratification but slower to show change.

Strengths: Largest reference database for methylation, reproducible lab conditions, detailed algorithmic explanations, quarterly retesting price structure.

Limitations: Blood spot collection requires careful technique; a small percentage of samples need to be re-run. Customer portal, while comprehensive, can overwhelm non-clinician patients with the volume of clocks reported.

My recommendation: TruAge Complete is the default first test for longevity patients. If a patient can only afford one panel, this is it.

GlycanAge

GlycanAge measures biological age through IgG glycosylation patterns — a completely different biological layer from methylation. This is both its limitation and its unique strength.

The glycan-inflammation link is real and clinically underused. IgG glycans shift toward pro-inflammatory profiles with age, metabolic syndrome, sedentary behaviour, and ultra-processed food consumption. They shift toward anti-inflammatory profiles with aerobic exercise, Mediterranean-pattern diets, reduced alcohol, and certain supplements including fish oil and vitamin D. No methylation clock captures this in real time.

Responsiveness is the killer feature. In the published GlycanAge validation studies and in my own patient cohort, glycan-based biological age can move meaningfully in 8–12 weeks with targeted lifestyle change. This gives patients an unusually fast feedback loop. For a patient who is motivated but skeptical that dietary changes matter, a 3-month repeat GlycanAge after an elimination protocol is one of the most compelling re-engagement tools I have.

Strengths: Unique glycan readout, fast response to lifestyle, clear single-number output, good patient comprehension.

Limitations: Single-axis readout — you learn one dimension of aging, not a panel. Does not report methylation clocks, so you cannot track the interventions (rapamycin, metformin, senolytics) that operate primarily on epigenetic pathways. Smaller longitudinal dataset than TruDiagnostic.

My recommendation: GlycanAge is the right add-on when inflammaging, metabolic health, or dietary responsiveness is the primary question. It pairs well with TruAge rather than replacing it. For a patient focused purely on diet and exercise optimization, GlycanAge as the sole panel is defensible.

OMICmAge

OMICmAge represents the frontier of multi-omic biological age estimation. By combining methylation data with plasma proteomics (hundreds of circulating proteins) and metabolomics, it trains a composite biological age on more dimensions than any single-omic platform.

The proteomics layer adds what methylation alone misses. Circulating proteins reflect real-time organ-specific function — liver, kidney, heart, brain, immune — in a way that methylation in blood cells does not. Proteins like GDF-15, Cystatin C, NT-proBNP, and ANGPT2 have well-established disease-risk associations, and incorporating them into a biological age composite increases predictive validity for mortality and disease onset.

The metabolomics layer captures nutritional status, mitochondrial efficiency, and gut microbiome outputs. Branched-chain amino acid ratios, short-chain fatty acid proxies, and kynurenine pathway metabolites all influence aging trajectories and respond to interventions.

Strengths: Most biologically comprehensive estimate available commercially, rich sub-score reporting by organ system, good for identifying the primary driver of elevated biological age.

Limitations: Higher cost, requires venipuncture (not dried blood spot), reference databases for multi-omic clocks are smaller and less globally validated than methylation-only clocks, longer turnaround. The composite integrates so many signals that isolating which intervention moved the score is harder — a feature that makes individual intervention monitoring less clean.

My recommendation: OMICmAge is appropriate for patients who want a comprehensive initial characterization, who have complex multi-system concerns, or who are participating in longevity research. For monitoring a specific intervention (e.g., rapamycin titration), TruAge’s DunedinPACE gives cleaner signal.

How to Choose: A Clinical Decision Framework

Start with TruAge if: you are establishing a longevity baseline, monitoring pharmacological interventions (rapamycin, metformin, senolytic cycling), or need the most validated methylation clock panel.

Add GlycanAge if: inflammaging, metabolic syndrome, dietary compliance, or lifestyle coaching is central to the patient’s program. Also consider it as the sole panel for cost-constrained patients whose primary intervention is diet and exercise.

Use OMICmAge if: you want the richest omic fingerprint at baseline, the patient has multi-system concerns that a single-omic readout won’t characterize, or you are tracking a complex multi-modal protocol and want organ-level sub-scores.

For serial monitoring, TruAge Complete quarterly is the workhorse. The combination of DunedinPACE (short-interval sensitivity) and GrimAge/PhenoAge (longer-term risk anchoring) in a single panel gives the best intervention-tracking ROI.

Interpreting Results: What I Tell Patients

A biological age younger than chronological age is reassuring but not a destination. A biological age older than chronological age is a prompt to identify modifiable drivers, not a sentence. The most actionable number is usually DunedinPACE — a pace above 1.0 means aging faster than average; below 1.0 means slower.

When I review results with patients I always anchor them to the interventions we are running, not to their birth year. The question is not “how old does your biology look today?” but “is the biology moving in the right direction under the protocol we are running?”

A result that shocks a patient into action and then confirms that their changes are working is worth more clinically than a comprehensive panel that overwhelms them into paralysis.

The Limitation Neither Vendor Will Lead With

All three platforms share a common limitation: they were trained primarily on European and North American cohorts. Reference ranges and clock calibrations may not translate with equal accuracy across ancestries. For patients from underrepresented genetic backgrounds, interpret absolute scores with appropriate humility and prioritize directionality (is the score improving?) over absolute comparison to population norms.

Additionally, all epigenetic clocks measure methylation in circulating blood cells, which reflects immune aging specifically — not brain, liver, or cardiac aging directly. A blood-based clock in a 60-year-old with excellent immune aging but subclinical cardiac disease will underestimate the true risk. Paired cardiovascular biomarkers (Lp(a), hsCRP, NT-proBNP, coronary calcium score) remain essential components of a longevity assessment that no epigenetic clock replaces.

Related Articles

• Biological Age Testing — What Epigenetic Clocks Actually Measure
• Rapamycin for Longevity — Evidence, Dosing, and Patient Selection
• Functional Medicine Diagnostics — The Lab Panel I Run First
• NAD+ Supplementation Guide — Mechanisms, Dosing, and Monitoring
• Longevity Protocol Overview — How We Structure a Longevity Programme

References

1. Trapp A, Kerepesi C, Gladyshev VN. “Profiling epigenetic age in single cells.” Nat Aging. 2021;1:1189–1201. PMID: 35603253
2. Lu AT, Seeboth A, Tsai P-C, et al. “DNA methylation-based estimator of telomere length.” Aging (Albany NY). 2019;11(16):5895–5923. PMID: 31422385
3. Belsky DW, Caspi A, Corcoran DL, et al. “DunedinPACE, a DNA methylation biomarker of the pace of aging.” eLife. 2022;11:e73420. PMID: 35029144
4. Lauc G, Vojta A, Zoldoš V. “Epigenetic regulation of the N-glycome: Evidence for a connection between epigenetic regulation and N-glycosylation as a mechanism of cellular and tissue homeostasis.” Biochim Biophys Acta. 2014;1840(1):419–425. PMID: 23523949
5. Ahadi S, Zhou W, Schüssler-Fiorenza Rose SM, et al. “Personal aging markers and ageotypes revealed by deep longitudinal profiling.” Nat Med. 2020;26(1):83–90. PMID: 31907459
6. Levine ME, Lu AT, Quach A, et al. “An epigenetic biomarker of aging for lifespan and healthspan.” Aging (Albany NY). 2018;10(4):573–591. PMID: 29676998
7. McCartney DL, Hillary RF, Stevenson AJ, et al. “Epigenetic prediction of complex traits and death.” Genome Biol. 2018;19(1):136. PMID: 30223874