Your birth certificate tells you one thing. Your cells may tell you something else. That gap between chronological age and biological age has become one of the most talked-about metrics in longevity, and a growing number of companies now sell an at-home test kit that promises to quantify it.
Before comparing them, one thing is worth understanding. Each company builds its own model, trains it on its own reference data, and reports the result in its own format. A biological age from one provider is not interchangeable with a number from another, and none of these results is a medical diagnosis or a verdict on your health. They are estimates produced by a specific methodology, and they are most useful when you test the same way more than once and watch the direction of travel.
Here are six options worth knowing, with what each measures and who it tends to suit.
Index is a saliva-based DNA test that reports an overall biological age, a cumulative rate of aging, and system age scores across nine areas: brain, heart, metabolic, immune, inflammation, kidney, liver, hormone, and blood. Because it is an at-home biological age test, you collect the sample yourself, with no finger-prick or lab visit involved.
The analysis runs on what Elysium calls APEX, its Algorithmic Platform for Epigenetic Examination, using a custom methylation chip the company developed with Illumina. The underlying approach was created in partnership with Morgan Levine, Ph.D., of Yale University. Alongside the scores, the report includes over 100 lifestyle recommendations, and results arrive by email roughly six weeks after the lab receives your sample.
Who it's for: Anyone who wants organ-system-level detail without a blood draw. Best feature: The nine system ages, which break a single number into something more specific than one figure can convey. Elysium is clear that Index is not a medical device and is not intended to screen, diagnose, treat, cure, or prevent any condition.
TruDiagnostic works from a finger-prick blood sample and analyzes over a million DNA methylation sites. What sets the reporting apart is the set of named algorithms it draws on: OMICmAge for biological age, developed with Harvard; DunedinPACE for aging speed; and SYMPHONYAge, from Yale, for ages across 11 organ systems.
The report layers in additional measures too, including a telomere length estimate, immune cell composition, and inflammation markers. Results land in a secure portal within three to four weeks of the lab receiving your sample, and the company suggests retesting every three to six months. A four-test annual subscription exists for people who want to track that cadence without reordering each time.
Who it's for: Data-oriented readers who want multiple published algorithms in one report. Best feature: The breadth of what one finger-prick returns.
Tally Health keeps collection about as simple as it gets. TallyAge uses a cheek swab, which you return in a prepaid shipper, and the model behind it was trained on a large commercial cheek swab methylation dataset covering more than 8,000 adults between 18 and 100.
Rather than presenting the score in isolation, the platform sets your epigenetic age against lifestyle inputs you provide, including sleep quality, exercise, diet, stress, and alcohol use, then builds recommendations from there. Results take four to six weeks. The membership option sends a new test every six months, which suits the way these numbers actually move: slowly.
Who it's for: People who want the least invasive collection and a structured plan attached to the result. Best feature: The membership retest rhythm, which turns a one-time curiosity into a trend line.
NOVOS Age also uses a finger-prick blood sample, and the company is direct about why it chose blood over saliva: it points to published, patented immune cell deconvolution methods that work on blood. The report covers biological age, pace of aging using DunedinPACE, organ ages across 11 systems based on a Yale-developed algorithm, and telomere length.
The output runs 55 pages and is organized so you are not left interpreting raw numbers alone: an executive summary, an organ age dashboard placing all 11 systems on one scale, prioritized recommendations, and a longitudinal view once you have more than one result. Turnaround is two to four weeks, and the company advises retesting after six to twelve months, noting that shorter intervals tend to surface measurement noise rather than real change. An AI longevity coach is included for working through the results.
Who it's for: Readers who want depth of explanation as much as depth of data. Best feature: The candor about retest timing.
GlycanAge is the methodological outlier here, and that is precisely why it earns a place. Instead of reading DNA methylation, it analyzes the N-glycosylation of immunoglobulin G, the most abundant antibody in your blood. Collection is still a finger-prick, four drops onto a card, posted back in a prepaid envelope.
The report gives you a biological age alongside an inflammatory profile and the lifestyle factors shaping both, which makes it a different lens rather than a competing version of the same one. Results take three to four weeks, and a call with one of the company's longevity specialists is available for 60 days afterward. Subscription and two-test bundle formats are offered for people planning to retest.
Who it's for: Anyone curious about inflammation as an aging signal, or already holding a methylation result and wanting a second angle. Best feature: The specialist results call, which is rarer in this category than you might expect.
InnerAge 2.0 is not an epigenetic test at all. It runs on a blood biomarker algorithm, drawing on 17 biomarkers for men and 13 for women, including glucose, triglycerides, cholesterol, and albumin, each weighted by how much it varies across the population and over time.
Its most practical quality is transparency about arithmetic. The dashboard shows how many years each individual biomarker is adding to or subtracting from your InnerAge, then builds an action plan from those specific levels. Because it uses conventional blood biomarkers rather than DNA methylation, it offers a very different way of approaching biological age.
Who it's for: Readers who want familiar, movable biomarkers rather than epigenetic clock output. Best feature: Seeing exactly which marker is pulling your number in which direction.
The right pick usually comes down to three things: how you feel about the sample, whether you want a single number or system-level detail, and how committed you are to testing again. A one-off result is a snapshot with limited context. Two or three results from the same provider, spaced months apart, start to tell you something.
Whatever you choose, treat the number as information rather than a verdict. These tests are consumer wellness tools, not clinical assessments, and a score in either direction is not evidence that something is wrong or that anything has been fixed. Used as one input among many, though, they fit neatly into a proactive, data-driven approach to healthspan, which is really the point of measuring anything at all.