Evidence summary: InnerAge 2.0 (InsideTracker)

InnerAge 2.0 is InsideTracker's biological-age calculation from a standard blood test [3]. There are two ways to get it. You can buy InnerAge 2.0 with a blood test included, drawn in a lab or at home by a mobile phlebotomist [1][3]. Or, with an InsideTracker membership, you can upload blood results from your doctor or other providers and add the InnerAge analysis [1][4]. For lab draws, InsideTracker names Quest Diagnostics [4]; some US states and Canada require the mobile option [3].

InsideTracker says InnerAge uses 17 blood markers for men and 13 for women [3][7]. Its developer documentation also lists body mass index (BMI) as an input for both [6]. The result appears in your InsideTracker account. According to InsideTracker's developer documentation, it gives an age estimate next to your calendar age, the date of the blood test, a "strength" value, and how much each marker adds to or takes off the estimate [5]. InsideTracker suggests updating the analysis every 3 to 6 months, and each update is a new paid analysis [3][4].

The laboratory measures routine blood markers, such as glucose, HbA1c (a longer-term blood sugar measure), cholesterol, albumin, a liver enzyme, hormones and blood-cell counts [6]. BMI comes from body data in your profile [5]. Those are the only measurements.

The age itself is calculated by InsideTracker's own model. InsideTracker calls it "a proprietary summary measure based on blood biomarkers and body mass index (BMI)" [5]. According to InsideTracker:

• The model is based on "a method described in a peer-reviewed paper by Klemera & Doubal", a statistical method for estimating biological age published in 2006, combined with InsideTracker's own customer data [7][12].
• A marker was included if it showed a statistically significant link with calendar age in InsideTracker's data, separately for men and women [6][7].
• Markers more strongly linked with age carry more weight, and your values are compared with InsideTracker customers of the same age and sex [3][8].
• Those customers are "an active, health-conscious population", studied through "tens of thousands of data samples" [8].
• The model "uses machine learning to consistently update reference data" [8].

The developer documentation also says the model "uses age-related health outcomes" [5]. We found no description of which outcomes, or how they are used. In the sources we reviewed, the model's weights, its reference data, its version history and its accuracy are not published.

InnerAge can be calculated without every marker, as long as a minimum set is present [5][6]. The minimum differs between InsideTracker's pages: four named markers for the membership add-on [4], five in the 2021 launch post [9], and several alternative sets in the developer documentation, some of only two markers [6]. InsideTracker says fewer markers can reduce confidence in the estimate, and the result carries a "strength" value for this [4][5]. The strength scale is not explained in the sources we reviewed.

InnerAge is not Phenotypic Age, a published blood-test age built to predict the risk of death [15]. The InsideTracker pages we reviewed do not mention Phenotypic Age, and the two use different marker sets [6][15].

InnerAge 2.0 is currently rated Insufficient on Compare [1]. The rating concerns the age estimate, read against your calendar age, as an indicator of aging-related health. That is the meaning InsideTracker gives it: "a lower biological age generally indicating a more favorable health profile relative to chronological age" [5]. The rating would be the same for narrower uses, such as estimating calendar age or tracking change between tests. It does not cover the individual blood-test results, which are standard laboratory measurements, or InsideTracker's recommendations. This page explains that rating. It does not change it.

We rate InnerAge 2.0 Insufficient for its own biological-age result. In the sources we reviewed, no published study, by InsideTracker or anyone else, has examined InnerAge's own number: not its accuracy, its link to health or survival, or how much it varies between tests.

• The method is published; the model is not. The Klemera–Doubal method is public [12]. Versions of it, built by other researchers from their own marker sets, have been linked to the risk of death in large US national surveys [13][14]. But the method is a recipe, not a single model: researchers can build new versions "using biomarker sets of their own choosing" [14]. InnerAge is InsideTracker's own version, with its own markers, weights and reference group. Our methodology rates a commercial test "on the evidence for that product’s own output, not for the scientific method behind it" [2].
• No study of InnerAge's results. InsideTracker lists three peer-reviewed papers as "peer-reviewed proof" [10]. Those papers, and the most recent InsideTracker study of over 20,000 users, are about blood markers, fitness-tracker data or the gut microbiome; none reports InnerAge [10][17][18].
• No independent check. In the sources we reviewed, no researchers without InsideTracker ties have studied InnerAge.

The next tier up, Emerging, starts with "Animal studies, pilot human studies, or early-phase trials" [2]. We considered it, because InsideTracker discloses more than many vendors: the method family, the rule for choosing markers, the marker lists and the minimum sets [5][6][7]. We rejected it because Emerging still needs some published human study of the product's own result, and we found none. In the sources we reviewed, four of the criteria in our Insufficient tier fit: "Vendor-only claims without published validation", "No peer-reviewed studies or only vendor-funded studies without independent oversight", "Marketing language exceeds published evidence" and "No independent replication or external validation" [2]. A fifth, "Proprietary models without methodological transparency", fits only partly, because of what InsideTracker does disclose. One of the tier's examples, "Products claiming age reversal without test-retest reliability data" [2], also fits (see the next section). Our confidence in Insufficient is moderate to high.

One published, peer-reviewed study of InnerAge's own results, even a small one run by InsideTracker, could change this rating. It would need to compare InnerAge with outcomes beyond calendar age, such as later disease, physical function or survival, or with a published measure such as Phenotypic Age in the same people.

• "Accurately represents your biological age". An InsideTracker article says the model's machine-learning updates ensure "that your InnerAge accurately represents your biological age" [8]. In the sources we reviewed, no accuracy figures are published. Biological age also has no direct measurement to check an estimate against. Updating the reference data means the model itself changes over time.
• "Roll back the clock". The product page says InnerAge 2.0 is for people looking to "roll back the clock" and is headed "Get younger from the inside out" [3]. We found no published data on how much InnerAge varies between repeat tests, so it is not possible to tell real change from test variation.
• "60% of customers … get younger". The product page says "60% of customers with an InnerAge older than their chronological age get younger on their next test" [3]. The membership page words it differently, without that condition: "60% of customers reduce their InnerAge on their follow-up analysis" [4]. We found no published method or comparison group for this figure. When people are chosen because a first result was high, their next result tends to be lower on average even if nothing changed, an effect called regression to the mean. InsideTracker's own researchers make this point about their blood-marker studies: in a group chosen for out-of-range values, later values "would be expected to show improved follow-up test values simply by chance" [18]. Model updates and different marker sets between tests could also move the number.
• "Biological rate of aging". The product page says InnerAge's markers "most closely measure your biological rate of aging" [3]. InnerAge reports an age at one point in time, not a rate [5]. Its markers were chosen for their link with calendar age [6][7].
• "Verified by the latest available science". The product page says the weighting is based on each marker's "known influence on aging—verified by the latest available science" [3]. Other InsideTracker pages say the markers were chosen, and weighted, by how strongly they are linked with age in InsideTracker's own data [6][8]. We found no published verification.
• "More stable". InsideTracker's 2021 launch post says InnerAge 2.0 "is more stable and less sensitive to daily fluctuations of individual biomarkers" [9]. No data are given for this.

InsideTracker says "Changes to your lifestyle can change your blood biomarker levels and your InnerAge, too" [3]. Because InnerAge is calculated from blood markers, a change in a marker will move the estimate. That is arithmetic, not evidence that a lower InnerAge means better health.

In the sources we reviewed, no study has tested whether any lifestyle change, supplement or programme changes InnerAge, or whether a change in InnerAge goes with a change in health. InsideTracker's published studies of its users report changes in individual blood markers, not in InnerAge [17][18]. Both were observational, and their authors note that this limits what they can say about cause and effect [17][18]. InsideTracker's recommendations, including the supplements its InnerAge articles mention [8], are not evaluated here. This page is not a recommendation to take supplements or to change treatment.

InsideTracker advises: "Retest in 3-6 months to track how you’re aging on the inside" [3]. In the sources we reviewed, there are no published data on how much InnerAge varies between repeat tests. We also found no published short-term repeat-test study of a comparable blood-chemistry age.

Three things InsideTracker describes can make two results harder to compare:

• The model can change. The reference data are updated by machine learning [8][9], so two results may come from different versions of the model. We found no published version history.
• The markers can differ. A result can be calculated from a partial set of markers, with a different strength value [5][6]. Two tests with different markers are not like for like.
• The laboratory can differ. Uploaded results can come from your doctor or other providers [4]. Laboratory methods for some markers change over time, and one published toolkit for blood-chemistry ages adjusts its data for such changes [14]. We found no description of how InsideTracker handles results from different laboratories.

Individual blood markers also vary from one test to the next. InsideTracker's own researchers mention "technical variability in test results" as one reason [18].

An InnerAge result is one estimate, made by a proprietary model from a blood test and BMI. It tells you how your markers compare with those of InsideTracker customers of your age and sex, as weighted by that model. A result younger or older than your calendar age is a gap at one point in time, not a speed of aging [5].

The per-marker breakdown shows which markers move the estimate. A marker can add years "even when the biomarker is inside its personalized optimal zone" [5], so a marker that adds years is not necessarily outside a healthy range. In the sources we reviewed, no study shows that a lower InnerAge predicts better health, or that using InnerAge to guide decisions improves health. InsideTracker's terms say its services are "not intended to provide professional medical advice, diagnosis, or treatment" [11].

Everything on this page about how InnerAge works comes from InsideTracker itself [3][4][5][6][7][8][9]. We have not seen a delivered InnerAge report; outputs are described from InsideTracker's developer documentation and product pages.

InsideTracker's published research is written by its own staff. All authors of the 2026 study of over 20,000 users "are full time employees of InsideTracker and hold stock options" [18]. The 2018 study of 1,032 users lists InsideTracker as the affiliation of seven of its ten authors and declares no competing interests [17]. Neither study reports InnerAge [17][18].

The published validation of other blood-test ages comes from researchers outside InsideTracker [13][14][16]. It shows that some blood-chemistry ages carry information about the risk of death across large groups. For example, in a US national sample of 11,432 adults, a higher Phenotypic Age went with a higher risk of death, after allowing for calendar age [16]. It does not show how well InnerAge's own number works.

InsideTracker sells InnerAge alongside personalised recommendations and action plans [3]. This page does not assess them.

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