Best Longevity Blood Test Services, Compared (2026)

The one-sentence version

The "best" longevity blood test isn't the one with the most markers — it's the one that reliably surfaces the four or five cheap, outcome-validated numbers your regular checkup skips (ApoB, Lp(a) once, hs-CRP, HbA1c) and gets them in front of a clinician who will act on them. By that bar, the big DTC lab memberships — Function Health, InsideTracker, Lifeforce, Superpower — are far more alike than their marketing suggests. They differ mainly on price, panel padding, and whether they bolt on a physician or a supplement upsell. None of them clears the bar that actually matters in longevity medicine: testing is not treating. This page grades them on that honest axis. For where lab-membership testing sits in the wider field, see our pillar on longevity medicine: what's proven vs hyped, and for the marker-by-marker breakdown, what longevity biomarker panels actually test.

The category, honestly: more markers ≠ better care

Every service in this roundup sells a version of the same promise: pay an annual fee, get a big blood panel, see your numbers on a clean dashboard with "optimal" ranges, retest later in the year. The headline is always a biomarker count — 50, 100, 100-plus. That number is the least useful thing about the product.

Here's why. A standard annual physical typically orders a basic lipid panel, a metabolic panel, and a CBC, then stops. A longevity panel's genuine value is adding a handful of markers with hard-outcome evidence that the basic checkup leaves out:

• •ApoB counts every atherogenic particle — one ApoB per LDL, VLDL, Lp(a), or remnant — so it measures the number of particles that can lodge in an artery wall, not just their cholesterol cargo. When ApoB and LDL-C disagree (common in metabolic syndrome and diabetes), the particle count is the better predictor of cardiovascular events¹.
• •Lp(a) is a genetically fixed, mostly lifelong-stable particle that independently and causally raises heart-attack and stroke risk — Mendelian-randomization data make the causal case cleanly². You measure it once. A service that re-bills you for it every cycle is padding, not medicine.
• •hs-CRP flags low-grade systemic inflammation and predicted first cardiovascular events at least as well as LDL cholesterol in a large prospective study³. (It's non-specific — a cold spikes it — so a high reading means "recheck when well.")
• •HbA1c is average blood sugar over ~3 months and predicted all-cause and cardiovascular mortality continuously in a population study, with risk rising across the range, even below the diabetes threshold⁴.

Get those four, plus a catch of a treatable thyroid, ferritin, or vitamin-D problem, and a panel has earned its keep. Everything beyond that — the long tail of correlated markers, the "youth hormone" extras — adds line items and a feeling of completeness without adding much independent, actionable signal. Two markers worth naming as traps because nearly every padded panel features them: IGF-1, marketed as a youth hormone but with a U-shaped mortality curve (both low and high associate with higher death rates), and homocysteine, which looks treatable but whose lowering with B-vitamins failed to cut cardiovascular events in large trials. More tubes of blood is not more health.

The services, graded

We'll keep this to the four most prominent DTC blood-test memberships and grade each on the only two axes that matter: does it surface the outcome-validated core, and does it do anything to treat what it finds?

Function Health — the broad panel, test-but-don't-treat

Function is the category's headline act: a ~$499/year membership built around a "100+ biomarker" baseline panel plus a mid-year retest, with physician-ordered and -reviewed labs and a dashboard that flags results against "optimal" ranges. Its real strength is that the long list does include the cheap, outcome-validated core — ApoB, Lp(a), hs-CRP, HbA1c — that most checkups skip, and surfacing them to a motivated person is genuine value. Its honest limit is that roughly half the panel is ordinary bloodwork, much of the tail is correlated padding, and — decisively — it tests without treating. It flags a high ApoB; it doesn't titrate your statin. For a motivated, health-literate buyer with a clinician who'll act, that's fine; for anyone hoping the subscription itself improves their health, it's a category error. We grade it in full in our Function Health review.

InsideTracker — DNA + blood integration, priced per-marker high

InsideTracker layers a one-time DNA component onto recurring blood panels and an algorithmic "InnerAge" plus personalized food/supplement recommendations. The blood science underneath is legitimate where it overlaps the outcome-validated core, but two honest catches define it: it is pricier per marker than Function for a comparably sized panel, and its recommendation engine skews toward supplements and add-ons — a structural conflict when the company also benefits from your acting on its nudges. It's a polished product whose "personalization" is the selling point and the caution at once. We weigh whether its DNA-plus-blood model justifies the premium in longevity clinics vs lab memberships.

Lifeforce — fewer markers, but a clinician and Rx attached

Lifeforce is the one that partly answers the test-but-don't-treat critique. For roughly $129/month plus a kit fee it runs a narrower panel (~50 markers) quarterly, but bundles a physician consult and the ability to prescribe — hormones, metabolic agents — off the results. That's a meaningfully different model: it crosses from measurement toward management. The trade-offs are a narrower panel for the price, a recurring cost that's high for the marker count, and supplement-upsell pressure baked into the membership. Whether the clinician access justifies the premium depends entirely on whether you'd actually use the prescribing. We map that membership-vs-clinic trade-off in longevity clinics vs lab memberships.

Superpower — cheap, big panel, newest and least proven

Superpower is the aggressive price disruptor: a very large baseline panel for a low annual fee (often cited around $199), positioned as "100+ labs for less." On the surface that looks like the best deal in the roundup, and for the cheap outcome-validated core it can be. The honest caveats: it is the newest and least track-recorded of the four, a low price often means more of the panel is the ordinary-bloodwork filler that inflates the count, and like Function it is structurally a test-but-don't-treat dashboard. Cheaper padding is still padding — judge it on whether the actionable core is in there and reliably run, not on the headline number.

How to actually choose

Strip away the marketing and the decision is small:

• •You're health-literate and have a clinician who'll act on results. Pick on price for the outcome-validated core. Function or Superpower get you ApoB/Lp(a)/hs-CRP/HbA1c without a fight; pay the least for a panel that reliably includes them.
• •You want testing and prescribing in one place. Lifeforce is the only one here that crosses into treatment — but you're paying a clinic-adjacent premium, so only worth it if you'll use the physician access.
• •You want "personalized" guidance and don't mind upsell pressure. InsideTracker — eyes open that the recommendations lean toward products it benefits from.
• •You want a biological-age number too. That's a different product with its own limits — a comprehensive blood panel is not an epigenetic-age test. See our honest take on whether biological age tests work at all and the head-to-head epigenetic clock comparison.

And before paying anyone: the open, outcome-validated PhenoAge formula derives a biological-age estimate from a basic blood draw for free, which we cover in free biological-age tests. The two single biggest longevity levers in all of epidemiology aren't even on any of these panels — cardiorespiratory fitness, among the most powerful survival predictors ever measured⁵, and grip strength, which outpredicted blood pressure across 17 countries in the PURE study⁶. No dashboard substitutes for moving them.

Bottom line

The best longevity blood test is the cheapest one that reliably surfaces ApoB, Lp(a) (once), hs-CRP, and HbA1c and gets them to a clinician who'll treat what's abnormal. By that bar Function, InsideTracker, Lifeforce, and Superpower are close cousins separated mostly by price, panel padding, and whether a physician or a supplement store is attached. Function and Superpower compete on the broad-panel-test-but-don't-treat model; Lifeforce alone bundles prescribing at a premium; InsideTracker charges more per marker and leans on supplement recommendations. None of them is itself a health intervention — surfacing a flagged number is not the same as moving an outcome. For an independently graded look at the labs and clinics selling these memberships, see our longevity clinic rankings.