Function Health Review: Are 100+ Biomarkers Worth $499/yr?

The one-sentence version

Function Health is a genuinely useful product wrapped in a misleading headline. The "100+ biomarkers" framing implies that more numbers means more health — they don't — but buried inside that long list are a handful of cheap, outcome-validated tests (ApoB, Lp(a), hs-CRP, HbA1c) that most standard checkups skip and that genuinely deserve your attention. The catch is that roughly half the panel is ordinary bloodwork you could get cheaper elsewhere, a chunk of the rest is context or vanity, and the model is structurally test-but-don't-treat: it hands you data and flags, not a clinician fixing your problems. Whether ~$499/year is worth it depends entirely on whether the actionable core justifies the price for you. For where lab-membership testing sits in the field, see our pillar on longevity medicine: what's proven vs hyped and our breakdown of what longevity biomarker panels actually test.

What you actually get for ~$499/year

Function Health is a direct-to-consumer (DTC) lab membership. For an annual fee — positioned around $499, though DTC lab pricing shifts, so treat that as current market info — you get a large baseline blood panel (the "100+ biomarkers" headline), a follow-up retest partway through the year, a clean dashboard that flags results outside "optimal" ranges, and physician-ordered/reviewed labs so a clinician signs off on ordering and on results requiring it. What you generally do not get is ongoing treatment: Function surfaces and tracks numbers; it is not a longevity clinic prescribing and managing therapy. That distinction — testing versus treating — is the single most important thing to understand before paying, and it's the structural catch of the entire DTC lab band, which we map in longevity clinics vs lab memberships.

The good: it surfaces the markers a basic checkup skips

Here's the honest case for Function. A standard annual physical often orders a basic lipid panel, a metabolic panel, and a CBC — and stops. Function routinely includes several markers with strong hard-outcome evidence that your regular checkup probably doesn't, and surfacing them is real value:

• •ApoB. The single most useful upgrade over a basic lipid panel. Every atherogenic particle — LDL, VLDL, Lp(a), remnants — carries exactly one ApoB, so it counts the number of particles that can lodge in an artery wall, where standard LDL cholesterol measures only the cargo. When the two disagree (common in metabolic syndrome and diabetes), the particle count is the better predictor of cardiovascular events¹, a conclusion echoed by LDL-particle-number data from the Framingham Offspring cohort², and major lipid guidelines now treat ApoB as a measurement target³.
• •Lp(a). A genetically set, mostly lifelong-stable particle that independently and causally raises heart-attack and stroke risk — Mendelian-randomization data make the causal case cleanly⁴. You measure it once; a high result reshapes how aggressively everything else gets managed. A panel that includes it is doing something genuinely useful (one that re-bills you for it every cycle is padding).
• •hs-CRP. A marker of low-grade systemic inflammation that predicted cardiovascular events at least as well as LDL cholesterol in a large prospective study⁵ and was used to guide statin treatment with a hard-outcome benefit in the randomized JUPITER trial⁶. (Caveat: it's non-specific — a cold or injury spikes it — so a single high reading means "recheck when well.")
• •HbA1c. Average blood sugar over ~3 months, and not just a diabetes test: it predicted all-cause and cardiovascular mortality continuously in a population study, with risk rising across the range including below the diabetes threshold⁷.

If Function's panel gets you these four numbers — plus catches a treatable thyroid, ferritin, or vitamin D problem people often misattribute to "aging" — it has earned a meaningful slice of its fee. That's the legitimate core.

The catch: roughly half is basic labs, and the long tail inflates the number

Now the honest case against the framing. The "100+ biomarkers" headline does a lot of work, and most of it is marketing:

• •A large share is ordinary bloodwork. The CBC, comprehensive metabolic panel, standard lipids, thyroid, electrolytes, kidney and liver markers — these are useful, but they're the same basic labs available through a primary-care order or a cheap DTC requisition. Bundling them into a "100+" count makes the panel look more exotic than it is.
• •Much of the tail is correlated padding. Most of the extra markers track with the cheap Tier-1 core, so they add line items and a sense of completeness without adding much independent, actionable signal. More tubes of blood is not more health.
• •Some featured markers are vanity or actively misleading as targets. Two examples worth naming:
• •IGF-1 is marketed as a youth hormone, but its mortality relationship is U-shaped — both low and high IGF-1 associate with higher mortality in meta-analysis⁸. "Raise your IGF-1 to feel younger" is biologically naïve, and chasing it in either direction is a mistake.
• •Homocysteine associates with cardiovascular risk, so it looks worth treating — but large randomized trials that lowered it with folic acid and B vitamins (HOPE-2) did not reduce cardiovascular events⁹. It's a passenger, not a driver; measuring it rarely changes what you should do.

The structural limit: it tests, it doesn't treat

This is the part that decides the grade. Function is a measurement product. It will flag that your ApoB is high or your HbA1c is creeping up — but it does not then manage you: titrate a statin, build a nutrition plan, recheck and adjust. You're handed data and "optimal range" flags, and the work of acting on them falls to you and whatever clinician you already have. For a motivated, health-literate person who will take an abnormal ApoB to their doctor and push for treatment, that's fine — even empowering. For someone hoping the membership itself improves their health, it's a category error: surfacing a number is not the same as moving an outcome, and a panel full of green-and-red flags can create a false sense that paying for the data is doing something. The two biggest longevity levers in all of epidemiology aren't even on a blood panel — cardiorespiratory fitness, among the most powerful survival predictors ever measured¹⁰, and grip strength, which outpredicted blood pressure across 17 countries in the PURE study¹¹ — and no membership dashboard substitutes for the boring, proven work of moving them.

There's also a soft conflict to watch in the broader DTC-lab ecosystem: when "optimal" ranges are drawn tighter than clinical reference ranges, more of your results land in the amber zone — which can nudge you toward supplements or add-on testing. Function's labs being physician-reviewed mitigates the worst of this, but the incentive to make a panel feel like it found something is baked into the category, and a tighter-than-clinical "optimal" band is the mechanism. Read your flags against standard clinical thresholds, not just the dashboard's color coding.

The grade, and how we got there

Two axes again, because conflating them is the trap:

• •As a way to surface outcome-validated markers your checkup skips: moderate-to-strong. ApoB, Lp(a), hs-CRP, and HbA1c are real, cheap, hard-outcome-linked tests, and getting them in front of a motivated person is genuine value.
• •As a "100+ biomarker" health upgrade that improves your health: weak. Roughly half is basic labs, much of the tail is correlated padding, a few featured markers (IGF-1, homocysteine) are vanity or misleading as targets, and — decisively — it tests without treating.

That split lands the letter grade in the middle: a B for the actionable core, a C for the model most people think they're buying. If you're health-literate, have a clinician who'll act on the results, and value the convenience of getting ApoB and Lp(a) without a fight, it can be worth it. If you're hoping a subscription will make you healthier, the money does more in a standard outcome-validated panel plus actually treating the few markers that matter. We run that whole cost-benefit in are longevity clinics worth it?.

Who should and shouldn't buy it

• •Reasonable buyer: a motivated, health-literate person who wants ApoB, Lp(a), hs-CRP, and HbA1c surfaced conveniently and will take abnormal results to a clinician who treats them.
• •Poor fit: someone expecting the membership itself to improve their health, or who'll re-read a long list of green/amber flags as a scoreboard. For most of that budget, a targeted outcome-validated panel does the job — and if you want a biological-age number too, the open PhenoAge formula derives one from a basic blood draw for free, as we cover in free biological-age tests. (And don't confuse a comprehensive blood panel with an epigenetic-age test — that's a different product with its own limits, graded in biological age tests.)

Bottom line

Function Health's real value isn't the "100+ biomarkers" — it's the four or five cheap, outcome-validated markers (ApoB, Lp(a) once, hs-CRP, HbA1c) it surfaces that your standard checkup probably skips, plus the occasional treatable thyroid or deficiency catch. The rest is largely ordinary bloodwork dressed up by a big number, a correlated tail that adds little independent signal, and a couple of markers (IGF-1, homocysteine) that mislead as targets. Most important, it tests without treating: it flags problems it won't fix. Worth it for a motivated, health-literate buyer with a clinician who'll act on the results — a poor fit for anyone hoping a subscription is itself a health intervention. For an independently graded look at the labs and clinics selling these memberships, see our longevity clinic rankings.