Function Health explained: what $365 buys, what the evidence shows, real costs and alternatives

At a glance

Sources: Function Health FAQ, Function homepage, Function Terms of Service (last updated October 7, 2026). Checked November 2, 2026.

BML's short verdict. Function is a low-cost way to get a very broad set of lab tests twice a year, with a dashboard that long-term members rate highly. It is lab access with explanations, not a doctor: the people most disappointed are those who expected a consultation. The individual markers that matter most for longevity (ApoB, Lp(a), HbA1c and a few others) are well supported, but the evidence that screening healthy people with a very large panel improves outcomes is weak, and more tests mean more borderline results to chase. The service problems members report sit around the tests: missing Quest orders, slow support, a narrower mid-year retest and renewals that are hard to undo.

• Likely to suit you if you've never had a broad panel, you want markers your doctor doesn't routinely order (ApoB, Lp(a), fasting insulin), you'll take the results to your own doctor, and you'll actually use both draws.
• Probably skip it if your doctor already orders the markers you care about (often covered by insurance), you want someone to interpret results and manage follow-up with you, you're likely to be worried by borderline results, you live in Rhode Island, Hawaii or Puerto Rico, or you want to retest specific markers on your own schedule rather than a fixed annual cycle.

How it works

Function is a technology company that sits between you, a laboratory and independent clinicians. It describes itself as "not a laboratory or medical provider" and says lab and medical services are provided by independent third parties (Function homepage).

1. You join and pay $365. Function says you'll see nearby Quest sites; some members say they only saw the locations after paying (see What living with it is like).
2. The annual visit. You book a fasting, morning draw at Quest, or a home draw. Function says it takes about 15 minutes and draws 35 to 85 mL of blood. Members with an active menstrual cycle and members in Arizona need two lab visits for the annual test (Function FAQ).
3. Results arrive in waves. Function says the first batch usually arrives within 48 hours. Specialty tests take longer, and long-term members report the written clinician notes arriving two to three weeks later, occasionally four (Heal Nourish Grow; Dann Berg).
4. The dashboard. Each marker gets an explanation, a range and action items. There is a written clinician summary, a "biological age" figure and suggested protocols.
5. The mid-year visit. 3 to 6 months later, a smaller 60+ test draw tracks changes. It must be used before your renewal date and doesn't roll over.
6. Optional extras. On-demand tests for individual markers, add-on panels, the Galleri cancer test, and MRI or CT scans through Ezra, which Function bought in May 2025.
7. Connected apps and AI. Results can sync with Apple Health, Oura, Fitbit, Garmin, Withings and Peloton, and members can connect ChatGPT, Claude or Perplexity, or use Function's own Private AI Chat (Function FAQ).

Who does what with your results

This is the part of the service most worth understanding before you buy, because Function's marketing ("Clinicians review every result and flag issues") and its legal terms describe different things.

Sources: Function FAQ, Function: release of lab results, Function Terms of Service, NPR, Apr 14, 2026.

What that means for you. Plan to take anything abnormal to your own primary care doctor. The most positive member stories BML read follow exactly that pattern: Function finds a marker, the member's doctor orders the follow-up. A University of Pennsylvania ethicist quoted by NPR raised liability questions about companies that describe themselves as platforms connecting patients to physicians.

What is measured and what is calculated

Why biomarker counts are hard to compare. In January 2026 Function sued Superpower in federal court in California for false advertising, alleging that only about 55 of the "100+" biomarkers Superpower advertises are direct lab measurements and the rest are calculated ratios or indices (Athletech News). The parties told the court on June 12, 2026, that they had settled; the case was dismissed with no ruling on the merits and the terms weren't made public (court docket). The allegations were never tested in court. The point for buyers is that headline counts from any provider, Function's included, can mix measured markers, calculated ratios and repeat draws, so compare the marker lists rather than the totals. Our Function vs Superpower marker table does that for the two.

What the evidence shows, claim by claim

Several individual markers on Function's panel are well supported for estimating heart and metabolic risk, but no study has tested whether Function's program (or any similar broad, repeated panel) improves health in people without symptoms, and general health checks have a poor track record in randomized trials. These are separate questions, and evidence for one doesn't answer the other.

1. Do the individual markers matter?

Some clearly do. Function's panel includes markers that standard annual physicals often skip but that guidelines or major consensus statements support:

• Lp(a) is largely genetic and raises cardiovascular risk independently of LDL. A European Atherosclerosis Society consensus statement recommends measuring it at least once in every adult's lifetime (Kronenberg et al., European Heart Journal, 2022). In BML's review sample, one member's high Lp(a) led their own doctor to order a coronary calcium scan.
• ApoB counts the particles that cause atherosclerosis and can flag risk when LDL cholesterol looks normal.
• HbA1c and fasting glucose are recommended by the US Preventive Services Task Force for diabetes screening in adults aged 35 to 70 with overweight or obesity.

For these, the value is in measuring once (Lp(a)) or periodically, then acting with a doctor. You don't need a membership to get them, but many doctors won't order them without a reason.

2. Does broad, repeated testing improve outcomes for healthy people?

Not demonstrated, and the closest evidence points the other way. A Cochrane review of 17 randomized trials found general health checks in adults had little or no effect on deaths: the mortality analyses covered 11 trials and 233,298 people, with high certainty for total and cancer deaths and moderate certainty for cardiovascular deaths (Krogsbøll et al., Cochrane, 2019). Those checks weren't the same as Function's panel, and none used today's markers, but they are the best randomized evidence on "test healthy people broadly and see what turns up".

BML found no published study evaluating Function's program itself: no trial of members' health outcomes, false-positive rates or follow-up costs. Function's own figures (members, data points, conditions "detected") are company-reported.

Mainstream doctors quoted in independent reporting are skeptical of the frequency. A Northwestern internist told NPR that annual or more frequent broad testing isn't the standard of care for healthy adults; he follows guideline intervals such as cholesterol roughly every five years (NPR). In TIME's 2024 review, a Northwestern cardiologist estimated at least half the markers are routine labs, and a preventive-medicine physician warned that chasing incidental findings can be costly and stressful (TIME).

3. What are the downsides of testing more?

More tests mean more results outside the reference range by chance. A reference range typically covers 95% of healthy people, so across 100+ markers some "abnormal" results are expected in a healthy person. The TIME journalist who tried Function had 20 of 105 results out of range (TIME).

The risk is a cascade: a borderline result leads to repeat tests, specialist visits and sometimes invasive procedures. The NPR piece cites research finding that a third of such cascades started with a test that wasn't clinically appropriate in the first place. Function's mid-year retest and on-demand tests can help separate noise from a real trend, which is a point in its favor; your doctor's judgment on what's worth chasing is still the main safeguard.

4. The optional full-body MRI

Function sells MRI and CT through Ezra. Our Prenuvo deep dive covers what whole-body MRI finds in people without symptoms. The American College of Radiology does not support total-body MRI screening for people without symptoms, risk factors or family history, citing no evidence that it extends life and concern about incidental findings driving unnecessary follow-up (ACR, 2023). Function's own imaging terms say scan results aren't a diagnosis. The lung CT and coronary calcium CT Function offers are different: both have guideline-defined uses for specific groups (lung CT for older people with a heavy smoking history; calcium scoring when a heart-risk decision is uncertain), which is worth discussing with your doctor before buying.

5. The optional Galleri cancer test

Galleri looks for signals of many cancers in one blood draw. In the NHS-Galleri trial of over 142,000 people aged 50 to 77, the main goal (fewer stage 3 and 4 cancers combined) wasn't met; a secondary analysis showed more than 20% fewer stage 4 cancers, and just over half of people with a positive result were found to have cancer. Whether it reduces cancer deaths isn't known yet (UCL, Jun 2026). An FDA advisory panel voted in favor of approval for adults 50 and over on September 23, 2026, as an addition to, not a replacement for, standard screening (OncLive); BML found no final FDA decision as of November 2, 2026, and TRICARE's Galleri page says the test isn't currently FDA-approved (TRICARE).

6. Longevity claims

No study shows that a Function membership extends life or prevents disease. Function's marketing talks about detecting changes "before symptoms appear"; that is plausible for specific markers but hasn't been tested for the program as a whole.

Evidence summary

"None found" means BML found no qualifying study as of November 2, 2026, not that the claim is false.

What it really costs

The membership is $365 a year, but realistic spending depends on add-ons, where you live and whether the price holds at renewal. Function's terms say renewals are charged at "Function's then-current price"; the figures below assume today's prices.

Scenarios

Membership price: Function FAQ. MRI member price: Function imaging page and Ezra, both showing $999 reduced to $899 for Function members. Function's FAQ lists $999 as the member price, so Function's own pages disagree. Checked November 2, 2026. Galleri price: Heal Nourish Grow (not shown on Function's public pages). One independent reviewer puts a realistic first year with an add-on and a consult at $750 to $1,200 (Longevity Benchmark).

Not included above

• New York and New Jersey lab fees. Function's terms say lab testing fees are billed separately in NY and NJ, and its FAQ says testing there "can cost more due to state regulations". Function doesn't publish the amount anywhere BML could find; one comparison site says members learn it at the draw (TestWell).
• Extra markers. Single markers can be added on demand at a member price Function doesn't publish; reviewers report $19 to $49 per marker (Heal Nourish Grow). This matters because some key markers are only in the annual draw (see below).
• Add-on panels: extended heart and metabolic, hormone, thyroid, nutrient, immune, brain injury and degeneration, toxins, allergies and sexual health. Prices aren't shown on Function's public FAQ.
• At-home draws: offered, price not published.
• Follow-up care: any doctor visits, imaging or specialist referrals that results lead to are outside the membership and go through your own insurance.

What the mid-year retest covers

The mid-year visit is 60+ tests, not the full 100+, and it expires at renewal. Function's FAQ says it "must be used before" your annual renewal and doesn't roll over, and its terms say unused testing "will expire". Function's What we test page marks the markers it tests twice a year with "2x". Those include the lipid panel, ApoB, hs-CRP, HbA1c, glucose, insulin, the blood count, most liver and kidney markers and urinalysis. Markers without the 2x label include Lp(a), LDL particle number, thyroid tests (TSH, free T3 and T4, antibodies), sex hormones, PSA, vitamin D, ferritin and iron, omega-3s and GGT. If you're tracking one of those after a change in diet or medication, budget for an on-demand retest.

Price history

Function launched at $499 a year and cut the price to $365 on November 20, 2025, for new members, renewals and gifts (Function). Reviews written before late 2025 quote the old price. Function's page describes $365 as first-year pricing in some places and as the renewal price in others; the terms say renewal is at the then-current price.

Paying with HSA/FSA

Function says the membership and scans are HSA/FSA eligible, subject to your plan, and that you need the itemized receipt from your account's payment history rather than the card receipt. Check with your plan administrator first.

Function or your own doctor

Function costs less than buying the same breadth of tests one at a time. But the markers guidelines most often act on are either covered as preventive care or cost well under $100 each to buy directly, so the real question is which markers you'd use and whether your doctor will order them.

What routine care already covers. Under the Affordable Care Act, most US health plans cover a short list of lab screenings with no copay when done in network: cholesterol for adults of certain ages or at higher risk, type 2 diabetes for adults 40 to 70 with overweight or obesity, hepatitis C for adults 18 to 79 and HIV for everyone 15 to 65 (HealthCare.gov). The USPSTF now recommends diabetes screening from 35, so check what your plan uses. Other tests your doctor orders usually go through insurance, subject to your deductible.

Prices: Labcorp OnDemand list prices (some were 25% off when checked) and Quest, checked November 2, 2026. Mid-year column: Function's What we test page.

BML's reading. If you'll use the breadth and both draws, Function is cheaper than assembling a similar panel yourself. If what you want is ApoB, Lp(a) and HbA1c, you can get them once for about $157, or possibly nothing if your doctor orders them. Lp(a) is largely genetic, so one measurement is usually enough, which makes it a weak reason to renew; ApoB, lipids and HbA1c are the markers Function's mid-year draw does repeat.

Before you join, ask your doctor whether they'd order ApoB and Lp(a) for you and whether your plan would cover them. If yes, you may not need a membership; if no, Function or a one-off panel fills the gap.

Membership terms, plainly

Source: Function Terms of Service, last updated October 7, 2026; Function FAQ. Checked November 2, 2026.

Three things buyers miss.

1. The refund window is 48 hours. After that, or once blood is drawn, the year is paid for. Renewals can't be refunded, so set a reminder before your renewal date.
2. The mid-year draw expires. If you don't book it before renewal, it's gone, and it's a smaller panel than the first.
3. There's no doctor visit. You get a written summary and a call only for critical results. Budget time with your own doctor for anything that needs follow-up.

What living with it is like

Members consistently praise the breadth of the panel, the dashboard and Quest scheduling; the complaints are about lab handoffs, support, the mid-year retest's scope, generic clinician notes and billing. The patterns below come from a coded sample of public reviews, so they show what comes up often, not how common it is among all members.

What reviewers say, by theme

A review analysis prepared for BML on November 2, 2026, coded 340 Function reviews and comments: 148 from Trustpilot, 174 from Reddit and 18 from expert or blog reviews. The coding is approximate and machine-assisted, and "mentions" means an item touches the topic, not that it complains about it; where spot checks separated complaints from other mentions, the table says so. One review can carry several themes.

How positive is it? Trustpilot items in the sample were 77% positive and 11% negative; Reddit items were 46% positive and 25% negative. Both lean: Trustpilot's default pages show recent invited reviews and its filtered views couldn't be read, while people post on Reddit more often when something goes wrong.

Long-term reviews

No review yet meets every one of BML's review rules (named writer and publication, dated, how they got it, stated time used) on the current $365 membership, so these are context, not a verdict on today's service.

Customer ratings

Function scores 4.5 out of 5 on Trustpilot from 3,106 reviews: 75% five-star and 6% one-star. Trustpilot shows Function replies to all negative reviews, usually within 24 hours, and invites customers to review (Trustpilot, November 2, 2026). The Better Business Bureau gives Function a B- with 71 complaints over three years, as reported by Agewell; BML hasn't checked the BBB page directly.

These ratings reflect ordering, scheduling and support, not whether the tests improve health, and complaint volume can't tell you a failure rate.

Practical checks before you join

• Your state: not available in Rhode Island, Hawaii or Puerto Rico; extra lab fees in New York and New Jersey. Arizona members need two lab visits.
• Your nearest Quest: check distance and whether it draws for Function outside early-morning slots. Members report long drives in rural areas.
• Before the visit: fast for 8 hours, book a morning slot, drink water, and download the lab requisition from your account in case Quest can't find the order.
• Your doctor: ask whether they'll review outside lab results. Some will; some won't.
• Your calendar: set reminders for the mid-year draw and a week before renewal.

Membership risks

The biggest risks are about what you can't easily undo or take with you: a year paid upfront, results that export only as a PDF, testing tied to one lab network, and health data that can flow to several partners if you connect them. Function's FAQ says its platform is SOC 2 Type II verified, "HIPAA-aligned" and encrypted, that access is limited to you, lab partners, clinicians and essential staff, that results may go to state health authorities where the law requires, and that using your health data for marketing needs your authorization. Deleting your data is permanent (Function FAQ).

How Function compares across the sector

Our Compare longevity tests page tracks 14 US blood-test providers, each checked on the provider's own site and dated. Set against that data, Function's price is middle of the pack, its two-draw structure is less unusual than it looks, and it says less than most rivals about who orders your tests and what NY/NJ members pay.

Ordered by first-year cost, not ranked. First-year cost is the sum of the parts each provider publishes (membership or test, required draw fees, required consults), from our compare data, checked October 9 to 31, 2026. "Not stated" means the provider doesn't say on the pages BML checked. Trustpilot scores were checked October 14, 2026, except where another date is shown.

What the comparison shows

• Price. Function's $365 is the fifth-lowest first-year cost of the 13 blood-test options with one, against a median of $399. It's the cheapest way in BML's data to get two broad draws at a fixed price, though only by $16: Ultrahuman's Annual Plan has the same shape (a 100+ test then a 60+ follow-up) from $349, a "from" price whose renewal isn't stated.
• Two draws a year is not unique. Three providers include two draws (Function, Ultrahuman, Lifeforce), OneTwenty includes four smaller ones and Rythm twelve. Lifeforce costs $234 more but includes a clinician consultation.
• Who orders the tests. Six of the 14 say their own physician network orders your test. Function is among the eight that don't say, which fits the gap in Who does what with your results.
• A consultation. Only Lifeforce and Marek include one in the price; Quest offers an optional call at no extra cost and Mito one for $39. Function, like most memberships, doesn't.
• NY/NJ transparency. Mito and OneTwenty publish what New York and New Jersey members pay, and Superpower gives $399 on its own comparison page. Function and Ultrahuman say only that it costs more.
• How tests are counted. No provider in BML's data says how many of its headline markers are calculated rather than measured. Function and OneTwenty both count repeat draws in their yearly totals; Superpower's and Everlywell's lists include calculated ratios and scores, and Function's settled lawsuit alleged that about 55 of Superpower's "100+" are direct measurements (see Why biomarker counts are hard to compare).
• Ratings. Function's Trustpilot score is among the higher ones in the sector, with one of the two largest review counts (Rythm's is similar). The lowest scores belong to the big labs, Quest and Labcorp, whose ratings cover all their customers, not just direct-to-consumer buyers.

How to choose. If you mainly want the guideline markers, ask your doctor first (see Function or your own doctor). If you want a broad one-off baseline, a single panel from Mito, Quest or Labcorp avoids a renewing membership. If you'll genuinely retest twice a year, Function and Ultrahuman are the cheapest fixed-price options. If you want someone to go through results with you, Lifeforce and Marek include a consultation.

BML evidence and ownership scorecard

Function scores well on cost and breadth, and poorly on evidence for the program and on its terms. BML uses labels rather than a single number, and keeps evidence confidence separate from performance.

Assessment basis: Function's own documents, published research, independent reporting and a coded review sample, not BML hands-on testing. Methodology version 0.1, November 2, 2026. Function had no input into these labels.

Company background and recent developments

Function Health is a privately held company based in Austin, Texas, founded in 2021 (Wikipedia) and launched in 2023 (Fierce Healthcare). Co-founders include CEO Jonathan Swerdlin and Chief Medical Officer Dr Mark Hyman, a functional medicine physician. Hyman is on our Longevity thought leaders page, which notes that he advocates extensive personal biomarker testing (100+ markers) and sells his own 13-product supplement stack. Both are commercial interests worth knowing when you read Function's protocols, which include supplement suggestions. NPR reported in April 2026 that Function has hundreds of thousands of members. Funding is context, not evidence that the service works.

Frequently asked questions

How we researched this, sources and updates

Method. BML reviewed Function's homepage, FAQ, Terms of Service and results-release form; independent research (Cochrane, the NHS-Galleri trial, ACR guidance, the EAS Lp(a) consensus); independent reporting (NPR, TIME); long-term member reviews; Trustpilot; and a review analysis that coded 340 public Function reviews and comments. Sources are labeled by type (company, independent research, independent reporting or third-party review) in the tables and evidence summary, and named next to each claim in the text. BML didn't test the service and didn't contact Function for this version. Prices and terms were checked October 31 to November 2, 2026. Function's price, test count and state limits match our Compare longevity tests page; when one changes, the other is updated too. This page was drafted with Claude, an AI tool, and figures were checked against their sources. No brand pays to be listed or for its position. How we choose providers.

Not medical advice. Nothing here is a recommendation for your health or an interpretation of anyone's results. If a result worries you, or you're deciding whether to test, talk to your doctor.

Updates