Function Health Reviews: What It Does Well, and Where It Stops

Function Health is a membership for lab testing. You pay annually, get tested twice a year, and receive results with clinician review and an action plan, without needing a physician referral or an insurance claim.

• 160+ lab tests annually, covering hormones, metabolic, cardiovascular, thyroid, nutrients, inflammation and more.
• Tested twice a year, with on-demand testing available.
• Draws at 2,000+ locations, or an at-home phlebotomy option.
• Clinicians review every result and flag what needs attention.
• MRI and CT imaging can be added separately.

For context: Function says a standard annual physical runs about 26 markers. The Protocol MD comprehensive bloodwork panel runs 70+ markers. The gap between those numbers and 160+ is the whole product, and it is a real gap. For what individual markers mean, MedlinePlus's guide to lab tests from the National Library of Medicine is a neutral reference.

Function Health testing works as a simple step-by-step process, and a surprising share of the onboarding complaints in the reviews trace back to details that sit in its own FAQ. Here is the sequence as Function describes it, checked on its site in October 2026.

• Join and schedule. Membership is open to adults 18 and over who are not pregnant. You book a draw at one of 2,000+ Quest locations in 48 states; Function lists Rhode Island, Hawaii and Puerto Rico as not yet covered.
• Prepare. Function asks for an 8-hour fast and a morning draw, because testosterone and cortisol read most accurately early in the day. It notes that biotin can interfere with hormone and thyroid markers and that some members pause it 72 hours ahead, and it asks members to avoid seafood for 48 hours before the heavy-metal tests.
• The draw. About 15 minutes, and roughly 35–85 mL of blood depending on the person. A typical blood donation is around 500 mL. Members with an active menstrual cycle need two visits so the hormone markers are timed correctly.
• Results. Function says the first results typically start arriving within 48 hours, with plain-language explanations, action items and a clinician summary. A critical value triggers a call from a healthcare provider.
• The mid-year retest. The annual visit covers 100+ tests. A follow-up of 60+ markers runs three to six months later, must be used before renewal, and does not roll over.

Two policies explain a share of the negative Function Health reviews on their own. Function does not refund prior payments, and it does not allow a membership pause; you cancel and rejoin. None of that is hidden. None of it is on the homepage banner either. The testing steps themselves are simple; the policies around them are where members get caught out.

Function Health's included panel tests a broad range of markers, and several tests are not included. Per its FAQ, the 160+ annual tests cover heart, hormones, thyroid, liver, kidneys, nutrients, inflammation, autoimmunity, electrolytes, metabolic markers such as hemoglobin A1c and insulin, and mercury and lead.

Cardiovascular coverage goes past a standard lipid panel to apolipoprotein B, lipoprotein(a) and lipoprotein particle size. Function's own example of why that matters is ApoB, which can point to cardiovascular risk when a routine cholesterol result looks normal. That is the kind of marker a 26-test physical usually leaves out.

What is not in the membership

Several things readers assume are in the membership are add-ons: the Galleri multi-cancer blood test, an ApoE test tied to Alzheimer's risk, allergy and sexual-health panels, extended hormone and thyroid panels, and arsenic and aluminum. MRI and CT scans are not included either.

Where the standard panel is deliberately narrower

The standard panel is deliberately narrower for members on hormonal birth control: Function does not run FSH, LH or estradiol, because the pill skews those results. That is the clinically sound call. It also means a woman on the pill will not get a full sex-hormone picture from the standard panel.

Function also states that its member support does not give medical advice. It explains results; it does not diagnose or prescribe. That one line is the root of most of the "now what?" reviews below.

Most of what people praise in Function Health reviews holds up.

The reports are readable

Reviewers consistently say the reports are readable, with results presented in plain language and optimal ranges rather than just the lab's reference range — which is the difference between a number and a piece of information.

It finds things

Function finds things: many reviews describe a marker nobody had checked before turning up out of range. That is what broad screening is for, and a standard 26-marker physical would not have caught it.

Function Health reviews turn negative over a tight cluster of complaints, and they are mostly not about the testing.

"Now what?"

"Now what?" is the recurring complaint across Reddit and Trustpilot. You get a large amount of data, a clinician note and a protocol — and then you are on your own to find someone who will act on it. If three markers are off, you still need a prescriber, and Function is not one.

It is a subscription

It is a subscription, so the annual charge recurs. Some reviewers signed up for a baseline, got their answer, and were surprised by the renewal. If you want a one-time workup, a membership is the wrong shape of product.

Breadth can create anxiety

Breadth can create anxiety: test 160 markers and something will come back flagged; that is statistics, not illness. Without someone to tell you which flags matter, a wide panel can generate more worry than it resolves — a known tradeoff of broad screening, not a flaw unique to Function. Our guide on how to read blood test results explains why a flag outside the reference range is not automatically a problem.

Protocol MD sells a different shape of thing from Function Health, and it is not better across the board.

Read that table honestly and Function wins on breadth and on cadence. If what you want is the widest possible picture, buy Function.

The row that actually separates them is the second from the bottom. Function tells you what is wrong. A prescribing clinic can also do something about it.

Function Health fits people who want broad data, and a prescribing clinic fits people who want treatment for what the labs find.

Function Health makes sense if

Function Health makes sense if you want broad data and already have a way to act on it:

• You are broadly healthy and want a wide baseline you can track over years.
• You already have a physician who will act on the results.
• You want imaging available in the same place.

A prescribing clinic makes more sense if

A prescribing clinic makes more sense if you want the person reading your labs to treat what they find:

• You already have a symptom (fatigue, weight that will not move, low drive, poor sleep) rather than a general curiosity.
• You want the person reading the labs to be the person who can treat what they find.
• You do not want a recurring membership.
• You would rather have 70 markers and a plan than 160 and a PDF.

These are not mutually exclusive. Plenty of people test broadly once, then take the results somewhere that can act on them.

Yes, Function Health is legit. It is a real company running real tests through Quest Diagnostics draw sites, with clinician review of results. The questions worth asking are not about legitimacy.

They are: do you want a subscription or a one-time panel, and do you have somewhere to take the results. Most of the disappointment in the review corpus traces back to one of those two, not to the testing itself.

Function Health answers what is going on inside you; the question worth asking before you pay is who is going to do something about the answer.