Function Health, Superpower and a physician-led practice: what each includes and how they fit together

What does each service include?

Each of the two lab memberships includes a large blood panel repeated through the year, written explanations of the results, and some form of clinician input. A physician-led practice includes the medical relationship itself. The descriptions below use each company's own words as of September 2026, and both change their offerings often.

Function Health describes what it offers as “160+ lab tests, doctor-reviewed insights, and a personalized health plan.” Its site states that “Clinicians review every result and flag issues” and that people receive “action items and a clinician’s full summary.” For urgent results it says: “If any result is critical, a healthcare provider will call you right away.” Results can be downloaded and shared with a person's own clinician. The company also describes itself as “a healthcare technology company and not a laboratory or medical provider” and recommends that people with questions about results “discuss those questions with a primary care physician or other licensed provider.”

Superpower says: “We test 150+ biomarkers annually across two blood draws.” It adds that “Superpower AI and your care team help you take action across lifestyle, supplements, and treatments” and describes its support as “AI for everyday health questions. Real clinicians for added one-on-one support.” Its FAQ says the service “specializes in prevention-based testing and treatments and is not intended for emergency or immediate health issues” and that it is “designed to complement a primary care doctor if you have one, not replace them.” It also offers to help share results with an outside provider.

The two overlap more than they differ. Both draw blood through a national laboratory network or at home, both retest during the year, and both return a written plan. They differ mainly in emphasis. Function Health points to imaging, saying people can “Add MRI and CT anytime”; Superpower points to connected data, saying people can “Upload past labs and sync your wearables.” Which emphasis suits a person is a matter of preference, and neither description is a measure of quality.

A physician-led practice is organized around a person, not a panel. It includes a full history and, where needed, an examination; the authority to diagnose; decisions about treatment, including medication when it is warranted and the choice not to treat when it is not; referrals and coordination with specialists; and a physician who stays accountable for whether the plan worked. Testing is part of it, chosen for a reason each time. Extend Medical is a practice of this kind: private-pay, not billed through insurance, with care that starts from the person's history.

Is a lab membership worth it?

It depends on what happens after the results arrive. A lab membership is worth the most to a person who has somewhere to take the findings, and worth the least when a long report leads to worry with no outlet, or to nothing at all.

The case for one is straightforward. Broad testing can surface something nobody was looking for: low iron stores, an early shift in blood sugar regulation, thyroid antibodies, or a high level of Lp(a), an inherited cholesterol-carrying particle that a standard lipid panel does not measure. Repeat testing builds a baseline, and a baseline is what makes a later change visible. For many people, seeing their own numbers is also what prompts a change in how they eat, sleep and train, and a way to check whether it worked.

The limits belong to broad testing itself, not to any one company. Reference ranges are drawn to include about 95 percent of healthy people, so the more markers a panel measures, the more likely a well person is to see a flag: by one calculation, the chance that every result lands in range is only about 60 percent with ten independent tests [PMID: 15327009]. Some flags fade on a repeat draw. Others are real and lead to an examination, a confirming test, imaging or a treatment decision, which is where a person's own physician comes in, as both companies say themselves.

So the useful questions are personal ones. Is there a physician who will read the report against the person's history? Are the results likely to change what the person does or the care they receive? Would a smaller set of tests, chosen for a reason, answer the same question? None of these has a universal answer, and reasonable people land in different places.

How does a physician-led practice fit with a lab membership?

The results are reviewed as part of care. A physician reads the report against the person's history, medications and earlier results, decides which findings need confirming and which need nothing, and folds what is real into one plan that someone is accountable for.

In practice that means a few concrete things. Flags are sorted into those that reflect the conditions of the draw, those worth repeating, and those that open a focused workup. Markers are read in clusters, because triglycerides, a liver enzyme and fasting insulin moving together say more than any one of them alone. Decisions about treatment are made against the whole picture and the person's goals. When a finding belongs to a specialist, the referral goes with the context attached. The detail of how a physician reads a large self-ordered panel follows the same logic.

The testing itself changes shape over time. Once a baseline is known, the next round is chosen by what would change the plan, which may be a narrower set than the first panel or a different kind of test altogether, such as imaging or a sleep study. A physician-led practice can work alongside a person's primary care physician and specialists, and coordinate with them, so that results from every source are read as one record. Some people keep a lab membership for the routine draws and bring each report to their physician; others find that testing ordered within their care covers what they need. Both arrangements work.

What is worth bringing to a physician?

The full report, not the summary. That means every marker with its units and reference range, the date and time of each draw, and whether it was fasting. Results from a service a person ordered on their own are reviewed as part of care, and a few other things make the reading sharper:

• Earlier labs from any source, even from years ago, so that a trend can be told from a snapshot
• A list of medications and supplements, including biotin, a B vitamin that can interfere with some laboratory methods [PMID: 40417451]
• The family history, especially early heart disease, diabetes, cancer and dementia
• Any imaging or screening reports, such as a coronary calcium score or a whole-body MRI report
• The plan the service generated, since it shows what has already been tried
• The question that prompted the testing, because the reason for a test shapes what its result means

Which results should not wait for an appointment?

A result the laboratory labels critical should not wait for a routine appointment. Laboratories phone these through, which is why a person may hear about one by telephone before the report is ready. A critical result, or any abnormal result that arrives with chest pain, trouble breathing, fainting, confusion or sudden weakness, is a reason to seek prompt care: call 911 or go to the nearest emergency department.

The deeper picture

Measurement has become easy to buy, and that is mostly good: more people know their numbers, and more problems are found while they are still small. What has not changed is that a number becomes useful when someone weighs it against a history, decides whether it is signal or noise, and stays to see whether the response worked. The two ways to get it wrong are symmetrical: acting on noise until a healthy person feels like a patient, and missing a slow drift because every value was still inside its range. Steering between them takes physician-level clinical rigor and time with one person's whole picture, whichever laboratory the numbers came from.