The healthcare system in the United States sucks for a multitude of reasons. At its core, many of these issues stem from a system that disempowers both patients and doctors. For-profit insurance companies act as middlemen, often making essential care unaffordable—or completely out of reach—by overruling the decisions of highly trained physicians.

In January, I signed up for a service that feels like a revelation: Function Health. For $500 per year (plus a few hundred dollars for lab work, depending on your state), Function Health provides access to over 100 blood tests that would otherwise be nearly impossible for the average person to obtain. The results are then delivered in a “first-of-its-kind” Health Dashboard.

Now that I have all my test results back, plus detailed clinician notes, I feel more empowered regarding my health than ever before. Plus, I’m more motivated than ever to make lifestyle/diet changes, since I know I can check in on these numbers regularly.

In the system we have today, people need to be their own health advocates. That means keeping track of your own health data and verifying its accuracy, getting second opinions as necessary, and ensuring different doctors are sharing information with each other. Doctors are human and can make mistakes and our system is imperfect. No one will care about your health as much as you.

This article is both an explanation of my reasons for joining Function Health as well as my experiences with the platform. I am a full-price paying customer myself and this is my honest review.

If you found this article interesting and decide to try Function Health yourself, you’re welcome to use my referral link to skip the waitlist. Full transparency: the “waitlist” is mostly a startup growth tactic, and you can also bypass it by filling out a quick survey without using my affiliate link. But my link is a great way to say “thank you” if you enjoyed this article. Completely your choice.

Let’s start zoomed out and talk about how I see a service like Function Health fitting in to my life.

My general life philosophy

My general life philosophy boils down to two principles:

1. Find the minimum amount of effort that outputs the greatest results
2. Identify experts in various fields, and use their vast experience to drive my actions and decision making

If I’m interested in a new topic, I’ll look for a single book or article that’s well-respected in that area. By reading that content, I’ll gain the greatest amount of knowledge with the least amount of effort, relying on the expertise and research of the author to reap the greatest knowledge gain.

A recent example might be The Order of Time by Carlo Rovelli, a fantastic dive into science’s current understanding of time as a part of quantum physics. Another example would be Wirecutter, the product review website owned by the New York Times.

This is also why I’m so drawn to Bryan Johnson, the tech entrepreneur spending millions to reverse his aging. He publishes all his data as part of Blueprint, a health and longevity experiment where he boils down his plethora of research into specific action steps for others to follow. Readers can reap the benefits of his millions of dollars of testing and research without spending the same level of money themselves.

The foundation of all these experts is data and transparency.

As I near my 40’s, I’m thinking more and more about my health and fitness related goals that will carry me through the second half of my life. To that end, I want to identify the minimum effort that will provide the maximum benefits towards achieving these goals. And I want it to be backed by data.

And that brings us back to Function Health, a service I feel provides exactly that.

Before Function Health

I’ve been getting an annual-ish Physical since my mid-20’s. Part of these physicals is blood work, which is typically the most enlightening part of these exams.

In 2023, my Lipid Profile results showed a few components that were out-of-range: Cholesterol, LDL Cholesterol (Calc), and Non-HDL Cholesterol. These numbers weren’t dramatically high, but they were something I knew I wanted to address, despite a followup note from my doctor saying he wasn’t actually concerned with these results.

For the next few months after the test, I made some minor dietary changes that I hoped would help address these numbers. Then, my motivation waned and my healthy eating habits slipped. Throughout the year, I’d slip in and out of these positive habits, never knowing if they were actually impacting my Cholesterol levels or not.

A year is a long time to stay motivated when there are no indicators of positive progress. I don’t feel any difference when my blood markers are in range versus out of range.

Blood test results feel important when you get them, but urgency dissipates as the year progresses. That, paired with a lack of concern from the doctor, makes it easy to slip into past habits.

Despite these hurdles, my 2024 blood tests showed only one component out-of-range: LDL Cholesterol (Calc). I felt accomplished, but also more in-the-dark than ever. I felt zero difference in my day-to-day life, so what else might be out-of-range but could be easily fixed with minimal effort?

Joining Function Health

The main value proposition of Function Health is access to over 100 blood tests that are typically unavailable to the average person.

From their FAQ:

The traditional insurance route typically requires a specific symptom or condition to warrant comprehensive testing. (We find it backward to require the existence of a condition to test for that same condition.)

To get all the tests included in your Function membership, you would need to work with a doctor willing to request these 100+ tests. Doctors rarely have the time needed to review this many tests, let alone to understand and explain your results to you. They also want to avoid creating financial burdens on their patients who may be billed for any advanced lab tests. You would also likely miss out on insights from the world’s top doctors based on your specific results.

The company’s medical team curates tests they judge to be “both valid and important for revealing the deepest understanding of your health.”

This perfectly matches rule two of my general life philosophy: utilizing expert opinion to drive my actions and decision making. I’m not a doctor and have no idea what blood tests are helpful in determining overall health. It is appealing to me to have access to this thoughtfully-picked collection of tests that could provide the biggest bang for my buck.

Signing up is a two-step process: first, you need to join Function Health and pay the $499 annual cost, then you need to find a place to get your blood drawn.

The first part is super easy—Function Health will gladly take your money with only a few clicks. When you join, you also take an intake survey that asks about your primary health goals and reasons for joining.

The second part was also super easy for me, as a resident of Downtown Brooklyn. There is a Quest Diagnostics within walking distance from my apartment, allowing me to pop in and get my blood drawn with very little effort.

In terms of timeline, here was my experience with the platform:

• January 11th: Signed up for Function Health and paid the $499 fee
• January 20th: Blood draw 1 of 2
• January 21st: First results appeared on my Dashboard
• January 24th: Blood draw 2 of 2
• February 17th: Clinician Notes available

This first blood draw set is the first half of what’s included in an annual Function Health membership. Six months after this initial test, you have a second round of tests to check your progress in each category. Additionally, you can retest any of these biomarkers at any time throughout the year for an additional fee.

I joined Function Health three months ago, so I’ve only done this first round of tests. I plan to do my next round in another three months, but wanted to write up my experiences so far.

Let’s dive into the details.

The drawing of the blood

Function Health membership includes two sets of tests over a 12 month membership period: 100+ lab tests at the start of each year of membership, and 60+ lab tests 3-6 months later to see what’s changing.

Performing 100+ tests requires a lot of blood, at least compared to your typical annual physical. That means the initial test is split over two visits, spaced within ten days of each other (I scheduled my first on a Monday morning and the second on the following Friday morning).

Each visit took ten vials (compared to two vials taken at my annual physical). Function Health, however, is quick to put this amount into context:

35mL of blood is typically drawn at one time to keep things easy. For context, a blood donation is 14x more at ~500mL.

That means each blood draw took 5x more than my annual physical but 14x less than a standard blood donation. I did find that knowing these numbers helped with the mental aspect of the blood draw.

Function Health has very specific instructions to help members prepare for their blood draw:

1. 72 Hours Before, stop taking supplements. Many common supplement ingredients can interfere with your results. However, you should continue medications as prescribed by your doctor.
2. 48 Hours Before, start avoiding seafood before your lab visit. You will be tested for mercury.
3. 8 Hours Before, start fasting. Be sure to eat a light, healthy meal before you start your fast and avoid drinking alcohol. After that, no food or drink for 8 hours, which includes black coffee in the morning. The one exception is water, and we recommend drinking plenty of it before and after.
4. Morning of Visit, drink at least 1 liter of water before your lab visit, because good hydration makes blood flow faster. And don’t exercise until after your lab visit.

I followed these instructions dutifully, although I forgot about the seafood fast and had a piece of fish three days before my test (outside of the recommended 48 hour window, but I was trying to avoid it more broadly). More on the impact of that slip up later.

Also, you’re specifically instructed not to provide insurance to the lab testing facility, even if you have insurance. Looping in your insurance company negates the special pricing that Function Health negotiates on members’ behalf.

When I arrived at Quest Diagnostics, I signed in on their iPad scanned my photo ID, and sat in the lobby to wait to be called. It took about ten minutes.

Once I got into the blood draw room, the phlebotomist reviewed my information and I confirmed that I was there as part of Function Health. She commented that Function had been getting more popular recently, and this location now gets about five members per week as part of this program. Good job, Function Health! That piece of information alone made me feel more confident in my decision to join. Thank you, social proof.

I then had to pay Quest Diagnostics for their services: just over $200 for each of the two visits. This is on top of the Function Health cost, and the price varies from state to state.

The blood draw itself was uneventful. The phlebotomist prepared ten vials, tied off my arm, and inserted the needle. Then she filled each vial up one by one, all while making conversation with me to try and distract me from the unpleasantness (which was appreciated).

The blood draw itself took maybe three or four minutes total. Then I was on my way.

Initial results started appearing in my portal the next day, approximately 28 hours after my appointment.

That first blood draw was on a Monday morning and I had my second appointment of that series the following Friday morning. That second appointment was almost exactly the same as the first, with the addition of a urine sample collection.

The results

As I mentioned, initial results started appearing in my Function Health portal the day after the initial test. I got an email notification when those first results were available, but no further notifications as additional tests drip dropped into my account.

I found it easier to check my results on my phone, although the same information is all available on their website as well.

When you open the app, you’re greeted to a summary of your results, the numbers in which update as the tests are completed.

For every test, you can see your results as compared to the optimal range.

Each biomarker also has a detailed description in a section titled “Why it matters?” (sic). This provides information about the function of each biomarker, what impacts the biomarker, as well as the consequences of being out-of-range.

Did I use all of this information? Definitely not. The sheer amount of information about each marker feels overwhelming.

But I understand why it needs to be there. If you search Google (or Kagi!)for any individual one of these biomarkers, you’ll get a barrage of information to sift through. Some of it will be more accurate than others. Instead, having a one-stop-shop for results and information about said results is the ideal UX design.

At the bottom of the Function app home screen is a summary of all your results by category. It’s easy to see how you’re doing in each.

The very first out-of-range biomarkers that started coming in were all related to Male Health: Estraiol (E2), Follicle Stimulating Hormone (FSH) and Sex Hormone Binding Globulin (SHBG). These were each barely over the threshold, and further reading said that these can be effected by the exact type of fish I had three days earlier. Phew.

Clinician notes

Having this abundance of raw data is all well and good, but it’s really the expert opinion that’s the true value of this service. As you can see, I have several biomarkers that are out-of-range, but it’s hard to know which ones are urgent and which ones matter less. Twenty eight days after my initial test (exactly four weeks) I had my clinician notes available in my dashboard.

This is the meat of membership—the thing we’re paying for. More than the raw data, this is the action plan. But also, this sort of data is only as valuable as one’s ability to use it to make positive changes.

By the time the physician’s notes arrive, you’ve had time to watch each biomarker result roll in and research your deficiencies on your own. You’ve tried your best to read the tea leaves yourself using the generic information that Function Health provides. This note sheds light on the aspects of your health you’re already thinking about.

For me, these notes are worth the cost of membership. It feels like the type of information and advice I always wanted to get from my doctors, but never did.

The clinician’s note contains a summary section followed by details specific to each category. The summary is particularly useful, since it hits on all the same points that you’ve been wondering about (worrying about?) yourself. The summary section text feels totally personalized, with only touches of stock phrases that really just serve to ensure accuracy and professionalism.

For my clinician report, this summary section was split into three paragraphs totally 415 words. The first section touched on the areas requiring attention as well as biomarkers that were out-of-range but aren’t actually worrisome. The next section is the positives, and how each tie together to make a greater whole. The final paragraph is an overall summery with specific action steps.

The category-specific sections of the physician’s note is also personalized, but much more generic feeling (especially in categories where there are zero out-of-range biomarkers. Personalization comes from the note mentioning specific goals of yours from your intake survey, which means the clinition actually read my responses.

For categories with biomarkers that are out-of-range, the clinician notes provide detailed context for these results and how each component impacts the others to tell a broader story. These include possible recommendations for diet change or supplements to consider, with a disclaimer that all changes should be discussed with one’s doctor.

“Your Action Plan”

There’s a section of the app/website adjacent to the clinician notes called “Your Action Plan.” This section is currently marked “ALPHA”, implying that this feature is in a preliminary stage and subject to change and updates. Function Health needs to walk a find line with this section, in the same way a lawyer might say “this is not official legal advice” before providing their thoughts.

The fine print at the bottom of the Function Health website makes it clear that all information provided is “strictly for general information purposes” (captured March 8, 2025):

Function health does not offer medical advice, laboratory services, a diagnosis, medical treatment, or any form of medical opinion, through our services or otherwise. Function health’s services are not a substitute for medical care, medical advice, and/or a detailed discussion with your primary care physician or other licensed provider.

With that legalese expressly stated, the Your Action Plan section includes both foods and supplements to enjoy and limit. Each section shows a personalized “top five” followed by a long tail of other substances in each category.

While these recommendations are personalized based on your specific test results, I imagine they remain relatively similar for all members. But it’s a nice reminder of changes one can make in order to improve one’s results for next time.

Overall, I found this information useful and have started incorporating minor adjustments into my diet. I’ll be interested to see how these changes impact my results in subsequent follow up tests.

Changes I’ve made

Joining Function Health was part of a larger goal of being healthier and more active in 2025. It’s being paired with tracking my caloric intake in Lose It! and tracking my weight in Happy Scale.

So far, three months into the year, I’m still on top of all my health-related goals. I’ve lost roughly ten pounds so far this year, which is more than half way towards my goal weight.

What role did Function Health play towards this achievement? It’s hard to say. But I’m definitely still actively thinking about my results and the recommendations and I’m excited to get my followup tests in another three months.

There are two main components that occupy brain space as a direct result of Function Health: heart health and the need for supplements.

My annual physical highlighted cholesterol as an area that needs focused attention, but the followup test showed things had improved. Function Health told me that this is still a good area to focus my energy, since seven of the fifteen Function Health heart biomarkers were out-of-range (compared to one out-of-range from my annual physical blood work). I’ve cut red meat out of my diet entirely and am trying to eat more heart-healthy foods.

I also have started taking taking some daily supplements, including Bryan Johnson’s Longevity Mix and Nordic Naturals Ultimate Omega. The desire to add both of these to my diet is a direct result of my Function Health results.

I’m feeling optimistic about sticking with these new habits. A strong motivator, for me, is my access to follow-up tests through Function Health to see if any of my biomarkers improve over time. I think it’s super interesting to have hard data to support these behavioral changes.

Beyond that, however, life is still largely the same. Did I need to purchase Function Health in order to make these changes? Maybe not. But what I do know is that I didn’t make these changes before these tests, so it’s seems straightforward to attribute this to my membership.

The argument against Function Health

Last week, I had my annual physical. It was my first time seeing my primary care physician since doing Function Health, and I was excited to share my results with my doctor. I had them all pulled up on my phone, ready to share.

I was shown to my room by a medical assistant, who took my weight and blood pressure. I asked if she’d ever heard of Function Health, since the phlebotomists at Quest Diagnostics were definitely familiar with the company. She said she hadn’t.

I explained the value proposition: that it gives you access to over a hundred blood tests that typically aren’t available to patients. You can then test every six months to track your progress in each area.

She seemed skeptical but intrigued, though she had other work to do, so told me the doctor would be in soon and went about her business.

When my doctor arrived, I started to ask him the same question, but he stopped me before I could finish. He told me not to waste my money. In his opinion, patients having more and more access to tests like these is a huge problem, since totally benign conditions are suddenly perceived as significant problems that need to be addressed.

He told me the story of his rich friend who decided he wanted to get a full-body preventative MRI. This isn’t what Function Health does, but the value proposition of the two companies is the same: making typically out-of-reach medical tests available to paying customers.

My doctor encouraged his friend not to do the scan, saying it was totally unnecessary. But the friend was determined.

The full-body MRI discovered a cyst in his pancreas. He had no symptoms and his bloodwork was totally clean, but since they found the cyst, it had to be removed. He ended up in the hospital for five days due to complications with the surgery. It turned out the cyst was totally benign, and thus the procedure and accompanying risk were totally unnecessary.

After the story, my doctor emphasized that the blood tests he orders for his annual physicals are enough to catch important issues. When you test for everything, you’ll inevitably find something, and you can drive yourself crazy trying to fix things that don’t actually matter. Everyone’s body is different—some people will have naturally higher levels for certain biomarkers—and casting a net as wide as something like Function Health does more harm than good.

I pushed back, saying I was less interested in individual results than I was in the trends over time. I agreed that a full-body MRI is unnecessary, but having access to a time series of information on my own personal biomarker trends can be incredibly useful.

But his eyes were already glazed over, and I knew I wasn’t going to change anyone’s opinion. I had my normal annual physical exam and then my doctor was on his way to his next patient.

After he left, the medical assistant came back in for my blood draw. The first question she asked was how much blood Function Health needed to draw in order to do all these tests. I told her that it was two appointments with ten vials each.

She laughed, and said she couldn’t imagine her patients’ reactions if she had to grab ten vials for a blood draw. People have a hard enough time with two.

I told her about the doctor’s reaction, and that he didn’t seem to be a fan of the concept. She responded that she wasn’t surprised. “He’s old school,” she said. But she seemed intrigued and I wondered if she might look into the service after I left.

So, is Function Health worth it?

All the points my doctor made against Function Health are valid. I think there’s a fine line between collecting useful data and overanalyzing insignificant metrics. Just as I don’t think exploratory surgery on a healthy person is useful, so too can over-testing be problematic.

To measure the value of Function Health, it’s important to weigh the positives and negatives. These will vary from individual to individual, since how one responds and reacts to this information is an important aspect of the value it provides.

At the end of the day, collecting health and fitness data is all about behavior change. When deciding whether or not Function Health is right for you, ask yourself the following questions:

• Do you believe that the data that Function Health provides will help you drive positive change in your life?
• What is preventing you from making those changes now, without Function Health?
• Are you the type of person who might drive yourself crazy by having this type of information?
• Are you mentally prepared to incorporate this data and Action Plan into your life and mindset?

Ultimately, Function Health is just an expensive way to tell yourself: eat healthy and exercise more. Sure, the personalized results are way more granular than that, but when you abstract all those details away, the action items are no different than any other health journey.

For some people, the Apple Watch is a huge motivator. Closing the daily rings, having competitions with other Apple Watch owners, and getting hourly reminders to stand can all drive positive action in a certain type of person. But at the end of the day, each of these Apple Watch functions are all driving towards one thing: a more active lifestyle. If you can motivate yourself to be more active without an Apple Watch, you’ll get the same results.

Likewise, Function Health is a motivator for a certain type of person. Before purchasing, ask yourself: am I the type of person who will be motivated by this?

For me, the answer has proven to be yes. At least, that’s my perspective three months in. The real challenge will be next year, when it comes time to decide if I want to drop another $500 (plus lab fees) on another year or not.

If you, too, feel like you’re the time of person to be motivated by something like this (and you have the money) I say go for it. But know that data is only as useful as you make it, so signing up and doing the testing is only the first step towards positive change.

As I said at the beginning, you’re welcome to use my referral code if you’ve found this useful and want to try Function Health for yourself.

Here’s to a healthier you. Cheers.