I Paid $365 for a Direct-to-Consumer Blood Panel. It Uncovered Health Issues I Never Expected
On TikTok. During television commercials. At dinner with your own family members. These days, unsolicited health advice is, well, everywhere. And while it often comes from the right place—that college friend suggesting a new protein powder really is just trying to help—that doesn't mean the advice is right for you.
We all have different genes, lifestyles, conditions, needs, and goals that comprise our overall health. So why are we all following the same health advice?
Enter: Function , the membership platform trying to personalize health advice for your body. Function gives you insight into 160+ biomarkers across two tests a year, offering a detailed view into organ function, immune regulation, hormones, stress levels, and other key areas.
But is it worth an annual fee of $365 for two tests a year? I tried Function myself to find out, and I got so much more than I bargained for.
Related: The 5 Heart Tests Men Over 50 Should Never, Ever Skip, According to Cardiologists
How Direct-to-Consumer Blood Tests Work
Step 1: Get Your Biomarker Blood Test
It takes just a few minutes to make an account with Function. After that, I made an appointment at my local Quest Diagnostics to get my blood drawn and start the process.
I decided to add on a food sensitivity test, because I've always wondered if certain foods could be causing my GI issues, but there's no shortage of extras depending on what you need. Other add-ons range from advanced cancer screening to cognitive decline tests. This is the first point where Function differs from the average blood test. I didn't see a doctor to order my labs—I ordered them myself and decided which ones I wanted.
At Quest, the phlebotomist told me she sees Function patients multiple times a day, every day. She confirmed that more people are being drawn to direct-to-consumer blood test platforms like Function because they provide a much more comprehensive panel, without an initial doctor's visit, at a relatively low cost.
But how much money does a platform like Function actually save?
A typical complete blood test (CBC) costs $29 —that tells you things like your red blood cell, white blood cell, and platelet levels. Testing cortisol costs $79 , and a comprehensive testosterone panel can cost $159 .
Consider that each marker adds an additional cost—and that you'll likely have to pay for both the doctor's visit and the lab tests themselves—and it isn't surprising people are taking things into their own hands. Plus, you may be able to pay for Function with your HSA or FSA.
"With our healthcare system and how deductibles are set up and insurance plans, people don't want to get a surprise bill," says Tiffany Lester, MD, a medical director at Function Health. "Function really makes the cost super transparent. It's much less than what you would get if your doctor ordered these same tests."
Step 2: Receive Your Results
Results take just a few weeks to begin appearing in Function's online dashboard. Those first set of tests in your Function dashboard provide a baseline. By testing key biomarkers every six months, it becomes easier to detect subtle changes before symptoms occur—providing better outcomes over time.
"Getting data and seeing it in black and white—even if maybe you're having symptoms, but have brushed it off—is really impactful to catch chronic conditions," Dr. Lester says. "There are multiple levels of research that show the earlier you catch a condition, the easier it is to treat, and the better the outcome."
She points to testosterone as an example, because the range of healthy testosterone can vary greatly from person to person. Instead of just looking at testosterone once, Function's bi-annual testing model provides insights into changes over time, even if they're small, which could suggest the need for further investigation.
In the same vein, once you have a baseline, Function can help you understand how taking supplements can help or improve certain health challenges. The company's recent acquisition of SuppCo, a supplement platform, helps people find supplement brands they can trust, evaluate quality, and build a stack of supplements — all while tracking the health impact of taking those products.
Related: Blood Tests May Reveal a Hidden Form of Depression, Psychiatrist Says
Step 3: Hone In on Metrics
Function will tell you which biomarkers are out of range, but as with any blood test, it's not always indicative of a long-term issue.
For example, I drank a lot of water leading up to my early morning test so that my veins would be primed for blood draws, and I had been fasting since dinner the night before. This skewed my electrolytes number to be slightly below average.
Another measurement that caught my eye? Biological age. I'm 34, so I'd be lying if I said I didn't feel proud when I saw my biological age in Function was just 21 years old. Function determines biological age through a calculation of aging-related biomarkers—like inflammation and kidney function.
Sadly, touting your biological age isn't going to get you anywhere in life; however, it's a number that can encourage you to maintain healthy habits (and pick up new ones).
"I think it can be an indicator and gives people motivation to continue to be better," Dr. Lester says. "We all know that we should exercise and eat healthy and get eight hours of sleep, but doing it, we need motivation, and numbers really help to do that." 

Step 4: Take Action
I had a number of out-of-range metrics in my results—some of which I knew about, like high LDL-cholesterol, to which I'm genetically predisposed.
Other ones I didn't expect—like low omega-3s, low vitamin D, and low ferritin, which reflects the body's stored iron levels.
All of these, combined with above-average reactions on my food sensitivity test add-on, point to something seriously up with my ability to absorb nutrients, meaning a deeper gut condition could be at play. It also explains some chronic issues I've been facing, like fatigue, sleep disturbances, and GI issues.
Instead of feeling overwhelmed, however, Function's accessible explainers helped me understand what the metric is, why it's out of range, and why it matters. Now, I don't have to start with that dreaded initial doctor's appointment, in which you tell them you're tired and can't sleep, issues so broad they can lead you in a million different (and wrong) directions.
Instead, I can tell my doctor my symptoms, provide the metrics that back up these experiences, and ask how we can work together to reach a healthier, better me. In that way, Function puts a little bit of control back into the patient's hands.
"The doctor has been the gatekeeper. You go to the appointment, you're having symptoms, and they decide what testing you get," Dr. Lester says. "Now, you're able to get these tests, and then you're going to the doctor. You have the information, so you're not starting from zero when you walk in."
In other words, Function helps patients feel more like a team with their doctor, working to solve a problem together.
"I think the best therapeutic relationships or partnerships are not a dictatorship," Dr. Lester says. "You know your body the best."
This story was originally published by Men's Journal on Sep 2, 2026, where it first appeared in the Health section. Add Men's Journal as a Preferred Source by clicking here.
