Thyroid Health
5 Biomarkers
- Triiodothyronine (T3) Free
- Thyroxine (T4) Free
- Thyroglobulin Antibodies (TgAb)
- Thyroid Peroxidase Antibodies (TPO)
You track what changes. Now understand why.
Function gives you access to 160+ lab tests every year, unlocking the biology behind your daily numbers. See how your daily habits drive your lab results. Withings members get $30 credit toward their first year.
* Regularly $365/year. Offer valid for new members. Credit applies to the first year of membership.
Add a deeper layer to your daily data.
Pair Withings with Function to know what’s happening inside your body. Together, they offer an ongoing view of your metabolic and heart health.
Bring everything together: Your Withings readings sit alongside your 160+ lab results. All your health signals in one place.
Discover patterns: Learn how changes in body composition and blood pressure relate to markers like cholesterol, glucose, and inflammation.
Know what to do next: Use clinician-reviewed insights together with your daily data to make more informed decisions as your health evolves.
Monitor early indicators of 1000s of diseases
Establish your baseline
Understand your results
Track changes over time
AnemiaGoutCeliac diseaseAddison's diseaseInsulin resistanceFatty liver diseasePancreatic cancerOvarian cancerSickle cell diseaseSjögren's syndromeDiabetesRheumatoid arthritisMold toxicity
HypogonadismLupusCoronary artery diseaseHypothyroidismAlzheimer's diseaseHemochromatosisPCOSChronic kidney diseaseHashimoto's thyroiditisProstate cancerLead toxicityGraves' disease
160+ lab tests chosen by top doctors
“The most powerful approach I’ve seen in my career. Uncompromising depth with no shortcuts.”
Cancer Detection & Autoimmunity
34 Biomarkers
- GRAIL Cancer Test
- Rheumatoid Factor (RF)
- Antinuclear Antibodies (ANA) Screen
- Antinuclear Antibodies (ANA) Pattern
Heart Health
15 Biomarkers
- LDL Small
- Lipoprotein (a)
- Apolipoprotein B (Apob)
- High-Sensitivity C-Reactive Protein (hs-CRP)
- Insulin
Male & Female Health
20 Biomarkers
- Anti-Mullerian Hormone (AMH)
- DHEA-Sulfate
- Prostate Specific Antigen (PSA) %, Free
- Prostate Specific Antigen (PSA), Free
- Prostate Specific Antigen (PSA), Total
Metabolic Health
5 Biomarkers
- Glucose
- Hemoglobin A1c (HbA1c)
- Insulin
- Leptin
- Uric Acid
Function like Aimee
The cancer signals doctors missed
Function like Alan
From diabetes diagnosis to action
Function like Geoff
Finding prostate cancer after testing
Function like Catherine
You can't diet or exercise this away
Gold standard for lab testing
Get reliable results from the same labs trusted by half the physicians and hospitals in the U.S.
2,000+ lab test locations across the US
2,000+
2,000+
75M+
75M+
Over 75 million results delivered to Function members
Not your average checkup
Standard checkup
Lab tests annually
160+
~26
No waiting for insurance approval
Biological age testing
Track progress 2x per year
Heart testing beyond cholesterol
Autoimmunity testing
Hormones and fertility testing
Heavy metal and toxin testing
Metabolic and thyroid testing
Scans and add-ons at member pricing
Standard checkup
Lab tests annually
160+
~26
No waiting for insurance approval
Biological age testing
Track progress 2x per year
Heart testing beyond cholesterol
Autoimmunity testing
Hormones and fertility testing
Heavy metal and toxin testing
Metabolic and thyroid testing
Scans and add-ons at member pricing
Frequently asked questions
What is Function?
Function is a membership that gives you access to 160+ lab tests, clinician-reviewed insights, and a personalized health plan so you can understand your results and take action over time.
Why 160+ lab tests?
Anything less could miss critical parts of your health. Typical physicals tend to focus on conventional standards—and what insurance will cover. This broader view can give you key insights to take action sooner.
Which tests are included with a Function membership?
Members get access to 160+ lab tests annually, covering heart, hormones, thyroid, liver, and kidneys, as well as potential heavy metal exposures, nutrient levels, inflammation, potential cancer signals, and more. See all that's included here.
What is the Withings x Function partnership?
Withings and Function have integrated so that your daily device readings and your lab results live in the same place. Withings captures body composition, blood pressure, and more every day. Function connects those signals to the biomarkers that explain them, like Glucose, Insulin, ApoB, and Lp(a).
Do I need both a Function membership and a Withings device to benefit?
Yes. The integration requires an active Function membership and at least one compatible Withings device. Supported metrics sync automatically.
How do I connect my Withings account to Function?
To connect Withings Devices to Function: You'll add your Withings device data to Function through the Connected Apps page in the Function web or mobile experience. You must be a Function member. Authorize the connection with your Withings login. Once linked, data starts syncing automatically.
To connect Function data to Withings: You'll authorize Function from within the Withings app or site. If you're new to Function, you'll be taken through the Function signup and onboarding flow, which includes a share authorization step. If you're an existing Function member, you'll be redirected to log in to Function and authorize the connection. Once linked, your Function results will start syncing to Withings automatically.
How can I apply the Function credit to my membership?
Go to this page and log in to your Withings account, or create one if you don't have one. You'll be prompted to connect your Withings account to Function, then continue to checkout. Your code is automatically applied.