Test smarter. Act sooner. Live longer.

Function gives you access to lab tests that standard care often skips—and the tools to act on your results. Know more and do more, before symptoms appear.

Thyroid

Autoimmune thyroid diseases do not always show up on standard tests. Most thyroid testing stops at thyroid-stimulating hormone (TSH). But even when TSH looks normal, other markers can point to autoimmune diseases like Hashimoto's or Graves'.

Overlooked biomarkers you get with Function:

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15%

15% of female Function members

show elevated TPO and TgAb, even with normal TSH—clear signs of early autoimmune thyroid disease.

Member testimonial

Taking responsibility for metabolic health

I take full responsibility for my health. That means understanding the details of my metabolic systems, not to the level of a Dr. or specialist, but well enough to be able to have a conversation with a Dr. and understand what they are explaining to me. Function Health is an incredible tool to help me do this.

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Trusted by thousands

Millions of tests. Just the beginning.

We built Function to open up access to the kind of health knowledge most people never had.

Our members are now driving a new standard—taking control of their health, before symptoms start.

75 million +

Tests completed by Function members

Setting a higher standard

Illustration representing Function testing twice a year.

Testing 2x a year

Your health can change fast. We keep up.

While standard healthcare only tests once a year, Function membership includes an Annual Test and a Mid-Year test 3-6 months later—to help you catch changes, track progress, and make smarter decisions before symptoms start.

Illustration representing Function lab tests.

100+ lab tests

We test what others miss.

Function membership includes 100+ biomarkers in your Annual Test and 60+ in your Mid-Year Test. This set of tests was rigorously selected by clinicians to flag risks that your average physical doesn’t.

Illustration representing clinical-grade lab testing.

Clinical-grade labs

Test with confidence.

All lab visits take place with trained phlebotomists, for cleaner samples and more reliable results. Your health information is protected with HIPAA-aligned systems and SOC 2 Type II compliance. That’s the Function standard.

Mark Hyman, M.D.

Former Cleveland Clinic physician. Co-founder and chief medical officer of Function.

JoAnn E. Manson, M.D., MPH, DrPH

Chief of Preventive Medicine at Brigham & Women's Hospital. Professor at Harvard.

Andrew Huberman, PhD

Professor of Neurobiology at Stanford School of Medicine.

Toby Cosgrove, M.D.

Former CEO of Cleveland Clinic. Top heart surgeon.

Daniel Sodickson, M.D., PhD

Former chief of innovation in radiology at NYU Langone. Pioneer of AI-driven MRI. Chief medical scientist at Function.

Azra Raza, M.D.

Top medical oncologist. Professor at Columbia University.

Eddie Chang, M.D.

Professor and chair of Neurological Surgery at UCSF.

Luis A. Diaz, M.D.

Head of the Division of Solid Tumor Oncology at Memorial Sloan Kettering Cancer Center.

Yves Michel Duroseau, M.D.

Chair of the Department of Emergency Medicine at Lenox Hill Hospital.

Jordan Shlain, M.D.

Primary care physician. Founder and chairman of Private Medical.