What is the sipra membership?

What is your biological age?

Jillian Foglesong Stabile, MD

FAAFP, DABOM · Reviewed June 10, 2026 · Levine phenotypic age method

Chronological age

Albumin

Typical range about 3.5 to 5.0 g/dL.

Creatinine

Typical range about 0.6 to 1.3 mg/dL.

Fasting glucose

Typical fasting range about 70 to 99 mg/dL.

C-reactive protein (hs-CRP)

High-sensitivity CRP, typically under 3 mg/L at lower risk.

Lymphocyte percent

Percent of white cells, typical range about 20 to 40%.

Mean cell volume (MCV)

Typical range about 80 to 100 fL.

Red cell distribution width (RDW)

Typical range about 11.5 to 14.5%.

Alkaline phosphatase

Typical range about 40 to 130 U/L.

White blood cell count

Typical range about 4 to 11 thousand per microliter.

Research-based estimate only, not a diagnosis or a lifespan prediction. Lab values vary day to day. A licensed physician interprets your labs with your history. Individual results vary.

Chapter 01 · The idea

Biological age versus the candles on the cake

Chronological age is how long you have been alive. Biological age is an attempt to estimate how your body is aging, which can run faster or slower than the calendar. This tool uses phenotypic age, a method published by Levine and colleagues in 2018 that combines nine routine blood markers with your chronological age into a single estimate.¹ It was built from large population data and is widely used in aging research.

The markers span several systems: albumin and C-reactive protein relate to inflammation and liver function, creatinine to the kidneys, glucose to metabolism, and the blood-count measures (white cells, lymphocyte percent, mean cell volume, red cell distribution width) to immune and red-cell health. Alkaline phosphatase reflects liver and bone activity. A pattern that looks older or younger than your years nudges the estimate up or down.

Chapter 02 · The fine print

What this number is not

This is a research-based estimate, not a diagnosis and not a prediction of how long you will live. Lab values shift day to day with hydration, illness, recent exercise, and time of day, so a single draw is a snapshot. The method was developed in specific populations and may fit you less well. Most importantly, no calculator replaces a clinician, who interprets your labs alongside your history and decides what, if anything, they mean for your care. Individual results vary.

Use the estimate as a prompt for a conversation, not a verdict. If a marker is outside its usual range, that is a reason to ask a clinician about it, not a reason to worry on your own. Individual results vary.

Every medication on sipra is prescribed by a licensed physician, so your care always starts with a visit. Your sipra membership gives you ongoing access to those physician visits, so you can check in, adjust your plan, and ask questions whenever you need, without paying per visit. It is how we keep high-quality care convenient: one membership, physician access whenever you need it, and support at every step.

Sources

Levine ME, Lu AT, Quach A, et al. "An epigenetic biomarker of aging for lifespan and healthspan." Aging (Albany NY). 2018;10(4):573-591 (phenotypic age). doi.org
Liu Z, Kuo PL, Horvath S, et al. "A new aging measure captures morbidity and mortality risk across diverse subpopulations." PLoS Med. 2018;15(12):e1002718. doi.org

Compounded medications are not FDA-approved and require a patient-specific prescription. Brand names are trademarks of their owners; sipra is not affiliated with them.

General education, not medical advice. Last reviewed June 10, 2026 by Jillian Foglesong Stabile, MD, FAAFP, DABOM. Prices snapshot Levine phenotypic age method. Individual results vary.