Stearic acid optimal range and reference range
Compiled by Alina Radu, founder of Sera, from the published sources below · Last reviewed November 9, 2026
Sera's bands for Stearic acid:
- Optimal 10 – 20 %; sufficient 8 – 25 %; out of range below 8 or above 25 %.
Evidence grade: Published reference interval. A band that primarily reflects a published adult laboratory or population reference interval. It is not necessarily applicable to every assay or laboratory.
All units
| Unit | Optimal | Sufficient | Out of range |
|---|---|---|---|
| % | 10 – 20 | 8 – 25 | below 8 or above 25 |
What the evidence says
No published reference interval or clinical threshold exists for red cell stearic acid in percent; the bands are Sera's own. They are consistent with cohort averages measured by one method across seven countries, 13.7% to 18.2%. The outer edges of 8% and 25% have no source. Largely desaturated to oleic acid in the liver and without palmitic acid's effect on LDL cholesterol, so a high stearic acid is not read the way a high palmitic acid is. Percentages depend on which fatty acids the panel counts, so compare only within one laboratory.
Assay: Results differ meaningfully between platforms and methods. Compare against the interval printed by the issuing laboratory before acting on a borderline value.
Sources
- Red Blood Cell Fatty Acid Patterns from 7 countries: Focus on the Omega-3 Index — Schuchardt JP, Cerrato M, Ceseri M, et al. — Prostaglandins, Leukotrienes and Essential Fatty Acids, 2022 · Peer-reviewed publicationMean red cell levels measured by one laboratory method in 17 cohorts (Italy, Spain, Germany, Canada, United States, Japan, Korea; 167,347 people). Cohort means only: the paper gives no percentiles or reference interval. Stearic acid (C18:0) means: 14.3% to 17.8% outside the US, 13.7% to 18.2% in the US cohorts (Canada 17.8%, Framingham Offspring 18.1%). All lie inside the optimal band of 10 to 20%; no edge is supported.
- Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort — McBurney MI, Tintle NL, Vasan RS, et al. — The American Journal of Clinical Nutrition, 2021 · Peer-reviewed publicationFramingham Offspring, 2,240 adults, 27 red cell fatty acids as percent of total. Only myristic, palmitoleic, behenic acid and the Omega-3 Index predicted all-cause death; stearic acid did not. Supports the statement that there is no outcome-linked threshold.
What Stearic Acid (C18:0, RBC) measures
A long-chain saturated fatty acid found in meat, dairy and cocoa butter.
The saturated fat that behaves differently from the rest: it is largely desaturated to oleic acid in the liver and does not raise LDL cholesterol the way palmitic acid does. A high level is not read the same way.