1.15BiomarkersReference Guide2,800 words - 14 min read
The Complete Lab Reference Guide: Normal Ranges vs Longevity Optimal Targets for 50+ Biomarkers
A comprehensive, print-and-keep reference guide comparing standard lab reference ranges with longevity-optimized targets for every major biomarker covered in the IQ Healthspan library — organized by category for easy clinical use.
Derek Giordano
Founder & Editor, IQ Healthspan
Mar 8, 2027
Published
Apr 8, 2026
Updated
Key Takeaways
- The distinction between standard reference ranges and longevity-optimal targets is the most practically important concept in preventive medicine. Standard ranges are established from population distributions and represent statistical normality in a population with 40 percent metabolic syndrome prevalence — not biological optimality.
- The highest-value targets to optimize beyond standard normal ranges are: ApoB (target below 70 vs standard below 100 mg/dL), fasting insulin (target below 7 vs standard below 25 uIU/mL), 25-OH vitamin D (target 40-60 vs standard 20-50 ng/mL), hsCRP (target below 1.0 vs standard below 3.0 mg/L), and TSH (target 1.0-2.5 vs standard 0.4-4.0 mIU/L).
- Biomarkers should be interpreted in the context of the whole clinical picture, not in isolation. An elevated hsCRP in the context of a recent respiratory infection is normal; persistent elevation across multiple measurements warrants investigation.
- Serial tracking of biomarker trends is more valuable than any single measurement. A fasting insulin rising from 5 to 9 uIU/mL over 3 years, even while remaining within normal range, signals developing insulin resistance that warrants intervention.
- This reference guide is intended as a companion to article 1.9 (The Complete Longevity Lab Testing Guide). That article covers testing strategy and frequency; this article provides the numerical targets.
This reference guide presents longevity-optimized targets for the biomarkers most relevant to aging medicine, alongside standard lab reference ranges. It is intended as a practical clinical companion to the testing strategy in article 1.9.1
Cardiovascular and Lipid Biomarkers
| Biomarker | Standard Lab Range | Longevity Optimal Target |
|---|---|---|
| Total cholesterol | Below 200 mg/dL | 150-180 mg/dL (without statin) |
| LDL cholesterol | Below 100 mg/dL | Below 70 mg/dL preferred |
| ApoB | Below 100 mg/dL | Below 70 mg/dL |
| HDL cholesterol (men) | Above 40 mg/dL | Above 50 mg/dL preferred |
| Triglycerides | Below 150 mg/dL | Below 80 mg/dL optimal |
| Lp(a) | Below 50 mg/dL | Below 30 mg/dL ideal; test once |
| hsCRP | Below 3.0 mg/L | Below 1.0 mg/L optimal |
| Homocysteine | Below 15 umol/L | Below 9 umol/L |
Metabolic Biomarkers
| Biomarker | Standard Lab Range | Longevity Optimal Target |
|---|---|---|
| Fasting glucose | 70-99 mg/dL | 70-85 mg/dL |
| HbA1c | Below 5.7% | Below 5.3% optimal |
| Fasting insulin | Below 25 uIU/mL | Below 7 uIU/mL |
| HOMA-IR | Below 2.5 | Below 1.0 optimal |
| Uric acid (men) | 3.4-7.0 mg/dL | Below 5.5 mg/dL |
| Uric acid (women) | 2.4-6.0 mg/dL | Below 5.0 mg/dL |
| Ferritin (men) | 12-300 ng/mL | 50-150 ng/mL |
| Ferritin (women, post-M) | 12-150 ng/mL | 30-100 ng/mL |
Nutritional Biomarkers
| Biomarker | Standard Lab Range | Longevity Optimal Target |
|---|---|---|
| 25-OH Vitamin D | 20-50 ng/mL | 40-60 ng/mL |
| Omega-3 index | No standard range | Above 8% |
| Vitamin B12 | 200-900 pg/mL | Above 400 pg/mL; ideally 500-900 |
| RBC Magnesium | 4.2-6.8 mg/dL | Upper half of range (above 5.5) |
| Zinc (plasma) | 60-120 ug/dL | Upper half of range (above 90) |
Hormonal Biomarkers
| Biomarker | Standard Lab Range | Longevity Optimal Target |
|---|---|---|
| TSH | 0.4-4.0 mIU/L | 1.0-2.5 mIU/L |
| Total testosterone (men) | 300-1000 ng/dL | 500-900 ng/dL (age-adjusted) |
| Free testosterone (men) | 9-30 pg/mL | 15-25 pg/mL preferred |
| IGF-1 | Age-specific | Mid-range for age; avoid both extremes |
| DHEA-S (men) | 80-560 ug/dL | Upper third of age-appropriate range |
References
Derek Giordano
Founder & Editor, IQ Healthspan
Derek Giordano is the founder and editor of IQ Healthspan. Every article is independently researched and sourced to peer-reviewed scientific literature with numbered citations readers can verify. Derek has spent over a decade synthesizing longevity research, translating complex clinical and preclinical findings into accessible, evidence-based guidance. IQ Healthspan maintains no supplement brand partnerships, affiliate relationships, or financial conflicts of interest.