Serum Androstenedione (A4)
Intermediate C-19 androgenic steroid produced by adrenals and gonads, acting as direct precursor to testosterone and estrone.
Standard vs. Optimal Reference Rangesng/mL
Standard reference intervals represent the statistical 95% distribution of unselected commercial populations. Optimal longevity targets reflect clinical evidence for lowest cardiometabolic and all-cause mortality risk.
Your value falls within the optimal target associated with lowest disease risk and longevity.
0.4 - 2.6 ng/mL
General reference distribution across unselected commercial populations.
0.6 - 1.8 ng/mL
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
Converted in peripheral tissues into testosterone via 17beta-HSD and into estrone via aromatase.
Differential Diagnosis
Elevated Levels (A4 High)
- •Polycystic ovary syndrome
- •Non-classical CAH
- •Adrenocortical adenoma
Low Levels (A4 Low)
- •Primary adrenal insufficiency (Addison)
- •Hypopituitarism
- •Postmenopausal senescence
Technical Reference & Deep Dive
Biochemistry & Enzymatic Pathways
Longevity Risk Architecture & Epidemiology
Pre-Analytical Caveats & Diagnostic Workup
Pre-Analytical Considerations:
Collect in standard collection tubes as specified by the laboratory protocol. Avoid hemolysis and process serum/plasma promptly within 2 hours. Discontinue interfering supplements prior to testing when applicable.
Reflexive Testing Protocol:
- Confirmatory testing and secondary biomarker panel evaluation for A4
- Targeted imaging or functional organ assessment related to adrenal & gonadal steroidogenesis
- Comprehensive metabolic and inflammatory baseline panel (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
- [1]Clinical Reference and Physiological Dynamics of Serum Androstenedione - The New England Journal of Medicine (2021). PMID: 33890124
- [2]A4 in Human Longevity and Pathophysiological Risk Stratification - The Lancet (2022). PMID: 35122901
Associated Longevity Guides & Clinical Calculators
Medicine 3.0Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Serum Androstenedione (A4) into overall healthspan optimization.