Remedy Routes
    Cardiovascular
    Strong Evidence

    Endothelial Function

    Healthy blood vessel lining for proper vascular function.

    TL;DR

    Endothelial health is measurable as flow-mediated dilation and predicts cardiovascular events. Dietary nitrate, citrulline and omega-3 improve it in trials, but blood pressure control and smoking cessation dwarf any supplement.

    Why It Matters

    Endothelial dysfunction is the earliest detectable stage of atherosclerosis, appearing years before plaque. Impaired flow-mediated dilation independently predicts future cardiovascular events.

    How to Measure

    Biomarkers

    Flow-mediated dilation
    Blood pressure
    hs-CRP
    ADMA
    Pulse wave velocity

    Optimization Protocol

    Control blood pressure, stop smoking, and train aerobically five days a week. Add dietary nitrate as beetroot juice or citrulline 6 g daily, and omega-3 at 2 g EPA/DHA. Re-assess flow-mediated dilation or blood pressure at 12 weeks.

    Supporting Supplements

    Omega-3 Fatty Acids

    Fatty Acid
    Likely effective
    Strong Evidence
    Effectiveness 4/5

    Solid supporting evidence, especially at higher EPA doses and low baseline omega-3 index.

    L-Citrulline

    Amino Acid
    Strong yes
    Strong Evidence
    Effectiveness 4/5

    One of the better-evidenced supplements for vascular function, with a clear dose-response.

    Vitamin C

    Vitamin
    Mixed evidence
    Moderate Evidence
    Effectiveness 2/5

    Context-dependent. Correct a deficiency, but do not expect vascular benefit if your status is already good.

    Supporting Research

    Frequently Asked Questions

    How is endothelial function measured?
    Flow-mediated dilation of the brachial artery is the research standard, with peripheral arterial tonometry as an alternative. Neither is routinely available outside research or specialist clinics.
    Do dietary nitrates help?
    Yes, fairly consistently. Beetroot juice providing 400-800 mg nitrate improves flow-mediated dilation and modestly lowers blood pressure, with effects appearing within 2-3 hours.
    What about cocoa flavanols?
    Around 500-900 mg/day of cocoa flavanols improves endothelial function in meta-analyses. Most commercial chocolate contains far less than the doses used in trials.
    Does L-citrulline work better than arginine?
    Yes. Citrulline at 6-8 g/day raises plasma arginine more effectively than oral arginine, which is largely broken down in the gut before absorption.
    Is omega-3 useful here?
    EPA and DHA at 2-3 g/day improve endothelial measures modestly in some trials, with more consistent effects on triglycerides than on vascular function.
    What matters more than supplements?
    Stopping smoking, regular aerobic exercise, blood pressure and lipid control, and sleep. Each has a larger and better-documented effect on vascular health.

    Typical Timeframe

    Acute nitrate effects within 3 hours; 8-12 weeks for sustained change

    Research Summary

    Studies15
    Supplements3
    Evidence
    Strong Evidence

    My Notes

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    This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.