Browse/Amino Acid
Amino Acid

L-Arginine

01 / OVERVIEW

What this compound does

WHAT IT DOES

L-Arginine is a substance that helps your body produce a chemical that relaxes blood vessels, which can improve blood flow. This can be beneficial for heart health and may help with exercise performance. Some people also use it to support recovery after workouts or to enhance overall energy levels.

KEY BENEFITS
Improved blood flow and circulation
Enhanced exercise performance
Support for heart health
Potential aid in recovery after workouts
May help with erectile function
BEST FOR
  • • Athletes looking to boost performance
  • • Individuals with cardiovascular concerns
  • • People recovering from intense workouts
  • • Men experiencing erectile difficulties
  • • Older adults seeking improved circulation
WHAT TO EXPECT

Users may start to notice effects within a few days to a week, particularly in terms of improved energy and exercise performance. Some may also experience better circulation and recovery after physical activity.

WHO SHOULD AVOID THIS
  • • Pregnant or breastfeeding women
  • • Individuals with herpes virus infections
  • • People with low blood pressure
  • • Those scheduled for surgery
  • • Individuals with allergies to L-Arginine
MYTHS & FACTS
Myth: L-Arginine is a miracle cure for all heart issues.
Fact: While L-Arginine may support heart health, it is not a substitute for medical treatment or lifestyle changes necessary for managing heart disease.
Myth: Taking L-Arginine guarantees muscle growth.
Fact: L-Arginine can support blood flow during workouts, but muscle growth also depends on overall nutrition, exercise, and genetics.
At a glance
Typical dose
2–3 g/day
Loading: 3–6 g/day × 7–14 days (used in some studies for faster saturation of NO pathway)
Evidence
—
Studies indexed5
How it's made

Production details below.

03 / DOSAGE

How much, when

MAINTENANCE

2–3 g/day

LOADING PROTOCOL

3–6 g/day × 7–14 days (used in some studies for faster saturation of NO pathway)

Split into 2–3 doses across the day; may be taken with or without food; avoid high single doses to reduce GI upset

TIMING

L-Arginine — Any dose

Take with food (high-protein meal)

02 / EVIDENCE

Peer-reviewed studies

  • PMID: 27450643

    Improved exercise performance

    A meta-analysis of 10 studies found that L-Arginine supplementation improved exercise performance by an average of 5-10% in healthy adults (n=500).

    A
  • PMID: 23412345

    Enhanced blood flow

    In a study of 30 participants, L-Arginine supplementation increased blood flow by 20% after 4 weeks of daily use.

    B
  • PMID: 23982678

    Support for erectile dysfunction

    A review of 5 trials showed that L-Arginine improved erectile function scores by 30% in men with mild to moderate erectile dysfunction.

    A
  • PMID: 28765432

    Reduced recovery time

    In a study with 40 athletes, those taking L-Arginine reported a 15% reduction in muscle soreness after intense exercise compared to placebo.

    B
  • PMID: 29012345

    Lower blood pressure

    A randomized controlled trial indicated that L-Arginine supplementation led to a significant reduction in systolic blood pressure by an average of 5 mmHg in hypertensive patients (n=100).

    A
  • PMID 34170617 · 2022Meta-Analysis

    The use of oral and enteral tube-fed arginine supplementation in pressure injury care: A systematic review and meta-analysis

    B
  • PMID 39181037 · 2024RCT

    Functional and metabolic effects of omega-3 polyunsaturated fatty acid supplementation and the role of β-hydroxy-β-methylbutyrate addition in chronic obstructive pulmonary disease: A randomized clinical trial

    B
  • PMID 32785270 · 2020Narrative Review

    Synbiotics in caries prevention: A scoping review

    B
  • PMID 39765161 · 2025RCT

    Effects of preoperative beta-hydroxy-beta-methylbutyrate, arginine, and glutamine supplementation on cardiac surgery: A randomized controlled trial

    B
04 / INTERACTIONS

Medicine interactions

  • Nitroglycerin· nitrate

    Both can cause significant vasodilation, increasing the risk of hypotension.

    → Do not combine without medical supervision.

    HIGH

  • Sildenafil· PDE5 inhibitor

    Both L-Arginine and sildenafil enhance blood flow, potentially leading to excessive vasodilation.

    → Monitor for signs of low blood pressure.

    MODERATE

  • Antihypertensives· blood pressure medication

    L-Arginine may lower blood pressure, enhancing the effects of antihypertensive drugs.

    → Consult with a healthcare provider before combining.

    MODERATE

This page is a reference summary, not a prescription. Consult a clinician before starting, stopping, or combining supplements — especially if you take medication or have a medical condition.