L-Arginine

Effects and Benefits

Core Identification

Common Names:
- L-Arginine
- Arginine
- L-Arg

Latin Name: Not applicable (amino acid compound)

Category: Amino Acid

Uses

Traditional Uses

• Cardiovascular support - Used traditionally to support heart and circulatory health
• Wound healing - Applied in recovery from surgery, injuries, and burns
• Male virility and fertility - Traditional use for enhancing male sexual function and sperm health

Modern Uses

• Cardiovascular Support - Decreases inflammation, increases vasodilation, may help with coronary artery disease, angina, and atherosclerosis; reduces fluid buildup after congestive heart failure | Research quality: Moderate
• Key findings: Angina patients taking 2g three times daily improved exercise tolerance before chest pain onset; mechanism involves nitric oxide-mediated blood vessel relaxation

• Source citations: Brewer - TDT Encyclopedia of Vitamins; Moline - The Doctors Book of Natural Health Remedies

• Blood Pressure Support - May reduce blood pressure through vasodilation | Research quality: Moderate

• Key findings: More than 10 randomized trials showed L-arginine can reduce systolic blood pressure by an average of 5-6 mm Hg and diastolic by 2-3 mm Hg; however, some sources note the evidence does not consistently support this use

• Source citations: Moyad - The Supplement Handbook; Moline - The Doctors Book of Natural Health Remedies

• Wound Healing - Improves wound healing by increasing new blood vessel growth around wounds | Research quality: Moderate

• Key findings: Supplemental arginine brings vital oxygen and nitrogen to healing tissue; involved in collagen synthesis; beneficial during recovery from surgery, injuries, and burns

• Source citations: Moline - The Doctors Book of Natural Health Remedies; Brewer - TDT Encyclopedia of Vitamins

• Sexual Health (Combined Formulas) - Improves erectile function and female sexual health when combined with other ingredients | Research quality: Moderate

• Key findings: L-arginine aspartate (2,800mg) combined with Pycnogenol (80mg) improved erectile function in a 6-month clinical trial; ArginMax (arginine + ginseng) improved arousal, desire, and orgasm in premenopausal women; by itself, arginine showed modest results (6 of 15 men improved in one small trial)

• Source citations: Moyad - The Supplement Handbook; Brewer - TDT Encyclopedia of Vitamins

• Sperm Health and Male Fertility - Supports sperm quality and motility | Research quality: Preliminary

• Key findings: Seminal fluid contains as much as 80% arginine; supplementation with 4-8g daily may improve sperm count in men with unexplained low sperm count

• Source citations: Brewer - TDT Encyclopedia of Vitamins

• Blood Sugar Support - May support glucose metabolism | Research quality: Preliminary

• Key findings: Stimulates insulin production in the pancreas and has been shown to improve blood glucose control in people with type 2 diabetes

• Source citations: Brewer - TDT Encyclopedia of Vitamins

• Immune Function - Supports immune response | Research quality: Preliminary

• Key findings: Boosts production and activity of T-lymphocytes; may improve immunity against certain infectious diseases

• Source citations: Brewer - TDT Encyclopedia of Vitamins

• Exercise Endurance - May improve exercise performance in untrained individuals | Research quality: Weak

• Key findings: Some studies suggest improvement in exercise endurance, but primarily in untrained athletes
• Source citations: Moline - The Doctors Book of Natural Health Remedies

Active Compounds

Primary Active Ingredients:
- L-Arginine - The amino acid itself; serves as the substrate for nitric oxide synthase enzyme
- Nitric Oxide (NO) - The active metabolite produced from arginine; causes vasodilation by relaxing smooth muscle in blood vessel walls
- Creatine precursor - Arginine is one of three amino acids used to synthesize creatine in the body
- Growth hormone stimulant - Arginine stimulates release of growth hormone from the pituitary gland

Dosage Information

Standard Dosage:
- Form: Capsule, powder, or tablet
- Amount: 500 mg to 2,000 mg per day
- Frequency: Once to three times daily, preferably on an empty stomach

Therapeutic Dosage:
- Form: Powder or high-dose capsules
- Amount: 4,000 to 8,000 mg per day (divided doses)
- Purpose: Blood pressure support, cardiovascular health
- Duration: Effects typically require 2-6 weeks to reach full benefit

Sexual Health Dosage:
- L-Arginine aspartate: 2,800 mg combined with Pycnogenol 80 mg daily (Prelox formula)
- Standalone: Some men require 6,000 mg to notice effects
- Timing: Take 1 hour before sexual activity for acute use

Wound Healing/Recovery Dosage:
- Form: Capsule or powder
- Amount: 6,000 to 12,000 mg per day (in clinical studies for coronary heart disease)
- Duration: Throughout recovery period

Maximum Safe Dosage:
- Daily maximum: 20,000 mg (20 grams) is generally not recommended
- Warning threshold: High doses (6g+) commonly cause diarrhea; very high doses may cause skin thickening with long-term use

Bioavailability Notes:
- The liver and intestines remove large quantities of ingested L-arginine, reducing conversion to nitric oxide
- L-Citrulline is often preferred as it bypasses first-pass metabolism and converts to arginine more efficiently in the kidneys
- Chelated forms (arginine chelated with manganese) are more easily absorbed
- Take on an empty stomach for best absorption; nighttime dosing may optimize growth hormone release

How to Take It

Timing:
- Best taken on an empty stomach
- Nighttime dosing may be optimal since growth hormone is mainly released during sleep
- For sexual health purposes, take 1 hour before activity
- Can be taken with or without food for general cardiovascular support
- Effects typically require 2-6 weeks of consistent use to reach full benefit

Synergies - What It Works Well With

Complementary Supplements:
1. Pycnogenol (Pine Bark Extract) - The combination (2,800mg arginine + 80mg Pycnogenol) has strong clinical evidence for erectile function and raised testosterone in trials | Enhanced nitric oxide production and antioxidant support
2. L-Citrulline - Citrulline converts to arginine in the kidneys with better bioavailability; can be used together or citrulline alone at half the dose | More efficient nitric oxide pathway
3. L-Lysine - Essential balance for those prone to herpes infections; lysine suppresses viral replication that arginine may promote | Prevents potential cold sore activation
4. Panax Ginseng - ArginMax formula combines these for female sexual health; benefits observed in premenopausal and perimenopausal women | Enhanced sexual function and arousal
5. Vitamin C - Supports nitric oxide function and antioxidant protection | Enhanced vascular health
6. CoQ10 - Both support cardiovascular function and blood pressure | Complementary heart health support

Avoidance - What NOT to Combine With

Supplement Interactions:
1. High-arginine foods during herpes outbreaks - Nuts, seeds, chocolate, and oatmeal are high in arginine and may promote viral replication | May trigger or worsen cold sores

Drug Interactions:
1. PDE5 Inhibitors (Viagra, Cialis, Levitra) - Both increase nitric oxide and lower blood pressure | Potential for dangerous blood pressure drop | Severity: Severe - Do not combine without physician approval
2. Blood Pressure Medications - Additive blood pressure lowering effects | May cause hypotension | Severity: Moderate
3. Blood Thinners (Warfarin, Aspirin) - Arginine may increase bleeding risk | Monitor for signs of excessive bleeding | Severity: Moderate
4. Nitroglycerin and Nitrates - Both work via nitric oxide pathway | May cause excessive vasodilation and hypotension | Severity: Severe
5. Diabetes Medications - May enhance blood sugar lowering effects | Monitor blood glucose closely | Severity: Moderate

Food Interactions:
- High-lysine foods (dairy, legumes) may reduce arginine effectiveness if taken simultaneously
- Chocolate and nuts are high in arginine but may not be suitable during herpes outbreaks

Safety Information

Contraindications:
- History of Heart Attack (Myocardial Infarction) - CRITICAL: Evidence suggests arginine may be harmful for those who have had a heart attack; DO NOT take if you have experienced one
- History of Peripheral Artery Disease - Safety concerns when combined with L-arginine, particularly with Pycnogenol combinations
- Active Herpes Simplex Infection - Unless balanced with equal amounts of lysine; arginine may support viral replication
- Scheduled Surgery - Discontinue at least 2 weeks before surgery due to bleeding risk and blood pressure effects
- Low Blood Pressure (Hypotension) - May further lower blood pressure
- Guanidinoacetate Methyltransferase Deficiency - Rare genetic condition affected by arginine metabolism

Side Effects:
- Common: Diarrhea (especially at doses above 6g), abdominal pain, bloating, gastrointestinal discomfort
- Less Common: Allergic reactions, worsening of existing allergies, nausea
- Rare: Reversible skin thickening and coarsening with long-term high-dose use
- Blood pressure lowering may cause dizziness or lightheadedness

Long-Term Use:
- Generally considered safe at moderate doses (up to 3g daily) for extended periods
- Very high doses (10g+) long-term may cause skin changes
- Those prone to herpes should balance with lysine supplementation
- Monitor blood pressure if using long-term

Special Precautions:
- Surgery: Discontinue 2 weeks before scheduled surgery
- Pregnancy/Breastfeeding: Insufficient safety data; consult healthcare provider
- Children: Not recommended without medical supervision
- Kidney Disease: Use with caution; kidneys involved in arginine-citrulline conversion
- Asthma: Some case reports of worsening symptoms

Primary Uses At-a-Glance

Primary:
- Cardiovascular and circulation support
- Sexual health and erectile function (especially in combination formulas)
- Blood pressure support
- Wound healing and surgical recovery

Secondary:
- Male fertility and sperm health
- Blood sugar support
- Immune function
- Athletic performance (limited evidence)
- Growth hormone stimulation

Sources

Local Library:
- Moyad, Mark - The Supplement Handbook
- Moline, Peg - The Doctors Book of Natural Health Remedies
- Brewer, Sarah - TDT Encyclopedia of Vitamins
- Curtis, Susan - Neal's Yard Remedies
- Gaby, Alan R. - A-Z Guide to Drug-Herb-Vitamin Interactions
- Balch, Phyllis - Prescription for Herbal Healing
- Hale, Meredith - Home Remedies
- White, Linda B. - 500 Time-Tested Home Remedies

General Knowledge:
- Clinical trials on L-arginine and Pycnogenol (Prelox studies)
- ArginMax clinical research published in Journal of Sex & Marital Therapy
- American Journal of Hypertension blood pressure meta-analyses