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L-Arginine Ingredient Notes
L-arginine is an amino acid involved in protein and nitric oxide production. Citrulline can be converted to arginine in the body, but remains a different ingredient on a product label.
L-arginine is an amino acid involved in protein and nitric oxide production. Citrulline can be converted to arginine in the body, but remains a different ingredient on a product label.
Community experiences
Selected positive personal experiences from external communities, edited and summarized. These accounts do not establish effectiveness.
A contributor who took arginine tablets before bed wrote that they began waking up without sleeping excessively late. They also described feeling less physically tired and noticing more firmness in their skin. They did not specify the number of tablets, duration of use, or any measurements of sleep or skin changes, so these remain everyday changes perceived by the contributor.
Experience shared by external community contributor A
This page is for general reference only and is not medical advice, diagnosis, treatment, or prescription. Ask a qualified professional if you need medical advice or diagnosis.
What is L-Arginine?
L-arginine is an amino acid involved in protein and nitric oxide production. Citrulline can be converted to arginine in the body, but remains a different ingredient on a product label.
On Supplecipe, you can search iHerb products that mention L-Arginine and compare single-ingredient products against broader supplement blends.
Evidence and limitations
Its role in nitric oxide production does not guarantee improved exercise performance or strength from supplements. NIH ODS describes limited trials with conflicting findings.
NIH ODS: Exercise and Athletic Performance · Mayo Clinic: L-arginine · Mayo Clinic: L-arginine and blood pressure
Forms and other names
L-arginine and arginine refer to the amino acid. Free-form arginine, arginine HCl and arginine alpha-ketoglutarate (AAKG) have different ingredient forms; citrulline and ornithine are separate ingredients.
Related ingredients
Related reading, not a recommendation to combine supplements.
Side effects and cautions
Nausea, abdominal pain and diarrhea may occur. Blood-pressure medicines, nitrates or sildenafil can increase the risk of low blood pressure when combined with arginine. Do not use after a recent heart attack. Discuss kidney disease, herpes history or planned surgery with a healthcare professional.
NIH ODS: Exercise and Athletic Performance · Mayo Clinic: L-arginine · Mayo Clinic: L-arginine and blood pressure
How to compare iHerb products
- Distinguish the whole HCl or AAKG ingredient weight from the amount of arginine supplied. Do not count citrulline or an entire pre-workout blend as arginine; check other ingredients such as caffeine.
- Look for form, serving size, extra ingredients, allergens, and whether the product is a single ingredient or a blend.
- Compare brand, price per serving, ingredient form, and single-ingredient versus complex products.
- Use the search button below to compare iHerb products that mention this ingredient.
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