Amino acids
L-arginine
Also called: arginine
An amino acid the body uses to make nitric oxide, which widens blood vessels.
- Why people take it
- Blood flow, blood pressure, erections, exercise.
- What the evidence says
- Small blood pressure drops; mixed results for exercise and erections.
- How it is usually taken
- Usually 3 to 6 g a day in divided doses.
- Be careful
- Can lower blood pressure too much with medicines. Not for people who recently had a heart attack, or with herpes.
- Medicines it can interact with
- Adds to blood-pressure lowering with BP medicines, nitrates and sildenafil or tadalafil. Avoid after a heart attack.
Other amino acids
Common questions
What is L-arginine?
An amino acid the body uses to make nitric oxide, which widens blood vessels.
Why do people take L-arginine?
Blood flow, blood pressure, erections, exercise.
Does L-arginine work?
Small blood pressure drops; mixed results for exercise and erections.
How much L-arginine do people take?
Usually 3 to 6 g a day in divided doses.
Is L-arginine safe?
Can lower blood pressure too much with medicines. Not for people who recently had a heart attack, or with herpes.
Does L-arginine interact with medicines?
Adds to blood-pressure lowering with BP medicines, nitrates and sildenafil or tadalafil. Avoid after a heart attack.
Sources and further reading
Last reviewed 31 October 2026. Written by Satya Babu.
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