In brief: L-arginine is an amino acid and precursor of nitric oxide, so it can affect blood-vessel tone and circulation. That makes it biologically interesting, but not a universal heart, muscle or potency treatment.
What do studies show in erectile dysfunction?
| Topic | Interpretation |
|---|---|
| Mild to moderate ED | Small positive effects in meta-analysis |
| Libido | No clear effect |
| Testosterone | Not a reliable booster |
| Muscle gain | Does not replace training and protein |
A meta-analysis of 10 randomised trials involving 540 men found improvements in mild to moderate ED with 1,500–5,000 mg arginine per day compared with placebo or no treatment.[1]
Side effects and interactions
Possible effects include gastrointestinal symptoms and lower blood pressure. Caution is appropriate with antihypertensive medicines, nitrates and PDE-5 inhibitors.
FAQ
Can L-arginine help erectile problems?
Small benefits are possible in mild to moderate ED.
Does it increase libido?
Not reliably.
Does it raise testosterone?
Not reliably.
Can it be combined with sildenafil?
Only with professional guidance because both can affect blood pressure.
Conclusion
L-arginine may be useful for selected men with mild to moderate ED. Broader potency, muscle or heart claims exceed the evidence.
