L-arginine is possibly effective for…
Chest pain (angina)
Taking L-arginine seems to decrease symptoms and improve exercise tolerance and quality of life in people with angina. However, L-arginine does not seem to improve the disease itself.
Erectile dysfunction (ED)
Taking 5 grams of L-arginine by mouth daily seems to improve sexual function in men with ED. Taking lower doses might not be effective.
High blood pressure
There is early evidence that taking L-arginine by mouth can reduce blood pressure in healthy people, people with high blood pressure, and people with slightly high blood pressure with or without diabetes.
Inflammation of the digestive tract in premature infants
Adding L-arginine to formula seems to prevent inflammation of the digestive tract in premature infants.
Nitrate tolerance
Taking 700 mg of L-arginine four times daily seems to prevent nitrate tolerance in people taking nitroglycerin for chest pain (angina pectoris).
Leg pain associated with poor blood flow (peripheral arterial disease)
Research suggests that taking L-arginine by mouth or intravenously (by IV) for up to 8 weeks increases blood flow in people with peripheral arterial disease.
Improving recovery after surgery
Taking L-arginine with ribonucleic acid (RNA) and eicosapentaenoic acid (EPA) before surgery or afterwards seems to help reduce the recovery time, reduce the number of infections, and improve wound healing after surgery.
High blood pressure during pregnancy (pre-eclampsia)
Although there are inconsistent results about the effects of L-arginine on pre-eclampsia, most research suggests that it can reduce blood pressure in women with this condition.
Source: medlineplus.gov