People who are on blood pressure medication should monitor their blood pressure levels, or consult their physician before taking arginine. This supplement should be avoided by persons with glaucoma or herpes simplex unless otherwise prescribed by a physician. Do not use if you have had a myocardial infarction or have established coronary artery disease.

If you have diabetes or have ever been diagnosed with cancer or cardiovascular disease, consult your healthcare practitioner before using this product. L-arginine sometimes can reactivate latent herpes virus infections. Those with certain psychoses may experience worsened symptoms if they take L-arginine supplements. Always take antioxidants with L-arginine.

Consult your healthcare professional prior to use if you have or suspect a medical condition or are taking prescription drugs.