Reasons to Not Take L-Arginine

L-arginine is a semi-essential amino acid produced in the body that is necessary for manufacturing protein in the body. Occasionally, the body does not make enough and supplementation may be needed. L-arginine supplements may be used to treat various health conditions, including chest pain, heart disease, atherosclerosis, erectile dysfunction, vascular headaches and high blood pressure. However, due to the adverse side effects and reactions this supplement may cause, consult a doctor before use.

L-arginine capsules sit next to a big jar of protein powder on a white counter. (Image: CobraCZ/iStock/Getty Images)

Major Side Effects

L-arginine should be used with caution. Side effects may include nausea, gastrointestinal discomfort, bloating, diarrhea, hives, lower back pain, leg restlessness, numbness, rash, endocrine changes, increased inflammatory response, increased blood urea nitrogen, severe tissue necrosis and venous irritation. It may also cause hypotension and hyperkalemia, or increased levels of potassium in the blood. For those who suffer from heart disease, using L-arginine may cause an increased white blood cell count, lack of energy and strength, vertigo, increased blood pressure and post-heart-attack deaths.

Causes Allergies

Using L-arginine may cause a severe allergic reaction. L-arginine should not be used by those who have an allergy or hypersensitivity to it. Symptoms may include itching, rash, hives, shortness of breath and anaphylatic shock. If you experience any of these symptoms, seek medical attention immediately.

Toxic to the Brain

As the body breaks down L-arginine, it produces a gas known as nitric oxide that is left in the body in the blood vessels. This gas is required by the body because it is used in many basic body functions, such as penile erections, blood vessel dilation and neurotransmission between cells. However, if the L-arginine overproduces nitric oxide, it could be toxic to the body's brain tissue, states Drugs.com.

Medication Interaction

Using L-arginine with prescription medications could cause issues, so consult a physician before using it. Avoid L-arginine if you are using anti-hypertensive drugs, because it appears to decrease blood pressure and might take it too low. It should not be used if you are taking nitrates, which increase blood flow to the heart and may cause lightheadedness or dizziness. L-arginine should also be avoided if you are taking cholesterol lowering drugs or blood sugar regulators.