Can You Take L-Arginine & Creatine Together?

When it comes to exercise performance, many athletes take sports supplements because they believe the supplements will give them an edge. Arginine and creatine are natural substances found in both the body and food that athletes commonly supplement. Some people assume that taking the two together will provide performance-enhancing benefits beyond what you'd get from supplementing one these supplements alone. Consult your doctor before making the decision to take supplements.

Arginine and creatine are two different, but related substances. Arginine is an amino acid found in foods like meat, poultry, fish, dairy, nuts and seeds. Your body uses it to make nitric oxide, which helps expand blood vessels and regulate blood flow. That's beneficial during exercise, when your muscles need more oxygen to work. Creatine, on the other hand, is a substance that provides energy to your muscles and plays a role in muscle growth.

In real-world performance, combining two beneficial substances doesn't always translate to improvements. There are no studies examining creatine and arginine together without other amino acids -- or comparing the supplements individually. But one study did evaluate creatine alone compared to creatine combined with arginine and other amino acids. Researchers found that creatine in combination with arginine and other amino acids was better than creatine alone at improving peak power output. This refers to the maximum amount of power you're able to generate over a short interval, or simply your all-out power. The study was published in the October 2008 edition of the International Journal of Sport Nutrition and Exercise Metabolism.

Consumers take creatine with arginine, most often as a preworkout combination, writes Jose Antonio, author of "Essentials of Sports Nutrition and Supplements." The strategy is to boost your strength and endurance to meet the demands of a rigorous workout. Powder blends containing both ingredients are available. You can also blend individual powders. It's typical to take it 30 minutes before working out, according to Antonio. Blend the powder with the liquid of your choice.

Taking dietary supplements may cause unwanted side effects. Long-term effects are unknown. The short-term effects of taking creatine, however, include muscle cramps, nausea, abdominal comfort and changes in bowel habits. Arginine may cause these same side effects. When starting supplements, monitor for any potentially worrisome side effects such as chest pains. Avoid arginine and creatine if you have kidney or liver problems as they may make your condition worse. Taking creatine increases your body's need for water. The amount of additional water you'll need depends on your creatine dose. For every 2 grams of creatine, you'll need an additional 8-ounce glass of water to remain hydrated, according to Antonio.