Base Pair has released a new aptamer to L-Citrulline, a small, non-essential amino acid. Based on scientific reports that citrulline promotes muscle protein synthesis and improves blood flow, it has become a popular nutritional supplement. Because citrulline is produced in the small intestine, low citrulline levels are an indication of intestinal failure. Citrulline is metabolized in the kidneys. Elevated levels of citrulline are an indication of kidney failure. Visit the Citrulline Aptamer Page to learn more.