Jarrow Formulas® Arginine-Citrulline Sustain™ combines two essential amino acids to help sustain nitric oxide (NO) levels, enhance blood flow and promote cardiovascular health.* L-Citrulline converts to L-Arginine, thereby boosting L-Arginine levels and NO production.* Arginine-Citrulline Sustain™ ensures these amino acids are available in your system for up to 8 hours.*