Quick view Doctors Best L-Arginine (Sustained + Immediate Release) - 120 Bilayer Tablets MSRP: $68.09 Now: $46.32 Was: Doctor's Best Sustained plus Immediate Release L-Arginine contains this essential amino acid in a bilayer tablet, with two tablets providing 1000mg, 500mg of sustained release and 500mg of... MSRP: $68.09 Now: $46.32 Was: Add to Cart Quick view Add to Cart