0001356576 2020-01-21 2020-01-21 false 0001356576 8-K 2020-01-21 Supernus Pharmaceuticals, Inc. DE 001-35518 20-2590184 1550 East Gude Drive Rockville MD 20850 301 838-2500 Common Stock, $0.001 par value per share SUPN NASDAQ false false false false false