Pill Identification by Imprints: M 1840 Home Pill Identification by Imprints: M 1840 1 result METHYLPHENIDATE ER 40 MG CAP Side 1: M 1840 Color: Yellow Side 2: 40 mg Shape: Oblong Other Popular Drug Imprint SV2 PH051 NAPROSYN Watson 629 M C3 93 D AN 55 PLIVA 333 G 171 PROVIGIL I 7 13 30 ACN 8 N 40 44 178 P0 02 554 260 3571 V ZE 49 1206 M 1840 SOMA 250 609 NP 20 54 455 SG VP302 MYLAN 6089 GG 490 V209 logo and 2891 R50 B198 R531 M451 B 01 FX100 MYLAN 8021 CLEOCIN 300 mg