Having used both, i found them indistinguishible with respect to their effect on me. The generic form that I used is made by the TEVA company in Israel. Teva also makes Sinemet for Merck for yhe latters markets abroad. I understand that TEVA sends material from a common pot to a round pelleting machine and a second line to apelleting machine whichgives out the soaplike shape we all know. Sam Kalkstein