Yes, RESERPINE is a Scrabble word!

Letter values in Scrabble US: R 1, E 1, S 1, E 1, R 1, P 3, I 1, N 1, E 1.

Is it a valid word?

RESERPINE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

antihypertensive consisting of an alkaloid extracted from the plant Rauwolfia serpentina (trade names Raudixin or Rau-Sed or Sandril or Serpasil)

Also: rau-sed.

Not playable in Scrabble US: RAUDIXIN, SANDRIL, SERPASIL.