R6c - Ryu
- R6c - Ranexa
- Ranitidine - Regulin
- Reidispongiolide A - Retinoic Acid
- Retinol - Ribose 5-phosphate
- Ribose Phosphate - Riluzole
- Rimantadine - Robinul
- Robison Ester - Roxithromycin
- Rp1 - Ru85053
- Ru85493 - Ryu