There are 9 words that start with 'isopr'.
| isoprene | isoprenes |
| isopropyl | isoprenoid |
| isopropyls | isoprenaline |
| isoprenalines | isoproterenol |
| isoproterenols | |
Note: These 9 words that start with 'isopr' are found from the USA & Canada version of the tournament Scrabble word list.