There are 17 words that start with 'hept'.
| heptad | heptads | heptane |
| heptose | heptagon | heptanes |
| heptarch | heptoses | heptagons |
| heptarchs | heptarchy | heptachlor |
| heptagonal | heptameter | heptachlors |
| heptameters | heptarchies | |
Note: These 17 words that start with 'hept' are found from the USA & Canada version of the tournament Scrabble word list.