There are 14 words that start with 'lacta'.
| lactam | lactams | lactary | 
| lactase | lactate | lactases | 
| lactated | lactates | lactating | 
| lactation | lactations | lactalbumin | 
| lactational | lactalbumins | |
Note: These 14 words that start with 'lacta' are found from the USA & Canada version of the tournament Scrabble word list.