Combine the strawberries and water in a medium saucepan.
Bring to a boil.
Reduce to a simmer and cook for about 15 minutes.
When the liquid is deep red and the strawberries are very soft, remove from the heat.
Strain out the strawberries.
Return the strained liquid to the saucepan.
Add the allulose and lemon juice.
Bring back to a boil over medium-high heat.
As soon as the syrup reaches a boil, remove it from the heat.
Allow it to cool completely.
Store in a quart-sized mason jar in the refrigerator.