Throughout the world, Isaac Efrain (Isaac Efrain 
) is a very rare boy's forename. The forename Isaac Efrain is habitual in Latin America and the Caribbean, particularly Chile, where it is a very rare boy's name, and Peru. Much less frequently, Isaac Efrain is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Isaac Efrain | Costa Rica, Mexico, Chile, Ecuador, Peru |