the 1hp and 5hp healing items don't heal 1 or 5 hp. I believe the 1 hp item heals about 15 hp. Haven't used the 5 hp one though.
I believe they are starting the game over again in Unity, they have another version that is much more advanced in story. In there the fighting system is completely different and you have a total of 10 hp, so those items heal 1 and 5 hp respectively in that version. So they just need to change it for this version.