From the Super Mario Wiki
Point Swaps are items found in Paper Mario: The Thousand-Year Door. They are commonly sold at Glitzville Shop for five coins each. This item will allow Mario to switch his HP and FP. If one of those two stats are greater than the other's limit, it will not exceed it and will just stop at the maximum number of points allowed. Also, If Mario uses it himself when his FP is 0, he will receive a Game Over. If the player uses it on Mario's partner when his FP is 0, that partner will be KO'd.
Cooking an item with Point Swap often yields the item that restores the same amount of the other stat. The table below shows all the counterparts this item has to offer. Some combinations can also work in reverse. Point Swap recipes aren't recorded in the Recipes journal except for Poison Shroom.
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