Answer:
If you are asking about the medicinal uses there are many. It has been claimed that guave leaves can be used to treat tooth aches, diabetes, cancer etc.
Studies has shown guava leaf extract to be as effective as tetracycline in treating acute infectious diarrhea. it is claimed to also inhibit histamine release therefore an effective allergy treatment.
Guava leaves is rich in antioxidants which can help in cell repair from the effects of free radicals.