Guava has piqued people's curiosity since the early 1950s, particularly the leaves. The components that are useful in the numerous therapeutic characteristics demonstrated by Guava leaves have been identified. Guava leaves are utilized in a variety of traditional treatments.

Guava leaves have chemicals that can help with cancer, infections, inflammation, and pain, among other things. Guava leaf essential oil has shown to be very beneficial in treating cancer and other immunological disease prognoses.

Guava leaves are used to cure diarrhea, and the bark has antimicrobial and astringent properties. Dysentery and diabetes are also treated with leaves and bark. Guava is a fruit that originated in Peru and was farmed by the indigenous peoples, according to archaeological findings. The tree is widely distributed in rain forests, and as a result, it has a long history of use by rain forest natives, which continues to this day.

The Tikuna natives use a decoction of the leaves and bark to treat dysentery. The therapy is so successful that it is now being utilized by city dwellers as well. The Amazon Indians also use the leaves extract to treat diarrhea and as a gargle for sore throats, emesis, digestive problems, and menstrual irregularities. The leaves are often used to refresh the mouth and relieve toothaches. The extract from the leaves is also used as a douche for candidiasis and to tighten the vaginal walls, particularly after childbirth. Crushed leaves are applied to wounds and bruises. Flowers are crushed, and the extract is used in the eyes as eye drops to relieve the discomfort and burning associated with conjunctivitis or sun strain. Guava leaves have also been noted in an ancient Dutch pharmacopeia for their medicinal properties. The Dutch and other explorers took the fruit to other regions of the world. Guavas may now be found in almost every country in the world.

Saponins, carotenoids, lectins, flavonoids, essential oils, vitamins, tannins, phenols, triterpenes, fiber, and fatty acids are all abundant in guavas. It also has a far higher concentration of Vitamin C than oranges. It also contains a considerable amount of Vitamin A. Flavonoids like Quercetin is abundant in the leaves. These flavonoids are responsible for many of guava's therapeutic benefits. Guava leaves' antibacterial effect is also attributed to flavonoids.