When you suffer from dry skin, damaged hair, or split ends, it can often be exacerbated by your own scratching and constant fiddling with your hair. The irritation of an unhealthy scalp can lead to damaged hair, which makes guava leaves such an effective remedy for this particular condition. Guava leaves can be boiled down and the resultant water can be applied to the scalp to reduce inflammation and protect against dry skin. This same water can then be applied to the hair in order to increase its shine and improve its overall health and thickness.