Sage is a folk remedy for hoarseness, sore throats and coughs, according to the National Center for Complimentary and Integrative Health. Sage is available as dried leaves, as an essential oil and in liquid sprays and extracts.
Sage is seen as a safe supplement, explains the National Center for Complimentary and Integrative Health; however, there are some species of sage that contain a substance called thujone, which can interfere with the nervous system. Extensive use of sage may also cause symptoms such as restlessness, seizures, kidney damage and vomiting. More than 12 drops of essential oil with sage is considered toxic. There have been no studies to look at the effect sage may have on other medications.
Scientifically, sage has not been studied as a treatment for hoarseness, states the National Center for Complimentary and Integrative Health. There have been studies, however, that show sage may improve the mood in young adults. It also may help to improve the memory of older adults. In addition, there has been research to indicate that sage works better than the placebo when used to enhance learning and thinking in those who suffer from Alzheimer's disease. There are also studies that show sage essential oil may have antimicrobial properties.