Plectranthus amboinicus, commonly known as Indian Borage or Cuban Oregano, has a long history of use in traditional medicine, particularly in South and Southeast Asia, for respiratory ailments including laryngitis, coughs, and sore throat. Traditional practitioners have recommended its leaves in the form of teas, decoctions, or as a chewed remedy to soothe inflamed throats and relieve hoarseness associated with laryngitis. The rationale for its use is largely based on its folkloric reputation for possessing anti-inflammatory, antimicrobial, and soothing properties, which are thought to help reduce irritation and infection in the throat and larynx.

Scientific studies have identified some bioactive compounds in Plectranthus amboinicus (such as carvacrol, thymol, and eugenol) that possess antimicrobial and anti-inflammatory activities in vitro. However, direct clinical evidence supporting its effectiveness specifically for laryngitis in humans is lacking. Most of the available research is preclinical and does not focus on laryngitis as an endpoint. Therefore, while its use is deeply rooted in tradition and supported by some plausible pharmacological actions, there is insufficient high-quality scientific evidence to confirm its efficacy for treating or supporting laryngitis.

As such, the use of Plectranthus amboinicus for laryngitis is justified by traditional medicine, and the supporting evidence is limited mainly to laboratory studies and ethnomedicinal reports rather than controlled clinical trials.