Plectranthus amboinicus, commonly known as Indian borage or Cuban oregano, has a long history of use in traditional medicine systems across South Asia, Africa, and the Caribbean for the treatment of coughs and related respiratory conditions. Traditional healers often recommend the fresh leaf juice, decoctions, or infusions to soothe coughs, colds, and throat irritation. The rationale is largely based on the plant’s aromatic, expectorant, and anti-inflammatory properties as observed in folk medicine. Ethnobotanical studies have repeatedly documented its use for cough in various cultures, supporting the claim of traditional usage.

Scientific studies on Plectranthus amboinicus are limited but a few in vitro and animal model investigations suggest that the plant contains compounds such as carvacrol, thymol, and eugenol, which possess antimicrobial, anti-inflammatory, and possibly bronchodilator effects. However, clinical trials in humans are lacking, and most of the available evidence is preclinical or anecdotal. Therefore, while the plant’s use for cough is well-established in traditional practices, scientific validation is incomplete and does not rise above preliminary pharmacological support.

In summary, the use of Plectranthus amboinicus for cough is justified by traditional evidence (rating: 3), but not yet strongly supported by rigorous scientific studies.