Plectranthus amboinicus, commonly known as Indian borage or Cuban oregano, has a long history of use in traditional medicine across Asia, Africa, and the Caribbean. In these systems, the plant’s leaves are often used in remedies intended to alleviate respiratory ailments, including sinus congestion, cough, and colds. The traditional rationale for its use in supporting the sinuses often centers on its aromatic, camphoraceous leaves, which are believed to help clear nasal passages and relieve symptoms of sinusitis when prepared as teas, inhalations, or poultices.

Some preliminary scientific studies have identified anti-inflammatory, antimicrobial, and antioxidant properties in extracts of Plectranthus amboinicus. For example, certain in vitro and animal studies have found that the essential oils and extracts may inhibit some respiratory pathogens and reduce airway inflammation. However, robust clinical trials in humans specifically evaluating its efficacy for sinus health are lacking. Thus, while there is a plausible basis for its traditional use, the overall strength of scientific evidence remains limited.

In summary, the use of Plectranthus amboinicus to support the sinuses is primarily rooted in traditional medicine, with some supportive but not definitive scientific findings. It is widely used in folk remedies but awaits more rigorous clinical validation.