Pelargonium sidoides

Figure 1. The Pelargonium sidoides plant.

Pelargonium sidoides is a species of plant in the Pelargonium (Geranium) genus. Pelargonium sidoides is also known as Black Geranium, Umckaloabo, or Cape Pelargonium.

Pelargonium sidoides is a flowering plant native to South Africa and it is used as traditional medicine by the native populations of South Africa. The root of the plant is typically distilled into an extract and used in cough and cold remedies to alleviate symptoms and reduce the duration of illness, mainly for upper respiratory tract infections including the common cold, bronchitis, and sinusitis due to the ability of the extract to neutralise certain bacteria and viruses. However, there is insufficient scientific evidence to conclusively determine its efficacy in these applications.

Potential side effects of Pelargonium sidoides include stomach upset, nausea, heartburn, or worsening respiratory symptoms. In addition, Pelargonium sidoides contain a compound known as coumarin which acts as an anticoagulant (i.e. blood thinner), and should not be taken with prescribed coagulants or prior to surgery. Pelargonium sidoides may also trigger autoimmune symptoms thus should be used cautiously in people with autoimmune diseases like psoriasis, rheumatoid arthritis, lupus, and autoimmune hepatitis.