This attractive, perennial member of the mint (Lamiaceae) family originated in the lower elevations of India. It is now grown around the world as an ornamental plant. The root is used medicinally.
Coleus should be avoided in people with ulcers, because it may increase stomach acid levels. Direct application to the eyes may cause transitory tearing, burning, and itching. The safety of coleus in pregnancy and breast-feeding is unknown.
Certain medications may interact with coleus:
Albuterol – Supportive interaction
Aspirin – Adverse interaction
Epinephrine – Supportive interaction
Salmeterol – Supportive interaction
Forskolin, found in coleus, may help dilate blood vessels and improve the forcefulness with which the heart pumps blood. A preliminary trial found that intravenous forskolin reduced blood pressure and improved heart function amongst people with cardiomyopathy [Arzneim Forsch 1987;37: pp.364-7]. It is unknown whether oral coleus extracts would have the same effect, but some herbalists recommend taking 200-600mg orally per day of a 10% forskolin extract.
Studies in healthy humans, including at least one double-blind trial, have shown that direct application of an ophthalmic preparation of forskolin to the eyes lowers eye pressure, thus reducing the risk of glaucoma. [Lancet 1983;1: pp.958-60, Klin Monatsbl Augenheilkd 1984;185: pp.522-6] Direct application of the whole herb to the eyes has not been studied and is not recommended.