Coleus

Also indexed as:Coleus forskohlii, Forskolin
Coleus: Main Image© Martin Wall
Botanical names:
Coleus forskohlii

How It Works

Forskolin, a chemical found in coleus, activates the enzyme adenylate cyclase.2 This enzyme is a turnkey compound that initiates a cascade of critical events within every cell of the body. Adenylate cyclase and the chemicals it activates comprise a “second messenger” system that is responsible for carrying out the complex and powerful effects of hormones in the body. Stimulation of the second messenger system by forskolin leads to blood vessel dilation,3 inhibition of allergic reactions,4 and an increase in thyroid hormone secretion.5 Forskolin has other properties as well, including inhibition of the pro-inflammatory substance known as platelet-activating factor (PAF)6 and inhibition of the spread of cancer cells.7

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,8, 9 thus reducing the risk of glaucoma. Direct application of the whole herb to the eyes has not been studied and is not recommended.

Forskolin may help dilate blood vessels and improve the forcefulness with which the heart pumps blood. A preliminary trial found that forskolin reduced blood pressure and improved heart function in people with cardiomyopathy.10 It is unknown if oral coleus extracts would have the same effect. A small double-blind trial found that inhaled forskolin could decrease lung spasms in asthmatics.11 It is unclear if oral ingestion of coleus extracts will provide similar benefits.

How to Use It

Coleus extracts standardized to 10 to 18% forskolin are available. While some doctors expert in herbal medicine recommend 50–100 mg two to three times per day of standardized coleus extract, these amounts are extrapolations and have yet to be confirmed by direct clinical research.12 Most studies have used injected forskolin, so it is unclear if oral ingestion of coleus extracts will provide similar benefits in the amounts recommended above. Until ophthalmic preparations of coleus or forskolin are available, people with glaucoma should consult with a skilled healthcare practitioner to obtain a sterile fluid extract for use in the eyes.

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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2024.