Guide
What is forskolin (Coleus forskohlii)? A plain guide
Forskolin is a compound extracted from the root of Coleus forskohlii, a mint-family plant used in Ayurvedic medicine; the supplement form is almost always a 10%-standardized extract, and its one well-studied mechanism (raising cellular cAMP) explains why it's been researched for several very different uses.
Forskolin is a compound extracted from the root of Coleus forskohlii, a plant in the mint family traditionally used in Ayurvedic medicine. It's sold as a capsule containing a standardized extract, most often 10% forskolin by weight. Its one well-studied mechanism — raising a signaling molecule called cAMP inside cells — is why it's turned up in research on several very different things.
Where it comes from
Coleus forskohlii is native to India, Nepal, Thailand and parts of East Africa, in the mint family (Lamiaceae). Its tuberous root has a long history in traditional Ayurvedic medicine, used historically for a wide range of complaints. In current botanical classification, the same plant is also referred to as Plectranthus barbatus — a name that shows up in some of the research literature, describing the identical species (PMID 20178070). The supplement ingredient is an extract made from that root, not the raw dried root itself.
What's actually in it, and how it's thought to work
Forskolin is one specific compound — a labdane diterpene — isolated from the root, and it's responsible for the extract's most-studied property: it directly activates an enzyme called adenylate cyclase, which raises levels of a signaling molecule called cyclic AMP (cAMP) inside cells. Because cAMP is involved in processes across many different tissues — fat cells, the eye's ciliary epithelium, heart muscle among them — forskolin has been studied in several unrelated contexts, not just one (PMID 20178070). Raising cAMP in a lab assay is a mechanism, not a guaranteed outcome from a capsule; see forskolin benefits: what the research does and doesn't show for what's actually been tested in people.
Forms it's sold in
Nearly all forskolin sold as a supplement is a standardized root extract, most commonly set to 10% forskolin by weight — meaning 250 mg of extract contains roughly 25 mg of the compound itself. The two published human trials on body composition both used this same standardization and amount: 250 mg of a 10% extract, taken twice a day (PMID 16129715, PMID 18500958). Some labels use a higher standardization percentage, which changes how much forskolin sits inside a given milligram count of "extract" — see how much forskolin should you take a day? for what that means when comparing two labels.
Why the form matters more than the mechanism
Because cAMP does something different depending on which tissue it's raised in, forskolin research doesn't transfer neatly from one form to another. Lowering eye pressure, for example, has been tested with a liquid suspension applied directly to the eye as drops — not a capsule that's swallowed (PMID 6132271, PMID 23023353). A drop placed on the eye and a capsule digested in the gut reach the body through completely different routes, so a finding about one doesn't tell you what the other does. See forskolin benefits: what the research does and doesn't show for what's actually been tested with the oral capsule form.
Questions people ask
What does forskolin do?
Inside the body, it raises cAMP by directly activating the enzyme that produces it (PMID 20178070). What that translates to for a person taking a capsule is a separate, narrower question, covered in forskolin benefits: what the research does and doesn't show.
How does forskolin work?
It activates adenylate cyclase, the enzyme that produces cyclic AMP, directly and without first needing to bind a cell-surface receptor — a more direct route than many hormones use to trigger the same kind of internal signal (PMID 20178070).
What is forskolin extract?
It's the standardized, concentrated form of the Coleus forskohlii root that's actually sold in capsules, typically set to 10% forskolin by weight. That's a different product from raw dried root, which isn't what most supplements contain.
What is forskolin root?
The root is the part of the plant the extract is made from — a tuberous underground root, harvested and processed to concentrate the forskolin compound before it's standardized and encapsulated.
Where does forskolin come from geographically?
Coleus forskohlii grows natively across India, Nepal, Thailand and parts of East Africa, and India remains a primary source for commercial extract production today.
Related reading: forskolin benefits: what the research does and doesn't show, how much forskolin should you take a day?, and how to choose a good forskolin.
Sources
- Plectranthus barbatus: a review of phytochemistry, ethnobotanical uses and pharmacology - Part 1 A 2010 phytochemistry review describes forskolin as the key adenylyl-cyclase-activating compound in Coleus forskohlii (also classified as Plectranthus barbatus), and notes that because natural forskolin doesn't dissolve well in water, a separate, modified water-soluble version was developed for cardiovascular research — a different, synthetic molecule, not the plant extract sold as a supplement.
- Body composition and hormonal adaptations associated with forskolin consumption in overweight and obese men A 2005 trial in 30 overweight or obese men used 250 mg of a 10% forskolin extract, twice a day, for 12 weeks — the standardization and dose referenced elsewhere on this site.
- Effects of coleus forskohlii supplementation on body composition and hematological profiles in mildly overweight women A 2005 trial in mildly overweight women used the identical extract and dose as the men's trial: 250 mg of a 10% forskolin extract, twice a day, for 12 weeks.
- Forskolin lowers intraocular pressure in rabbits, monkeys, and man A 1983 study found a single topical 1% forskolin eye-drop suspension significantly lowered intraocular pressure for several hours in healthy volunteers without eye disease — a liquid applied directly to the eye, not the oral capsules sold as a supplement.
- Forskolin: upcoming antiglaucoma molecule A 2012 review of forskolin as a glaucoma research candidate describes its cAMP-based mechanism for lowering eye pressure, tested topically as drops rather than as an oral supplement.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.