Coleus Forskolii
Also known as: Plectranthus barbatus, Forskolin, Coleus forskohlii
Overview
Coleus forskohlii is a plant native to India and Southeast Asia, traditionally utilized in Ayurvedic medicine. Its primary bioactive compound, forskolin, is a labdane diterpene known for its ability to activate adenylate cyclase, thereby increasing intracellular cyclic AMP (cAMP) levels. This mechanism positions Coleus forskohlii as a botanical supplement with potential as a metabolic modulator and thermogenic agent. It is predominantly explored for its role in weight management, metabolic syndrome, and cardiovascular health, with some traditional uses extending to respiratory and fertility-related conditions. While research on Coleus forskohlii and forskolin is moderately developed, it is often constrained by small sample sizes and varied study designs. Evidence regarding its efficacy for weight loss and metabolic improvements remains mixed, and comprehensive systematic reviews are scarce, highlighting the need for further robust clinical investigation.
Benefits
Coleus forskohlii, primarily through its active compound forskolin, has shown several potential benefits, though the strength of evidence varies. For weight and fat loss, animal studies suggest a reduction in visceral fat and adipocyte size, but human studies show inconsistent effects on overall body weight, with high doses potentially reducing food intake but also causing adverse lipid changes. In terms of body composition, a randomized controlled trial in overweight men indicated that forskolin supplementation led to favorable changes, specifically increased lean body mass and decreased fat mass, without significantly reducing total body weight. This suggests a potential role in body recomposition rather than just weight loss. For metabolic syndrome, a double-blind randomized controlled trial found that forskolin significantly improved insulin levels and insulin resistance after 12 weeks in overweight/obese participants, although it did not significantly alter lipid profiles or appetite hormones. Beyond metabolic effects, forskolin may promote gastric and pancreatic secretions and exhibits vasodilatory properties, which could be relevant for conditions like erectile dysfunction, though clinical evidence for these applications is limited and preliminary.
How it works
Forskolin, the active compound in Coleus forskohlii, exerts its effects by directly activating adenylate cyclase, an enzyme crucial for converting ATP into cyclic AMP (cAMP). This activation leads to a significant increase in intracellular cAMP levels. Elevated cAMP then activates protein kinase A (PKA), a key enzyme that phosphorylates various proteins involved in cellular regulation. This cascade modulates several physiological processes, including lipolysis (fat breakdown), glucose metabolism, and smooth muscle relaxation. Specifically, increased cAMP levels contribute to the reduction of fat cell size, enhancement of insulin sensitivity, and cardiovascular effects such as vasodilation. The bioavailability of forskolin can vary by formulation, with its lipophilic nature suggesting that absorption may be improved when consumed with fats.
Side effects
Coleus forskohlii is generally well tolerated in clinical trials when used for up to 12 weeks, with no significant adverse events commonly reported. Minor changes in blood markers, such as increases in white blood cell counts and calcium levels, or decreases in ALT and uric acid, have been observed but typically remain within normal clinical ranges and are not considered concerning. However, caution is advised due to forskolin's known vasodilatory and hypotensive effects. This means there is a potential for interaction with antihypertensive medications, which could lead to excessively low blood pressure. Similarly, due to its potential effects on blood clotting, interactions with anticoagulants are theoretically possible, though these interactions are not yet well-studied in clinical settings. No significant contraindications have been identified for healthy adults. However, the safety of Coleus forskohlii has not been established for pregnant or lactating women, or for children, and its use in these populations is not recommended. Long-term safety data beyond 12 weeks of supplementation are also currently lacking.
Dosage
Clinical studies on Coleus forskohlii typically utilize a root extract standardized to contain 10% forskolin. The most common and effective dosage observed in research for metabolic effects is 250 mg of this standardized extract, taken twice daily. This translates to an approximate daily intake of 50 mg of pure forskolin. Higher doses, particularly those observed in animal studies, have been associated with adverse lipid effects, suggesting that the recommended human dosage range is important for both efficacy and safety. Given forskolin's lipophilic nature, taking the supplement with meals, especially those containing some fat, may enhance its absorption and bioavailability. There is currently no established maximum safe dose beyond the ranges studied in clinical trials, and comprehensive long-term safety data are still lacking. Adherence to the recommended dosage is crucial to minimize potential risks.
FAQs
Is forskolin safe?
Short-term use (up to 12 weeks) of forskolin appears safe in healthy adults, with side effects being rare and generally mild. Long-term safety data are still limited.
How quickly do benefits appear?
Clinical trials typically report observable benefits, such as improvements in body composition and insulin sensitivity, after approximately 12 weeks of consistent supplementation.
Can forskolin be combined with other supplements?
Limited data exist on combining forskolin with other supplements. Caution is advised, especially with those affecting blood pressure or metabolism, due to potential additive effects.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8000574/ – This source discusses preclinical animal studies on Coleus forskohlii, indicating that it can reduce visceral fat and adipocyte size in mice. However, it also notes that high doses may lead to adverse lipid changes, highlighting the importance of dose considerations.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC2129145/ – This randomized controlled trial (Godard et al., 2005) investigated forskolin's effects on overweight men. It found that supplementation increased lean body mass and decreased fat mass, but did not result in overall weight loss. The study reported no significant adverse effects, despite a small, male-only sample size.
- https://www.drugs.com/npp/forskolin.html – This source provides general information on forskolin, including its traditional uses and potential mechanisms. It touches upon its role in gastric and pancreatic secretions and vasodilatory effects, though it emphasizes the limited clinical evidence for these applications.
- https://onlinelibrary.wiley.com/doi/full/10.1002/ptr.5583 – This double-blind randomized controlled trial (Loftus et al., 2015) examined forskolin in overweight/obese adults. It concluded that 12 weeks of supplementation significantly improved insulin levels and insulin resistance, but did not alter lipid profiles or appetite hormones. The study noted the supplement was well tolerated.
