Coleus Forskolii Root Extract
Also known as: Plectranthus barbatus, Coleus root extract, forskolin extract, Coleus forskohlii
Overview
Coleus forskohlii root extract is derived from the roots of the Coleus forskohlii plant, a traditional herb in Ayurvedic medicine. Its primary bioactive compound is forskolin, a labdane diterpene known for its ability to activate adenylate cyclase, thereby increasing intracellular cyclic AMP (cAMP) levels. This mechanism is central to its proposed effects on metabolism. The supplement is primarily marketed for its potential role in weight management, particularly fat loss, and for supporting metabolic and cardiovascular health. While several randomized controlled trials (RCTs) exist, the overall research maturity is moderate, with a notable absence of comprehensive systematic reviews or meta-analyses specifically on Coleus forskohlii root extract. The quality of evidence is mixed, with some smaller RCTs indicating modest effects on body composition and certain metabolic markers.
Benefits
Research suggests that Coleus forskohlii supplementation may offer benefits primarily related to body composition. Some randomized controlled trials (RCTs) have reported that in overweight and obese men, 12 weeks of supplementation can lead to a reduction in body fat percentage and an increase in lean body mass. However, these studies generally show no significant effect on overall body weight or BMI. Beyond body composition, forskolin may also contribute to improved lipid profiles and markers of liver function, such as decreased ALT and uric acid levels, without causing adverse cardiovascular effects. The most studied population for these benefits is overweight or obese adults, with limited data available for other demographics. While statistically significant, the observed effect sizes for fat reduction and lean mass increase have been modest, raising questions about their clinical significance. Benefits typically manifest over a 12-week supplementation period.
How it works
Forskolin, the active compound in Coleus forskohlii, exerts its effects primarily by activating adenylate cyclase. This enzyme's activation leads to an increase in intracellular cyclic AMP (cAMP) levels. Elevated cAMP plays a crucial role in modulating various cellular processes, including lipolysis (the breakdown of fats) and overall energy metabolism. By increasing cAMP, forskolin can enhance the activity of hormone-sensitive lipase, an enzyme critical for fat breakdown. Additionally, forskolin may influence cardiovascular function through vasodilation, although studies at typical supplement doses have not shown significant changes in heart rate or blood pressure. The bioavailability and absorption of forskolin are dependent on the specific formulation, with standardized extracts ensuring consistent active compound content.
Side effects
Coleus forskohlii root extract appears generally safe at commonly studied doses, such as 250 mg twice daily of an extract standardized for forskolin content. Controlled trials have not reported serious adverse events. While specific common side effects are not extensively documented, they seem minimal in clinical settings. Importantly, studies have shown no significant changes in heart rate or blood pressure, mitigating concerns about cardiovascular stimulation. However, due to forskolin's known pharmacological effects, caution is advised. It possesses vasodilatory properties and may affect platelet aggregation, which could theoretically interact with certain medications. Therefore, individuals with bleeding disorders or those taking anticoagulants should avoid its use. It is also contraindicated during pregnancy and lactation due to a lack of safety data. Insufficient safety data exists for special populations such as children and the elderly, warranting avoidance in these groups. No major drug interactions have been definitively reported, but the potential for interaction with blood thinners or blood pressure medications should be considered.
Dosage
The typical dosage of Coleus forskohlii root extract used in most clinical studies is 250 mg, taken twice daily, for a duration of 12 weeks. It is crucial that the extract is standardized to a specific forskolin content to ensure consistent potency and efficacy. While the minimum effective dose is not definitively established, this twice-daily regimen is commonly employed in research. There is no established maximum safe dose, and higher doses lack robust safety data. For optimal absorption, it is generally recommended to take the supplement with meals. Standardized extracts are preferred to guarantee a consistent amount of the active compound, forskolin, in each dose. No specific cofactors are known to be required for its absorption, but formulation can influence bioavailability.
FAQs
Is Coleus forskohlii effective for weight loss?
Evidence suggests modest reductions in body fat and increases in lean body mass, but not significant overall weight loss.
Is Coleus forskohlii safe to use?
It is generally considered safe at studied doses, with no serious adverse effects reported in controlled trials.
When is the best time to take Coleus forskohlii?
Studies commonly administer it twice daily with meals to potentially improve absorption.
How quickly can one expect to see effects?
Benefits, such as changes in body composition, are typically observed within 12 weeks of consistent supplementation.
Does Coleus forskohlii affect heart rate or blood pressure?
Controlled trials have not shown significant changes in heart rate or blood pressure at recommended dosages.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC2129145/ – This randomized controlled trial (Godard et al., 2005) investigated the effects of Coleus forskohlii extract (250 mg twice daily) in 30 overweight and obese men over 12 weeks. It found a significant decrease in body fat percentage and an increase in lean body mass, though no significant weight loss. The study also noted no adverse cardiovascular effects and stable blood markers, but was limited by its small, male-only sample.
- https://www.drugs.com/npp/forskolin.html – This source provides general information on forskolin, including its mechanism of action as an adenylate cyclase activator and its role in increasing cAMP. It discusses its bioavailability and absorption, noting that these factors can depend on the specific formulation of the supplement.
- https://clinicaltrials.gov/study/NCT02143349 – This entry describes a clinical trial (NCT02143349) evaluating 250 mg of Coleus forskohlii twice daily in overweight/obese adults over 12 weeks. The study aimed to measure effects on appetite, waist circumference, and blood lipids, adhering to RCT standards with a placebo control. Results were pending or unpublished at the time of this review.
- https://onlinelibrary.wiley.com/doi/full/10.1002/ptr.5583 – This review article on natural thermogenic agents (2016) discusses forskolin as a cAMP activator with potential to influence energy metabolism and weight management. It acknowledges the existing clinical evidence but characterizes its effects as mild and the overall evidence base as limited.
- https://www.ncbi.nlm.nih.gov/books/NBK576386/ – This source references a 2013 Cochrane review on obesity supplements, which included forskolin. The review noted a modest average weight loss of 1.1 kg over placebo for forskolin, but highlighted the lack of detailed analysis specifically on Coleus forskohlii extract, indicating a gap in comprehensive meta-analyses for this specific ingredient.