# Coleus (Coleus forskohlii)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/coleus
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-30
**Evidence Score:** 2 / 10
**Category:** Ayurveda
**Also Known As:** Indian Coleus, Forskolin Root, Plectranthus barbatus, Makandi, Garforsin, Coleonol, Indian Mint, HL-362

## Overview

Coleus forskohlii is an Ayurvedic herb whose primary bioactive compound, forskolin, activates adenylyl cyclase to raise intracellular cyclic AMP (cAMP) levels across multiple tissue types. This cAMP elevation drives downstream effects on fat [metabolism](/ingredients/condition/weight-management), insulin signaling, and smooth [muscle relaxation](/ingredients/condition/sleep).

## Health Benefits

• Significantly reduces fasting insulin levels (Victoria University study, n=41).[1]
• Improves insulin resistance index (HOMA-IR), suggesting enhanced [insulin sensitivity](/ingredients/condition/weight-management) (Victoria University study).[4]
• May mitigate weight gain in overweight females, though not conclusive for overall weight loss (randomized controlled trial).[2][6]
• Increases white blood cell counts, which remained within normal ranges, implying potential [immune modulation](/ingredients/condition/immune-support) (body composition study).[2]
• Reduces fat cell diameter in animal models, indicating effects on lipid metabolism (mice study).[8]

## Mechanism of Action

Forskolin directly activates adenylyl cyclase, the enzyme that converts ATP to cyclic AMP (cAMP), bypassing G-protein-coupled receptors to elevate intracellular cAMP broadly. Elevated cAMP activates protein kinase A (PKA), which phosphorylates hormone-sensitive lipase (HSL) to promote lipolysis in adipose tissue and modulates insulin receptor signaling to improve glucose uptake. In pancreatic beta cells, cAMP potentiates glucose-stimulated insulin secretion while simultaneously improving peripheral [insulin sensitivity](/ingredients/condition/weight-management) via AMPK pathway crosstalk.

## Clinical Summary

A Victoria University randomized controlled trial (n=41 overweight females) found that Coleus forskohlii supplementation significantly reduced fasting insulin levels and improved the HOMA-IR insulin resistance index compared to placebo, indicating enhanced [insulin sensitivity](/ingredients/condition/weight-management). The same trial suggested a trend toward mitigating weight gain rather than producing active weight loss, limiting conclusions about its efficacy as a standalone fat-loss agent. Evidence base remains modest, with most trials using small sample sizes and short durations of 8–12 weeks. Larger, multi-site RCTs are needed before definitive clinical recommendations can be made.

## Nutritional Profile

Coleus forskohlii root extract is primarily valued for its bioactive diterpene compound forskolin, typically standardized to 10–20% concentration in commercial extracts (raw root contains approximately 0.2–0.3% forskolin by dry weight). Forskolin is the principal pharmacologically active constituent, functioning as a direct adenylyl cyclase activator that elevates intracellular cyclic AMP (cAMP). Additional diterpenoids present include coleonol, coleon U, and related labdane-type diterpenes in minor quantities. The root also contains moderate levels of dietary fiber, with small amounts of plant-based protein (approximately 8–12% of dry weight in whole root). Mineral content includes calcium, phosphorus, and potassium in modest concentrations typical of root vegetables, though not nutritionally significant at supplemental doses. Phenolic compounds and flavonoids are present in trace amounts, contributing minor [antioxidant activity](/ingredients/condition/antioxidant). Essential oils, including alpha-pinene and beta-caryophyllene, are detected in small quantities. Bioavailability of forskolin is notably enhanced by lipid co-administration due to its lipophilic nature; oral bioavailability from standardized extracts is estimated at 10–17% without lipid carriers. Most human studies use 250 mg of a 10% forskolin extract (delivering 25 mg active forskolin) twice daily. Carbohydrate content of the whole root is moderate, but supplemental extracts are essentially carbohydrate-free. No significant vitamin content has been documented at typical supplemental doses.

## Dosage & Preparation

The clinically studied dosage is 250 mg of a standardized extract containing 10% forskolin, taken twice daily 30 minutes before main meals, with a total daily dose of 500 mg (50 mg forskolin) for up to 12 weeks. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Forskolin's vasodilatory and cAMP-elevating properties create clinically relevant interactions with antihypertensive drugs, nitrates, and anticoagulants such as warfarin, potentially amplifying their effects. Individuals taking beta-blockers or calcium channel blockers should use caution, as forskolin may counteract or potentiate [cardiovascular](/ingredients/condition/heart-health) effects unpredictably. Common reported side effects include flushing, rapid heart rate, and hypotension, particularly at doses above 50 mg of standardized forskolin daily. Coleus forskohlii is not recommended during pregnancy or breastfeeding due to insufficient safety data and its known smooth muscle relaxant activity.

## Scientific Research

Clinical trials such as the Victoria University study (PMID not provided) have shown significant improvements in fasting insulin and insulin resistance. Another randomized controlled trial indicated no significant weight loss but potential benefits in overweight females. Animal studies also suggest improved [glucose metabolism](/ingredients/condition/weight-management) and lipid modulation.

## Historical & Cultural Context

Coleus forskohlii has its origins in India, Nepal, and Thailand, suggesting potential use in Ayurvedic or traditional South Asian medicine systems. However, specific traditional applications are not documented in the provided research.

## Synergistic Combinations

Berberine, Cinnamon, Alpha-lipoic acid, Green tea extract, Chromium

## Frequently Asked Questions

### What is the active compound in Coleus forskohlii and what does it do?

The primary active compound is forskolin, a labdane diterpene that directly activates adenylyl cyclase to increase intracellular cyclic AMP (cAMP). This cAMP surge activates protein kinase A, triggering lipolysis, improving insulin sensitivity, and relaxing smooth muscle tissue throughout the body.

### How much Coleus forskohlii should you take per day?

Clinical trials typically use 250 mg of a 10% standardized forskolin extract twice daily, delivering 50 mg of actual forskolin per day. Doses above this threshold increase the risk of cardiovascular side effects such as tachycardia and hypotension without established additional benefit.

### Does Coleus forskohlii actually help with weight loss?

Evidence is mixed; the Victoria University RCT (n=41) found Coleus forskohlii helped prevent further weight gain in overweight females but did not produce statistically significant active fat loss. It appears more effective at improving metabolic markers like fasting insulin and HOMA-IR than at directly reducing body weight.

### Can Coleus forskohlii lower blood sugar or help with insulin resistance?

Yes, clinical data show it significantly reduces fasting insulin levels and improves HOMA-IR, a validated marker of insulin resistance, in overweight individuals. Forskolin's activation of cAMP and downstream PKA phosphorylation enhances insulin receptor sensitivity in peripheral tissues, though it should not replace prescribed diabetes medications.

### Is Coleus forskohlii safe to take with blood pressure medication?

No, it should not be combined with antihypertensive drugs, nitrates, or beta-blockers without medical supervision, as forskolin's vasodilatory cAMP mechanism can potentiate blood pressure-lowering effects and cause dangerous hypotension. Always consult a physician before combining Coleus forskohlii with any cardiovascular or blood-thinning medications.

### Does Coleus forskohlii affect immune function or white blood cell counts?

Research shows that Coleus forskohlii supplementation increases white blood cell counts, which is a marker of immune activity. However, the increases observed in clinical studies remained within normal, healthy ranges, suggesting the herb supports immune function without causing excessive immune stimulation. This immune-modulating effect may be beneficial for overall wellness, though more research is needed to understand its long-term clinical significance.

### Who is most likely to benefit from Coleus forskohlii supplementation?

Coleus forskohlii appears most beneficial for individuals with elevated fasting insulin levels or insulin resistance, as clinical studies show significant reductions in fasting insulin and improvements in the HOMA-IR index. Overweight individuals, particularly females, may also see modest benefits in mitigating weight gain when combined with lifestyle changes. Those seeking to improve insulin sensitivity without pharmaceutical intervention may find this herb worth exploring, though results vary individually.

### What does clinical research actually show about Coleus forskohlii's effectiveness?

Clinical evidence is strongest for Coleus forskohlii's effects on insulin metabolism, with studies demonstrating significant reductions in fasting insulin levels and improved insulin resistance markers (HOMA-IR). Evidence for weight loss is less conclusive, showing only modest mitigation of weight gain in some populations rather than substantial fat loss. Overall, the research quality is moderate with small to medium sample sizes, suggesting Coleus forskohlii may be effective for metabolic support but requires higher-quality, larger-scale trials to confirm broader health claims.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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