Clayton's Health Facts: Forskolin.

Clayton South, SPN (ISSA), is a recognized expert in the bodybuilding / fitness industry with over 150 bodybuilding, fitness and nutrition publications to his credit.
1. What is it and where does it come from?

A plant used since antiquity in Hindu and Ayurvedic traditional medicine is the source of an amazing compound of unique biological importance. The plant, Coleus forskohlii, is where the compound forskolin comes from.

Forskolin has started showing up in many of the most advanced thermogenics and fat burners on the market due to it natural fat-loss-enhancing properties. Forskolin has also been touted as a life extension/longevity/anti-aging health product due to studies showing it's positive effects on the heart, lungs, and blood pressure.

2. What does it do and what scientific studies
give evidence to support this?

Forskolin has been shown to increase thyroid hormone production as well as stimulate thyroid hormone release. As we know, the thyroid is responsible for metabolic rate via the hormones it releases. Therefore, increasing production of the thyroid results in an increase in metabolism. But, that's not all forskolin is good for!

Over the centuries, Coleus has been used for a wide range of conditions such as cardiovascular disease, eczema, colic, insomnia, convulsions, painful urination and respiratory problems. It turns out that the active ingredient in this herb, Forskolin, is capable of beneficial action against a wide range of conditions. This is because it affects one of the most basic and important cell regulating compounds in the body: cyclic adenosine monophosphate (cAMP.)

Cyclic AMP is perhaps the most important cell-regulating compound. Once formed it activates many other enzymes involved in diverse cellular functions. Under normal situations cAMP is formed when a stimulatory hormone (e.g., epinephrine) binds to a receptor site on the cell membrane and stimulates the activation of adenylate cyclase. This enzyme is incorporated into all cellular membranes and only the specificity of the receptor determines which hormone will activate it in a particular cell. In the case of forskolin, it can aide in a number of biological processes, explained in further detail below.

Forskolin appears to bypass this need for direct hormonal activation of adenylate cyclase via transmembrane activation. As a result of this activation of adenylate cyclase intracellular cAMP levels rise. The physiological and biochemical effects of a raised intracellular cAMP level include: inhibition of platelet activation and degranulation; inhibition of mast cell degranulation and histamine release; increased force of contraction of heart muscle; relaxation of the arteries and other smooth muscles; increased insulin secretion; increased thyroid function; and increased lipolysis (fat destruction). Recent studies have found forskolin to possess additional mechanisms of action independent of its ability to directly stimulate adenylate cyclase and cAMP dependent physiological responses. Specifically forskolin has been shown to inhibit a number of membrane transport proteins and channel proteins through a mechanism that does not involve the production of cAMP. The result is again a transmembrane signaling that results in activation of other cellular enzymes.

Research is underway in the attempt to determine the exact receptors to which the forskolin is binding. Another action of forskolin is on antagonizing the action of platelet-activating factor (PAF) by interfering with PAF binding to receptor sites. PAF plays a central role in many inflammatory and allergic processes including neutrophil activation, increasing vascular permeability, smooth muscles contraction including bronchoconstriction, and reduction in coronary blood flow. After treatment of platelets with forskolin prior to PAF binding, a 30% to 40% decrease in PAF binding was observed. The decrease in PAF binding caused by forskolin was concomitant with a decrease in the physiological responses of platelets induced by PAF. However, this forskolin-induced decrease in PAF binding was not a consequence of cAMP formation as the addition of a cAMP analog could not mimic the action of forskolin.

By raising cAMP, forskolin is responsible for:

  • Inhibition of platelet activation factor (PAF) and degranulation.
  • Inhibition of mast cell degranulation and histamine release.
  • Increased force of contraction of heart muscle.
  • Relaxation of the arteries and other smooth muscle.
  • Increased insulin secretion.
  • Increased thyroid function.
  • Increased lipolysis (breakdown of fat)
Additionally, the inactive analog of forskolin, dideoxyforskolin, which does not activate adenylyl cyclase, also reduced PAF binding was due to a direct effect of this molecule and its analog on the PAF receptor itself or to components of the post receptor signaling for PAF. The therapeutic ramifications of c. forskohlii based on the pharmacology of forskolin are immense. There are many conditions where a decreased intracellular cAMP level is thought to be a major factor in the development of the disease process. At present C. forskohlii appears to be extremely well indicated in these types of conditions which include: eczema (atopic dermatitis), asthma, psoriasis, angina, and hypertension, as well as obesity. Forskolin works well as a fat-loss-aide stacked with ephedra because it counteracts the age-related decrease in response of fat cells to thermogenic (heat producing and calorie burning) agents like ephedrine.

3. Who needs it and what are some symptoms of deficiency?

Allergic conditions such as asthma and eczema are characterized by a relative decrease in cAMP in the bronchial smooth muscle and skin respectively. As a result of this derangement, mast cells degranulate and smooth muscle cells contract. In addition, these allergic conditions are also characterized by excessive levels of PAF. Current drug therapy for allergic conditions like asthma and eczema is largely designed to increase cAMP levels by using substances which either bind to receptors to stimulate adenylate cyclase (e.g., corticosteroids) or inhibit the enzyme phosphodiesterase which break down cAMP once it I formed (e.g., methyxanthines).

These actions are different then forskolin's ability to increase the initial production of cAMP via a transmembrane activation of adenylate cyclase. The cAMP elevating action of forskolin supports the use of C. forskohlii extracts used alone or in combination with standard drug therapy in the treatment of virtually all allergic conditions. Coleus forskohlii extracts may be particularly useful in asthma as increasing cellular levels of cAMP results in relaxation of bronchial muscles and relief of symptoms in asthma. Forskolin has been shown to have remarkable effects in relaxing constricted bronchial muscles in asthmatics. The bronchials are composed of what is known as smooth muscle. This type of muscle is also found in the gastrointestinal tract, uterus, bladder, and arteries.

Forskolin has been shown to have tremendous antispasmodic action on these various smooth muscles. This antispasmodic action of forskolin supports the long time use of C. forskohlii in the treatment of not only asthma, but also intestinal colic, uterine cramps (menstrual cramps), painful urination, angina, and hypertension. Forskolin's ability to relax smooth muscle in bronchial asthma is most probably due to an increase in cAMP, although forskolin has other anti-allergic activities such as inhibiting the release of histamine and the synthesis of allergic compounds.

The ancient medicinal plant Coleus forskohlii is the source of the compound forskolin which possesses unique biological activity. While clinical results are thought to be better obtained using the whole plant versus the isolated constituent forskolin, research on forskolin is upholding the traditional uses of the plant. Due to the unique pharmacology of forskolin, C. forskohlii may prove to be useful in a wide range of clinical conditions. Presently, it appears C. forskohlii is best suited for asthma, eczema, psoriasis, hypertension, congestive heart failure, and angina. It can be used alone, but it may prove to be most useful when combined with other botanicals and/or other measures in the treatment of these disorders.

4. How much should be taken? Are there any side effects?

The forskolin content of Coleus root is typically 0.2% to 0.3%, therefore the forskolin content of crude Coleus products may not be sufficient to produce a pharmacological effect. It is best to use standardized extracts which have concentrated the forskolin content. The recommended dosage should be based upon the level of forskolin. Future studies will undoubtedly produce more precise dosage recommendations of a Coleus forskohlii. The current recommendation for Coleus forskohlii extract, standardized to contain 185 forskolin, is 50 mg (9 mg of forskolin) two to three times daily. The animal studies on forskolin indicate an extremely low order of toxicity for forskolin. Based on the pharmacology of forskolin, it may be wide to restrict the use of C. forskohlii preparations in cases of low blood pressure and peptic ulcers. Furthermore, C. forskohlii preparations should be used with caution in patients on presription medications especially anti-asthmatics and anti-hypertensives due to its ability to possibly potentiate the drug's effect.

Check out the full article on Forskohlii that appeared in the Botanical Research Bulletin Vol.1, No. 6.