Scientists recruited 30 overweight subjects, 15 of which received 250 mg of 10% forskolin extract twice a day and 15 of which served as the placebo group. After 12 weeks, the forskolin group had the following results:

• Significantly elevated free testosterone levels (an increase of 16.77 +/- 33.77%, compared to -1.08 +/- 18.35% in the placebo group).
• Increased lean body mass.
• Increased metabolic rate.
• Significantly decreased body fat percentage and fat mass (as determined by DEXA).
• Lowered blood pressure.

Keep in mind, too, that the study didn't require the subjects to do any training or dieting. All of the fat loss and additional lean body mass happened on its own. Forskolin will, of course, work even better if you do combine it with lifting and conditioning work.

The scientists noticed that forskolin increased levels of cAMP (cyclic adenosine monophosphate). cAMP is an interesting compound because it acts as a kind of chemical switch that turns all kinds of body cells on and off.

For instance, increased levels of cAMP can cause the Leydig cells of the testicles to produce more testosterone, which in itself can lead to additional lean body mass. Increased levels of cAMP can also lead to the increased production of hormone-sensitive lipase (HSL), which leads to the release of free fatty acids to be used as fuel by the body.

This same chemical also upregulates the thyroid, causing some researchers to compare forskolin's effectiveness with thyroid-stimulating hormone (TSH).

As far as the reduced blood pressure seen in the test subjects, forskolin has long been credited with having a vasodilatory effect, which in itself reduces blood pressure. After all, when the pipes are wider, it's easier for fluid to get through them, and the pump doesn't have to work as hard.

Most compounds that exhibit a fat-burning effect do so by initiating a chemical reaction through receptors – a chemical group or molecule that receives signals from other chemicals or other stimuli in general. In most cases, receptors generally get de-sensitized to the original signal. Eventually, the signal either fails to initiate a response, or you need a stronger and stronger signal to get through.

But this isn't the case with forskolin because it's a "post-receptor agent." That means the fat-burning response shouldn't diminish over time. It should be just as effective the last day you take it as it was the first.

It does. While it won't increase their testosterone (at least by any mechanism I can see), it will activate cAMP, which will stimulate the thyroid and increase the release of free fatty acids through increased production of the enzyme HSL.

If you decide to experiment with forskolin's fat-burning, testosterone-increasing abilities, be sure to get your hands on a pharmaceutical-grade formula of carbonate ester. This extends the duration of action from 4 hours to 12 hours and increases bioavailability.

Carbolin-19® is the top choice. Take two to four capsules a day in two divided dosages. Allow at least four weeks before you judge its efficacy.

1. Godard MP et al. Body composition and hormonal adaptations associated with forskolin consumption in overweight and obese men. Obes Res. 2005 Aug;13(8):1335-43. PubMed.