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Losing weight can be challenging. Studies show that about 25% of people with overweight who lose weight through conventional methods are able to maintain that loss (1).
Those who regain their lost weight are more likely to seek solutions such as dietary supplements and herbal medicines. One such supplement is forskolin, a natural plant compound that is said to be an impressive weight loss supplement. But does it really work?
This article takes a detailed look at forskolin and the science behind it.
What is forskolin?
As a weight loss supplement, forskolin gained popularity in the United States after being featured on “The Dr. Oz Show” in January 2014.
Forskolin is an active compound found in the roots of the Indian coleus (Coleus forskohlii), a tropical plant related to mint. For centuries, this plant has been used in traditional herbal medicine to treat various conditions and diseases (2).
Research now suggests that some of this compound’s potential health benefits — such as relief of cough, asthma symptoms, insomnia, and skin diseases — may be legitimate, or at least plausible (3, 4).
How do weight loss supplements work?
Weight loss supplements can allegedly promote weight loss in several ways, including by (5):
- reducing nutrient absorption
- increasing the breakdown of fats
- boosting energy expenditure
- reducing hunger levels
Because your body needs to break down nutrients in order to absorb them, supplements that reduce nutrient absorption often target different enzymes in charge of nutrient digestion.
For instance, some supplements block an enzyme called pancreatic lipase, which reduces fat absorption. In contrast, others inhibit enzymes such as amylase and glucosidase, preventing the digestion and absorption of carbs.
In both cases, the supplement promotes weight loss by reducing energy intake (5).
Furthermore, supplements that increase the breakdown of fats — also known as fat burners — reportedly work either by reducing fat accumulation or by preventing the formation of fat, a process called lipogenesis (6).
Supplements that boost your energy expenditure, such as caffeine, mostly rely on their thermogenic effect — an ability to produce heat.
This leads to an increased resting energy expenditure — the number of calories your body burns while resting — and thus promotes fat loss (7).
Lastly, supplements that help reduce hunger act by increasing the levels of hormones that promote feelings of fullness, such as peptide YY (PYY) and glucagon-like peptide-1 (GLP-1), and reducing the levels of hunger-promoting hormones such as ghrelin (5).
Does forskolin actually help you lose weight?
While some studies have investigated the effects of forskolin on fat metabolism, most have been test-tube experiments or animal studies, so their results may not apply to humans. Recent human research is scarce.
Forskolin is believed to promote the production of hormone-sensitive lipase, an enzyme involved in moving stored triglycerides and releasing fatty acids so your body can use them for energy (8).
In simple terms, forskolin is thought to reduce the size of fat cells by promoting the breakdown of fats. The same happens whenever your body needs to use fat as fuel (2).
Nevertheless, the release of stored fat is not enough to promote weight loss on its own. It needs to be accompanied by a calorie deficit.
In other words, for weight loss to happen, energy expenditure (calories out) must exceed energy intake (calories in), which is precisely what was determined in a small 2015 study (9).
The researchers recruited 30 men with overweight or obesity. Twice a day for 12 weeks, the participants took either 250 mg of Coleus forskohlii extract (10% forskolin) or a placebo.
At the end of the trial, there were no significant weight loss differences between the groups. However, both groups showed reductions in waist and hip circumference, which were attributed to the calorie restriction rather than to forskolin (9).
Nonetheless, an older 2005 study in 30 men with overweight or obesity suggested that forskolin may promote fat loss while preserving muscle mass (10).
There was also a significant increase in free testosterone in the forskolin group. Testosterone can stimulate the release of fat from fat cells and promote an increase in muscle mass, which may partly explain the study’s results (10, 11).
All that being said, the current evidence is not strong enough to make any recommendations. More research is needed (12).
Other health benefits of forskolin supplements
The Indian coleus plant (which contains forskolin) has been a part of traditional herbal medicine for centuries.
It has been used to treat conditions such as heart ailments, asthma, bronchitis, and constipation (13).
In humans, forskolin supplements may also (8, 9, 14):
- reduce fasting blood insulin levels and insulin resistance
- lower high blood pressure
- lower high pressure within the eyeball
Dosage and side effects
The typical dosage of forskolin is 10–25 mg of Coleus forskohlii (10% forskolin) twice per day (15).
While forskolin is recognized as safe and typically well tolerated, some users have reported gastrointestinal side effects such as diarrhea (9, 16).
Frequently asked questions about forskolin
What are the dangers of taking forskolin?
As mentioned above, forskolin is generally safe to use. However, some people may experience diarrhea after consuming it (9, 16).
Researchers believe this side effect happens because forskolin increases the production of acid in your stomach, which may increase bowel movements and loose stools.
Forskolin-induced diarrhea appears to be mild, and symptoms reportedly disappear within 4 weeks of use (9).
Can forskolin raise blood pressure?
According to recent scientific research, forskolin may actually help lower blood pressure.
Evidence suggests that it works via vasorelaxation. This means that it widens blood vessels, such as veins and arteries, by promoting the relaxation of the muscles within their walls, thus improving blood circulation (8).
Is forskolin good for your heart?
In addition to having a blood pressure-lowering effect, forskolin is used as a treatment for heart failure.
Research shows that it can activate or boost a chemical messenger called 3′-5′-cyclic adenosine monophosphate (cAMP), which plays a key role in heart function by controlling both heart rate and the strength of the heart’s contractions (8, 17, 18).
However, research assessing the benefits of forskolin for heart health in humans is limited. Therefore, be sure to consult with a healthcare professional before consuming it.
The bottom line
Based on the current evidence, it is unclear whether forskolin promotes weight loss.
However, one study published in 2005 suggests that it may raise testosterone levels and promote fat loss while increasing muscle mass.
At this point, the evidence is much too limited to draw meaningful conclusions.
As a general rule, it is a good idea to be skeptical of weight loss supplements. Some of them show promise in early studies, only to be proven completely ineffective in larger, higher quality studies.
The healthiest approach to weight loss tends to be one that modifies your diet to improve your overall health — often, weight loss will follow.