Forskolin is a naturally-sourced supplement that’s used to burn fat and suppress your appetite. For this reason, it’s an incredibly popular weight loss supplement, both on its own and in combination with other ingredients.
How does forskolin work, and is it worth taking? Our research team looked into the scientific research on forskolin to answer these exact questions. Here’s what we found.
1. Forskolin has been touted as the all-purpose miracle supplement
The well-known TV doctor Dr. Oz once famously called forskolin “lightning in a bottle” (1).
He was referring to its supposed powers as a weight-loss supplement but in reality, forskolin may have the power to help us in many more ways than just fat burning and looking sexy. Think: garcinia cambogia but potentially better.
If you take a look at the impressively long and varied list of what forskolin might be able to do for us, the first thing you notice is it seems to do wonderful things for a diverse set of ailments, which seemingly have nothing to do with each other.
2. Forskolin could decrease body fat
The so-called “Godard study” showed positive changes in bone mass and negative changes in fat mass in just 12 weeks, as well as a trend toward increased lean body mass (1).
Not only that, but serum free testosterone levels were significantly increased in participants, after taking forskolin. The men in the study took a 10% forskolin extract (250 mg) twice a day for 12 weeks. They were overweight and obese, so this tells us that coleus (forskolin) may be an effective treatment for obesity.
As for lean and fit men (and women) taking it in order to increase lean body mass and decrease body fat, there does not yet exist a clinical study as conclusive as this famous Godard study. We can draw connections and hope that in all likelihood that since this worked for obese men it would also work for women. It’s perfectly plausible and probably true.
3. Forskolin could also help with urinary tract infections
Turns out that UTIs, which are commonly treated with antibiotics to kill bacteria in the urinary tract, have a nasty habit of recurring. In one third of women who get UTIs, the infection comes back even when they undergo a full round of antibiotics (6).
The problem is how the bacteria behaves…specifically with how it interacts with cells in the bladder, where the infection occurs. Turns out E. coli, the bacteria in question, has the ability to adhere to receptors in bladder cells which, when triggered, release little sacs.
These sacs act to help the bladder expand when it gets full. The problem is, when the bladder is emptied and no longer needs to be expanded, these sacs go back into their “host” cells.
That’s when E. coli gets a free ride into the center of the bladder’s cells, where it’s sheltered from any antibiotics a woman might take. They can come back out any time, alive and well, causing the UTI to recur.
What’s that got to do with forskolin? Plenty, because what triggers those little empty sacs to come out is cyclic AMP. When c-AMP levels rise, the sacs come out and help the bladder expand.
4. Forskolin may help decrease your appetite
In the world of weight loss supplements, there are, broadly speaking, two strategies that a supplement can adopt to lead to weight loss.
Either it can increase your body’s energy expenditure (i.e. through fat oxidation or thermogenesis), or it can decrease your drive to eat more (as in appetite suppressants). Cross-disciplinary research appears to indicate that forskolin belongs to the latter category, at least according to a study published in the Journal of Functional Foods in 2015 (8).
The study used animal models to show that forskolin supplementation changed the levels of several key enzymes linked to the pancreas, and led to a decrease in appetite (measured as the amount of food consumed by the animals).
If these results translate to humans, it would explain the mechanism that forskolin uses to generate weight loss.
5. Forskolin probably works best when taken in the morning
These findings on appetite also give some insights into how to take forskolin—if its utility is mostly in its ability to modify your appetite, this would suggest that it is best to take forskolin in the morning, not at night.
That way, you would feel more full throughout the day, and would be less likely to overeat at lunch and at dinner.
In contrast, at night, you are less likely to benefit from the appetite suppressant effects of forskolin, as you won’t be taking in calories at night anyways. The real key to losing weight with an appetite suppressant is to shift the balance of energy intake and energy expenditure so you have a net caloric deficit, day after day.
Forskolin side effects
Most studies have not reported serious side effects. Forskolin has not been studied in an enormous number of clinical studies in humans, though studies so far have not reported serious side effects.
Forskolin can cause GI complaints like diarrhea. Gastrointestinal complaints like diarrhea have been reported in some studies, but like many new but understudied supplements, it’s hard to characterize the side effect profile of forskolin from the small number of clinical trials in the literature.
Up to 10% of people have mild side effects from forskolin. Fortunately, forskolin has been studied in a more innovative way using online surveys. A study published in 2019 in the journal Nutrients administered a survey to hundreds of users of a forskolin supplement to investigate the incidence of side effects (9).
The study showed a higher proportion of side effects than previously thought; fully ten percent of users of forskolin reported having some side effects. Gastrointestinal symptoms were the dominant side effect reported, and over 80% of these cases were diarrhea.
The authors suggested that, while forskolin can be an efficacious way to lose weight or keep it off, users should take the side effect profile into account when deciding whether to take this supplement.
One limitation of this survey-based study that should be kept in mind, however, is that it didn’t sample anyone who did not take forskolin—so some proportion of the incidence of side effects might be a “baseline level” of gastrointestinal symptoms that occur in people trying to lose weight.
Recent research suggests the optimal forskolin dosage is around 250 mg per day. The same innovative survey study we just discussed also provides useful population-level guidance on forskolin supplement dosing.
Because the survey collected so many respondents, the authors were able to fit a curve to the dosage taken and the incidence of negative gastrointestinal side effects.
Up to about 250 mg of forskolin per day, the rate of side effects was more or less negligible; it rose slowly from 250 to 500 mg, and more sharply for doses higher than 500 mg per day. Once the dosage level rose to 1000 mg per day, the incidence of diarrhea was estimated at over 20%, on average.
If you want a moderate weight loss effect and a low risk of gastrointestinal side effects, a dose of 250 mg of forskolin per day is a safe bet. If you are willing to accept a marginal risk of diarrhea (circa 5%) a dose of 500 mg per day might be worth a shot.
Avoid doses above 500 mg per day. Based on these surveys, though, doses above 500 mg per day seem like they are too likely to produce unhelpful side effects to be worth taking.
Even if you were to get a better weight loss effect, you’ll be unlikely to stick to a weight loss routine long-term if it generates very unpleasant side effects like diarrhea. So, in this case, it’s best to take a moderate dose for best results.
Forskolin benefits FAQ
Q: What is in forskolin?
A: Forskolin is a chemical compound that comes from the coleus plant, which is native to India. This molecule is extracted from raw plant material, purified, and packaged into capsules or tablets for use as a forskolin supplement.
Sometimes, you’ll find forskolin included alongside other compounds for weight loss, as in a diet pill, but technically speaking, forskolin refers to a single molecule.
Compare this to something like cranberry extract, where the concentration of active ingredients can vary widely from one supplement to another—in these situations, predicting efficacy is much harder.
Q: What are the dangers of taking forskolin?
A: Based on the admittedly limited clinical data, forskolin does not appear to have any major dangers associated with it, though it does seem to be associated with gastrointestinal side effects such as diarrhea.
New research shows that these dangers don’t really appear until doses of over 250 mg of forskolin per day, with the risk of GI tract disturbances growing exponentially when dosage is over 500 mg of forskolin per day. Aside from gastrointestinal symptoms, research thus far does not suggest that forskolin has any other undesirable effects.
Q: What plant does forskolin come from?
A: Forskolin is a chemical compound that comes from the plectranthus barbatus plant, more commonly known as Coleus forskohlii or simply coleus.
Forskolin is just a molecule that occurs in high concentrations in this particular plant, which is native to India and has been used in Ayurvedic medicine for centuries. Among its many possible applications, weight loss is by far the most common topic of research in recent years.
Related: Our best forskolin picks
Though the research to date is preliminary, forskolin shows some promise when it comes to losing weight. It appears to help maintain lean body mass and shed fat, in part by altering your metabolism and in part by acting as an appetite suppressant.
Forskolin has the least rate of side effects when taken at doses of 250 mg per day or less, though if you’re willing to tolerate a slight increase in side effects you can bump up the dose to 500 mg for a shot at more potent effects.