Dr. Oz doesn't know it but he’s responsible for a lot of the emails I get. For example, in a recent segment of the Dr Oz Show, an herb called Coleus forskohlii (also called forskolin) was said to be one of the secrets to weight loss. I first reviewed Coleus forskohlii in my book a few years ago, but in case you missed that chapter, let’s take a look at this herb and see if I can help you make sense of it. Does it help people lose weight? Let's look at the research and see what we can discover.
What is Coleus Forskohlii?
Coleus forskohlii, is a member of the mint family of herbs. Its technical name is Plectranthus barbatus. The roots of the plant contain a compound called forskolin. As such, coleus forskohlii and forskolin are often used interchangeably. Traditionally used in Ayurvedic medicine to treat asthma and other ailments, for the last several years, it’s the claims that forskolin helps weight loss that has sparked peoples interest the most. I've even seen Dr. Oz say “it works” when talking about forskoiln
Supplement Tip. If the name of the supplement that contains the prefix “fors” or forsk” (or something similar), it probably contains coleus forskohlii.
Coleus forskohlii has been in some products I've reviewed on this site. Some of those have included
Among others. See those reviews for additional information.
Coleus Forskohlii And Weight Loss
How does Coleus forskohlii help weight loss? Or rather, what is the theory behind how it’s supposed to work? This will get a little technical but bear with me, I promise to bring it home at the end.
Coleus forskohlii stimulates the production of a molecule called cyclic AMP (cAMP). In our body, cyclic AMP helps our cells talk to each other. When an increase or decrease in cAMP is detected, it acts as a signal that causes the body to do something.
One of the things that cAMP does is tell our cells to increase in an enzyme called hormone sensitive lipase—which burns fat. cAMP might also seems to stimulate the release of thyroid hormone which also helps burn fat and calories.
Translation: Coleus forskohlii (Forskolin) stimulates fat-burning enzymes and hormones which, in turn, causes weight loss.
The theory sounds good but is there any proof? It turns out there are a couple of Coleus forskohlii weight loss studies. Let’s take a look at them now.
Coleus Forskohlii Weight Loss Research
One study from 2005, titled Body composition and hormonal adaptations associated with forskolin consumption in overweight and obese men was published in the journal, Obesity Research.
This study looked at 30 overweight and obese men. Half of these men received Coleus forskohlii and half received a placebo. The people in this study took 250 mg of a supplement – called ForsLean that had 10 % Coleus forskohlii. They took the supplement twice a day (so 500 mg total per day). The study lasted 12 weeks.
ForceLean is a patented extract from the Sabinsa Corporation. ForsLean is in many coleus forskohlii products.
Body fat was determined via DEXA, a very accurate body fat measurement technique that uses x rays.
Those people getting Coleus forskohlii showed a reduction in body fat as well as an increase in testosterone.
Lean body mass (I take this to mean muscle) increased as well– but lean body mass also increased in the placebo group too. This could be a
problem with the study.
While lean body mass did increase more in those getting the Coleus forskohlii extract, how did the placebo (which should, in theory, do nothing) also increase lean body mass? This is a problem. The people in this study did not exercise. So if exercise didn’t cause the increase in lean body mass what did?
Another problem is that the people in the Coleus forskohlii group had higher testosterone levels at the start of the study than those in the placebo group. If the people were randomly divided into two groups, one would think that testosterone levels would be pretty much the same between the groups. But they were not.
This doesn't make sense.
As such, I'm not sure if coleus forskohlii raises testosterone or not.
Another observation was that Coleus forskohlii did not increase metabolic rate. This contradicts “experts” on the Dr Oz Show who have said that forskolin raises metabolic rate.
This particular study gets mentioned a lot on bodybuilding websites, however given the problems I just listed, I’d like to see another study to confirm these findings.
Another study, titled Effects of coleus forskohlii supplementation on body composition and hematological profiles in mildly overweight women was published in 2005 in the International Journal of the Society of Sports Nutrition.
In this study, 19 women were either given a Coleus forskohlii supplement –ForsLean – which contained 250 mg of a 10% Coleus forskohlii extract. The supplement was taken twice a day (so, 500 mg total per day was taken). The other group received a placebo and the study lasted 12 weeks.
Body fat was determined via DEXA scan which is a good indicator of body composition.
This study found that Coleus forskohlii did not promote any significant weight loss but it did seem to reduce the gaining of weight.
The forskolin extract did not seem to change thyroid hormone, liver enzymes, cholesterol, insulin, heart rate, blood pressure or red or white blood cells. This study unfortunately did not measure testosterone levels as the study above did.
So, while the Coleus forskohlii extract didn’t seem to help weight loss, it did appear to help people from gaining weight.
It is interesting supplement used in this study (ForsLean) is the same as that tested in the previous study. So, two studies on the same supplement each finding different outcomes.
These two human studies of Coleus forskohlii and weight loss appear to contradict each other in terms of whether Coleus forskohlii helps weight loss or not.
Based on this, maybe forskolin helps weight loss or maybe it might reduce the rate at which people gain weight. So which is it? I don’t think anyone has the answer at this time. This is a far cry from the proclamation of Dr Oz who said on his TV show “it works”.
In a 2014 study coleus forskholii was shown to curb appetite in rats fed a “cafeteria diet (basically they fed rats a lot of junk food). That's interesting and in theory, by curbing appetite, it might reduce gaining weight, which the previous study mentioned above noted. Still, this should be shown in human studies to know better what's going on.
Which Coleus Forskohlii Supplement Is Best?
There are a LOT of coleus forskohlii supplements out there. As such finding what may be the “best” can be daunting. So let me see if I can make the process a wee bit easier for you.
Some products make vague claims such as “raising metabolism” or boosting testosterone levels. But, from this review, claims like these are on shaky ground. As such, I recommend avoiding products that make claims like these.
Also avoid any ForsLean product that makes reference to Dr Oz. He has said this on his TV show too.
Remember coleus forskohlii and forskolin are the same thing. Different supplement companies call it by both names. Some brands may even call it by its scientific name: Plectranthus barbatus. This is important because this might confuse some people.
Most of the research is on the ForsLean brand.
Forslean is found in various coleus forskolii supplements either alone or in combination with other ingredients.
If it's going to work, ForsLean is the only ingredient that should be needed. There should be no need to combine coleus with
or any other trendy ingredients.
While studies often use 500 mg per day, given the lack of human research, its hard to know if this is the correct amount. As such, start with less to see if that works with you.
Coleus Forskohlii Side Effects
Based on the human studies done so far, Coleus forskohlii (forskolin) seems to be pretty safe in healthy people for at least 3 months.
Here are some things to consider when taking this supplement. This list is not complete.
- Start with less than is recommended for the first week to see how you respond.
- Some research using mice has noted coleus forskholii might alter an enzyme system called P450 which is involved in metabolizing a variety of medications. Because of this, people who take any medications should ask their pharmacist or doctor and specially ask questions relating to the P450 enzyme system. Your doctor /pharmacist will know exactly what you are talking about when you say “P450 enzyme.”
- Little research involves people who are not “healthy” and the herb may interact with medications like blood thinners. People with serious health issues like heart disease etc. should speak to their doctor before taking Coleus forskohlii.
- Stop all supplements at least 2 weeks before surgery.
- Speak to your doctor if you are pregnant or breastfeeding.
Does Coleus Forskohlii Work?
Despite the hype, I feel more research is needed to know if coleus forskohlii (forskolin) really works or not. As more research is done, we will have a better if it works. The research on forskolin is intriguing but it is far from conclusive. I do think coleus forskohlii is an interesting supplement but I can't yet say either way whether it helps people lose weight or not because I want to see a few more human studies.
If you have tried it and its helped you or not, I hope you will leave a comment below. On my personal website, I've written more about weight loss supplements that have evidence, along with other ideas that can help too.
Here is coleus forskohlii on Amazon
I just ordered the RHABDO book on your website, and I would love if you would autograph it!
Thanks Roseann and I will surely autograph it for you! 🙂
I agree with your concerns about the two human studies you talked about. Studies of small amounts of people, as these studies had very few participants, cannot be trusted to provide statistically significant results, especially when, as you mentioned in the men’s studies, the subjects aren’t really random. (The men in the study group had higher testosterone levels at the start of the study than did the men in the control group).
Some people mentioned that they got diarrhea when they took Foskolin. Maybe this is one of the ways that at first people lose weight-by dehydration? I’m just guessing.
Anyway, I agree with you that such small human studies, that aren’t really random selection, and that contradict each other are not adequate enough for any company to state that this product works to help people lose weight.
Hi Roseann, thanks for saying that. Diarrhea induced wt loss would be interesting for someone to take a look at.
I still see coleus forskohlii in supplements. I don’t know why. Given the lack of proof it works, the only reason I can think of is companies add it because its popular or “sexy.”
In the past, I bought so-called “Chinese Tea” for weight loss. The actions of these teas was to make the customer have diarrhea, which will lead to weight loss of a couple pounds. But that’s fake weight loss, because as soon as you replace the fluids and electrolytes you lost by drinking the tea, your weight is the same.
Congratulations to you- I just read that you wrote the first book on Rhabdo! I’m too disabled to exercise, so I’ll never encounter this very serious, sometimes fatal condition. I will buy your book to read about this condition because I have several nieces who run marathons, endurance runs, and other pretty excessive exercises. I’m concerned about one niece, who weighs 80 lbs! I’m an RN, BSN but I don’t know much about Rhabdo.
Hi Roseann, yes, those Chinese teas can be a mess! Generally they contain senna, which as you know is a laxative. Rhabdo yes! I made history with that book! 🙂 Besodes supplements, rhabdomyolysis is a topic Ive been lecturing about for over a decade. Ive met too many people who have gotten it from exercise.
My rhabdo book is on Amazon
Its on my personal website too and Ill even autograph if people like too.
wow your niece weighs 80 pounds! That’s not a lot.
I’m quite disabled, so I will never get RHABDO, but as a nurse, I’m very interested and will buy your ground-breaking book on the subject. My 80-lbs niece is a runner and triathlete. She thinks she is fat, so you and I know what that means. I hope she doesn’t read this ever, but we are all worried about her. Her sister is an endurance runner, and we saw her run in an 80-100 mile run in the Sierra Nevadas several years ago. She is a healthy weight. I’ll pass on your book or suggest they buy it after I read it. Congratulations for being an expert in this condition!
Thanks Roseanne, I can imagine how you area all worried about her at 80 pounds. Ive met people like that in the past. Its a challenge to get them to realize that they are not overweight. Pass it on to her hopefully it will help her. I designed it to be a pretty easy read.
I meant RHABDO!!
A bad speller once in a while,
No worries Roseann, I am too 🙂
its included in many weight loss products and can boost the effects of other fat loss compounds
Hi Kam, with respect, just because companies include coleus forskohlii does not mean it really works. it just means its trendy /popular. I’m still looking for good proof it actually works.
Elvin Reamey says
Thank you for you post. It seems very well done. In the paragraph containing the bold text “increases metabolic rate”, or something like that, the word “contracts” should be “contradicts”.
Elvin good eye thanks for catching that! I’ve corrected my typo 🙂
Hi, i’m a 13 year old boy who is 76 kg and 173 cm long, but i have obesity. Do you think that this will help at my age? Thank you for understanding
Hi Bart, I would not recommend coleus supplements. I dont feel there is enough evidence. Here is a list of things I do feel have evidence. This link goes to my personal website.
Remember that at 13 you are still growing and my guess is if you just eat better (less junk food if you are eating that), odds are your body fat will get better as you grow taller. I know at 13 there are stresses to “look good” but I want you to remember that you are special no matter what your weight is or what others say is overweight. I know that right now your metabolism is humming a long very nicely and so if you tried to eat more fruits, veggies, lean protein (chicken, turkey) and did a little bit of exercise like walking, jogging, push ups and stuff like that, that you would soon see changes in your body. You are at one of the best times of your life and for that reason I really dont feel weight loss supplements are something you need. Id rather you save your money, do some exercise and focus on how much your eating and what you are eating.
I hope some of this helps Bart. If you have any other questions, just ask and I will try to help.
Samantha Pitman says
I have just purchased a bottle of liquid CF. I’m taking 3ml,three times a day at a concentration of 1:1
It tastes bloomin awful so Im hoping there is a positive result for the torture I am about to endure for a few months. I’m 67.7kg and 44 Y/O. I will be on a high protein diet, and exercising 3 days /week.
I’ll let you know how I go. 🙂
Hi Samantha, thanks for chiming in and Ill look forward to hearing how things go for you 🙂
I started a diet program 8 days ago that included limiting calories to under 1500 daily, walking 3.5 miles every other day, and taking Forslean 250mg twice daily an hour before meals. I am a 52 year old male. I have lost approximately 9 pounds. I have continued taking daily supplements, a multi vitamin, vitamin D3 4000iu, and a probiotic during this diet. I also drink about 72 ounces of water daily.
I believe the Forkohlii supplement has helped because I have done this diet before and have averaged 4-5 pounds of weight loss weekly. The only possible side effect thus far is that I am mildly constipated. I believe that reducing caloric intake and exercise is necessary for this supplement to be effective, unless it is taken over an extended period of time.
I agree with you that to lose weight with this supplement you also need to reduce coloric intake and increase exercise. When I do all of these things together I also lose 4-5 pounds per week. I am a 40 year old female. One thing that sounds different for me is possible side effects as I have, very loose stools daily and frequently. I also tend to feel very hungry about an hour after taking 125mg of Forskolin.
I am a Caucasian female scientist who is 5’5″ and 46 years old. I only want to lose 5 pounds. It’s because I’m committed to an ideal number. I am well within my healthy weight range, but I thought I would try this product. I should also mention that until the last couple years I’ve had to work to gain bodyweight. The product I am using has 250 mg in two tablets which are standardized at 20% or 50 mg of forskolin per dose.
I have only been taking two tablets, the recommended dosage before one of my meals. I started out weighing 133 pounds. After a week I weigh 135 pounds. Interestingly enough I have never gone to the bathroom every single time I sit down to use the restroom. The first couple days I had diarrhea, but now I just go to the bathroom every time I use the restroom. And by that I mean I’m not just urinating.
I am not finding myself to be thirsty, but I am urinating more than usual. I generally drink a healthy amount of water and unsweetened iced tea.
I don’t particularly have a sweet tooth, however I have found that I do not want carbohydrates or sugar at all, I also have turn down drinks on the weekends. I actually enjoy bourbon, and this is interesting to me.
I’m also finding that it feels like my heart is beating up, but my monitor says it’s still in the 55 BPM range. I do not feel any changes with my Lexapro, which I’m taking for PTSD from an automobile accident, nor do I feel any changes from my thyroid medication, I have a very slight hypothyroidism. I am also on estrogen to balance my Depo-Provera shot, which I have been getting for over seven years.
As I have aged I have been sleeping less and less well, and experienced insomnia. I am waking up to use the restroom two or three times a night currently, but I’m able to go back to sleep, which is not common. I also feel that I have more energy during the day, and do not yearn for a nap like that usually do. I should tell you that I am getting a little less sleep than normally do, per my monitor.
I feel like I have given enough and information to assess. What do you think?
Ugh, sorry about the typos
You were good. I really didn’t see any 🙂
Hi Dyan, I’m honestly not sure. I know some people say coleus forskohlii helped them but I would like to see more human studies.
Dyan, I read your letter with much envy about your present weight and healthy lifestyle. I’m older than you are, and I’m at the age where losing weight seems impossible!! I was unsure, however, about what you were asking. Were you asking if frequent urination and bowel movements were a side effect?
As I’m sure you know and Joe also said, enzyme P450 metabolizes many medications. Can the C.F. Be interfering with the metabolism of your medications?
Does the CF you purchased have any other ingredients that could stimulate your CNS? I know you said your pulse remains at 55 bpm.
And do you check your weight every day at the same time per day?
The best time is first thing in the morning. If you only checked it once, the weight gain could be fluid retention.
I’m sorry to ask questions that are so simple, as you are a scientist, but I didn’t understand exactly what you were pointing out or asking in your comment. Why you didn’t lose weight? What is causing the side effects? Other reasons.
I hope you respond, because I’m really interested.
Oh, another thing-have you had your thyroid lab work done recently?
Lars Erik says
Ads for Forskolin come with “testimonies” by persons who do not exist. Just one example, they use an invented name and a photo of a model featured in the Daily Mirror (UK):
The article states that Charlotte Crosby reached her dream-weight by physical exercises and she sells a dvd to help other people do the same (and gain some money, of course).
You can check any photo in any “testimony” for any health supplement and there’s a great chance that you will get about the same result. Copy the picture of the “person” shown with the “testimony” to your hard disk, then open Google Image Search and use the copied picture. The same photo will appear in ads for other supplements and/or in other countries.
Hi Lars, yes you have touched on a scam that has been around for a long time – so called reports on celebs who lost weight using some dietary supplement. usually the story accompanies links to where people can buy the supplement. I didnt see any such links in the article you listed. It just looks like maybe this person turned a negative (gaining weight) into a positive (losing weight/selling a workout DVD).
Lars Erik says
Sorry, I didn’t present the complete result of my findings, so you read my posting backwards. The article in Daily Mirror is about the real person whose picture they are using in ads that Google repeatedly shows me, but with fake names. In other words, the ads are not stating that a celeb is using Forskolin (or any supplement), they have “invented” a “testimony” by a non-existing person but a celebrity photo.
Hi Lars, yes that also stuff happens online.
Hi Lars, I’ve seen this happen again and again with things like facial creams. It starts out saying that “Mary” from Stockton (or whatever city you live in) has infuriated plastic surgeons because she found out that combining two face creams made her look so young that she didn’t need plastic surgery!!!
This same ploy is used with supplements and other products, too. “Mary” is a single mother of two children who doesn’t have money to buy special face creams, but all of a sudden, she combined two that had special offers, and “Wow!! She looks 20 again!!” yeah, right! They use this same story over and over again, and it’s followed by a bunch of fake 1000000 star reviews.
I tried to write a review, but it wasn’t posted. I even called two of the companies that were involved, and they admitted that this is just an advertising scheme to get customers!! I guess this stupid scheme works because they keep doing it, and I’m sure there are plenty of stupid people who buy these “free samples-all you have to pay is S&H”. THAT IS ALL UNTIL the customer starts getting monthly shipments of these 2 face creams at prices like $49.95 EACH EVERY MONTH, with money taken out of their credit cards!!!!
When a customer calls to complain, the company tells them that’s what they signed up for-only it is in tiny print, way down in a place people usually don’t look! That is the SCAM of it all, and then try to get your money back!!!
Years ago I bought 2 products like this, but I caught the scam before they could start sending me monthly supplies. So I make an effort to tell people NOT TO GET their money stolen from them with these crooked schemes!!!
I read your article with interest because it has taken me years to identify the plant growing wild in my yard, which I started from a stick of it a few years ago. With the help of a plant nursery and a lot of research I was able to discover that I do indeed have Plectranthus barbatus (Coleus forskohlii) growing like a weed in my yard.
In researching the bush’s information I am discovering more and more of its fabulous health qualities. I have been wondering how I can actually put my plant to use in our family’so lives…..such as boiling leaves for teas or tinctures, using the roots in some way, etc. I know the plant has been used for thousands of years in different civilizations, but I cannot discover any information on how to use an actual plant to our benefit…. rather than purchasing supplements and such from others who have made items from the plant.
Do you have any leads to links where I can find more information regarding harvesting and using the plant? Thank you.
Hi Rasha, Im not sure how to harvest the plant. I wonder if someone who deals in plants could give you some insights.
I am an herbalist and often use a book by John Lust called The Herb Book for reference when using herbs. It tells you how to identify the plant, its benefits and what part of the plant to use medicinally. It even gives directions on how to prepare the herb for use.
Hi Sue, I saw 2 books by John Lust on Amazon
The Herb book (2009 reprinted edition)
The Herb Book 1974 edition
They look like they might be the same book. Which one do you use?
Lea B says
I have been taking Forskolin for about three weeks. It seems to be giving me diarrhea. When I stop taking it for a couple days, the problem stops, and when I resume taking it, the problem returns. I don’t see this mentioned as a side effect online.
Hi Lea B, GI problems (like diarrhea) and common side effects for many things. Its one of the reasons I often recommend starting any new supplement you take with the least amount possible for the first week, just to see how you respond.
Is there anything else in your forskolin supplement or is it just forskolin?
I am looking for a supplement that would help”Rev Up” my metabolism. I am 53 years old. What would you recommend?
Hi Libby, when you say “rev up” your metabolism, are you asking about this to help weight loss?
Are you doing any exercise? Exercise can help you burn calories and “rev up” your metabolism. When I say exercise, its important to know that even walking can do this. in fact, walking is a very good exercise with many health benefits.
As far as supplements are concerned, its my experience that products that are said to rev up metabolism, tend to contain stimulants, such as caffeine, bitter orange (synephrine) and others. I’m skeptical about the abilities of these things to promote weight loss. The research on them is iffy at best. Since they are stimulants, they might carry side effects which can be not safe in some people like elevating blood pressure. Because of that Im more of a fan of try to eat better (just a few less calories per day) and doing some type of exercise (like walking).
If you think your metabolism is low, have you ever had your thyroid checked? one thing Id mention is that metabolism is partially related to how much we weigh. In other words, heavier people tend to have higher metabolic rates than people who weigh less. I know that sounds contrary to what people think but it is true. Here is more on metabolism that might help shed light on this: http://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/metabolism/art-20046508
If you are thinking about weight loss, here is a list of things that I believe have some evidence. notice how many of them are fibers: http://www.joe-cannon.com/what-weight-loss-supplements-work/
If you have any other questions, just ask.
I am interested in the idea that coleos forskohlii helps with craving for sugar and carbs. Does it and if it does not is there anything that does? Thank you
Hi Jan, I dont recall seeing anything that it helps curbs cravings. The stuff that might curb appetite is fiber. Here is a list of things that have some evidence for weight loss. notice the number of products that are fiber.
gordon a sheriff says
i spent $ 160 plus $ 10 shipping for six monthly bottles. i took the caps daily as suggested and when
i took the last cap the only thing i lost was my money. i was going to return the last two bottles but did not want to pay the return postage. i did find out that forskohlii is good for the sinuses if tossed in the air and walked through breathing the dust particles in through your nose. worse decision i ever made.
Kurt Schreihart says
Per Web MD it can be inhaled to clear sinuses, the medical industry does use this for that as it relates to Asthma symptoms. Check this out on Web MD for all its approved medical purposes.