Does Green Coffee Work to Lose Weight in a Healthy Way?


The task of losing weight is complicated and that is why many people seek to make their way easier by consuming supplements. Green coffee extract is one of them and, currently, one of the most popular in the world. As the name implies, it is extracted from green coffee beans and contains a substance called chlorogenic acid, which is supposedly responsible for its effects on weight loss. This extract was promoted by Dr. Oz in 2012. This specialist is an American doctor famous for his television appearances, and is one of the best known “health gurus” in the world. But the truth is that most weight loss supplements never work as promised. So, it’s time to take a detailed look at the green coffee extract to see how it works and what science says about it.

What are Green Coffee Beans?

Green coffee beans are basically unroasted coffee beans. Coffee is naturally green, but it is usually roasted before being put on the market and that obscures it. Coffee beans are full of antioxidants and active pharmacological components. Two of the most important are caffeine and chlorogenic acid. The latter is the main active ingredient in green coffee beans, that is, the substance that makes weight loss effective. Unfortunately, most chlorogenic acid is lost once the coffee bean is roasted. Thus, regular coffee beans do not have the same effect (although there are also many good reasons to drink coffee).

In short: green coffee beans are the same as regular ones, except they have not been roasted. They have a high content of chlorogenic acid.

 How does Green Coffee Extract Work?

Green coffee beans contain a certain amount of caffeine. And several studies have shown that caffeine can accelerate the metabolism between 3 and 11%. However, the main active ingredient, it is believed, is chlorogenic acid. Some human studies suggest that chlorogenic acid may reduce the absorption of carbohydrates in the digestive tract, which lowers the level of blood sugar and insulin spikes. If this is so, drinking green coffee extract would be the same as eating a slightly low carb diet. Other studies (in rats) suggest that chlorogenic acid can reduce body weight, fat absorbed from the diet and fat stored in the liver, in addition to improving the functions of the fat-burning hormone adiponectin. Chlorogenic acid has also proven useful for improving cholesterol and triglyceride levels in rats.

In short: green coffee inhibits weight gain in animal studies. It is likely that this has to do with reduced carbohydrate absorption from the diet, or via other mechanisms. 

 What do Human Studies Say?

One of the human studies on green coffee extract included 30 overweight individuals for 12 weeks. They were divided into two groups: one consumed regular instant coffee, the other instant coffee enriched with 200 mg of this coffee extract. Neither group was instructed to change their exercise habits. The group that drank instant coffee with green coffee extract lost 5.4 kilos, while the group that drank only instant coffee lost 1.7 kilos. The percentage of body fat also dropped 3.6% in the group that consumed the extract, compared with 0.7% in the other group. Other studies have also reported significant weight loss in people who consumed green coffee extract. However, it is important to keep in mind that some of these studies were sponsored by companies that make money from the sales of the extract. This does not mean that the studies are not valid, but it is known that the source of funding for a study can have significant effects on its results. For this reason, it is a good idea to be skeptical about industry-funded research. Meanwhile, in 2011, a review of the evidence behind this coffee extract concluded that “the effects of these tests are promising, but the studies are of poor methodological quality. 

“More rigorous studies are needed to determine the usefulness of green coffee extract as a tool to lose weight”.

In summary: several controlled studies in humans show that green coffee extract can lead to significant weight loss. However, these studies were relatively small and some of them were financed by industries.

Do You Have Any Extra Health Benefits?

Green coffee can positively affect the way the body absorbs and uses carbohydrates. As hypothesized in animal studies, chlorogenic acid seems to reduce glucose absorption. This effect could play a protective role in diabetes management and explain the effects on weight. The coffee extract may also positively affect blood vessels, which impacts the health of the heart. Doses between 140-720 mg per day have been shown to lower blood pressure in both rats and humans with high blood pressure. And chlorogenic acid also works as an antioxidant. In short: green coffee extract improves glucose metabolism and reduces blood pressure. This could be beneficial for people at high risk of diabetes and heart disease.

 Side Effects, Dosage and How to Use it?

According to the limited amount of evidence available, green coffee extract seems to be quite safe. However, some participants dropped out of a study due to headaches and urinary infections. This study was too small to show if the side effects were caused by the supplement, it could have been just a coincidence. This coffee contains caffeine, which can have several side effects if consumed in large quantities. This includes anxiety, tremor and tachycardia. If you are sensitive to caffeine, be careful with green coffee extract.

Chlorogenic acid can have a laxative effect and cause diarrhea. 

Some people have had allergic reactions to green coffee beans. And the extract should be avoided if you have already had a coffee allergy. The safety of green coffee for pregnant women or breastfeeding women has not yet been tested, and should not be consumed by children. There are currently no studies that determine an optimal dose for coffee extract. However, the studies cited in this article used doses ranging from 120 to 300 mg of chlorogenic acid. Depending on the concentration of this substance in the supplement, the range can then range from 240 to 3000 mg of coffee extract per day. It is advisable to follow the instructions that accompany the product. A common instruction is to take a dose half an hour before each meal.


Green coffee extract seems to be useful as a weight loss aid. And it also seems to have benefits for glucose metabolism and blood pressure. However, many of the studies that prove it are small, short-term and usually sponsored by companies that produce or sell the extract. And the truth is that the only thing that proves to have good long-term results is the change of diet. Reducing carbohydrates and consuming more protein seems to be the most effective path, while emphasizing the consumption of unprocessed foods. However, This coffee extract may be worth the attempt. It may have a mild effect that can last for weeks or months, but you should not expect much more than that.



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