What is it?
Green coffee became popular for weight loss after it was mentioned on the Dr. Oz show in 2012. The Dr. Oz show referred to it as "The green coffee bean that burns fat fast" and claims that no exercise or diet is needed.
People take green coffee by mouth for obesity, diabetes, high blood pressure, Alzheimer's disease, and bacterial infections.
How effective is it?
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
The effectiveness ratings for GREEN COFFEE are as follows:
Insufficient evidence to rate effectiveness for...
- High blood pressure. Early research suggests that taking green coffee extracts containing 50 mg to 140 mg of chlorogenic acids daily for 4 weeks to 12 weeks can reduce blood pressure in Japanese adults with mild and untreated high blood pressure. Systolic blood pressure (the top number) appears to be reduced by 5 mmHg to 10 mmHg. Diastolic blood pressure (the bottom number) appears to be reduced by 3 mmHg to 7 mmHg.
- Obesity. Early research shows that adults with obesity who take a specific green coffee extract (Svetol, Naturex) five times daily for 8 weeks to 12 weeks, either alone or together with the regular coffee product Coffee Slender (Med-Eq Ltd., Tonsberg, Norway), lose an average of 2.5 to 3.7 kg more weight than people taking a placebo or regular coffee by itself.
- Alzheimer's disease.
- Type 2 diabetes.
- Other conditions.
How does it work?
For weight loss, chlorogenic acid in green coffee is thought to affect how the body handles blood sugar and metabolism.
Are there safety concerns?
It is important to understand that green coffee contains caffeine, similar to regular coffee. Therefore, green coffee can cause caffeine-related side effects similar to coffee.
Caffeine can cause insomnia, nervousness and restlessness, stomach upset, nausea and vomiting, increased heart and breathing rate, and other side effects. Consuming large amounts of coffee might also cause headache, anxiety, agitation, ringing in the ears, and irregular heartbeats.
Special precautions & warnings:Pregnancy and breast-feeding: There is not enough reliable information about the safety of taking green coffee if you are pregnant or breast feeding. Stay on the safe side and avoid use..
Abnormally high levels of homocysteine: Consuming a high dose of chlorogenic acid for a short duration has caused increased plasma homocysteine levels, which may be associated with conditions such as heart disease.
Anxiety disorders: The caffeine in green coffee might make anxiety worse.
Bleeding disorders: There is some concern that the caffeine in green coffee might make bleeding disorders worse.
Diabetes: Some research suggests that caffeine contained in green coffee might change the way people with diabetes process sugar. Caffeine has been reported to cause increases as well as decreases in blood sugar. Use caffeine with caution if you have diabetes and monitor your blood sugar carefully.
Diarrhea: Green coffee contains caffeine. The caffeine in coffee, especially when taken in large amounts, can worsen diarrhea.
Glaucoma: Taking caffeine which is contained in green coffee can increases pressure inside the eye. The increase starts within 30 minutes and lasts for at least 90 minutes.
High blood pressure: Taking caffeine found in green coffee might increase blood pressure in people with high blood pressure. However, this effect might be less in people who consume caffeine from coffee or other sources regularly.
High cholesterol: Certain components of unfiltered coffee have been shown to increase cholesterol levels. These components can be found in green coffee as well. However, it is unclear if green coffee can also cause increased cholesterol levels.
Irritable bowel syndrome (IBS): Green coffee contains caffeine. The caffeine in coffee, especially when taken in large amounts, can worsen diarrhea and might worsen symptoms of IBS.
Thinning bones (osteoporosis): Caffeine from green coffee and other sources can increase the amount of calcium that is flushed out in the urine. This might weaken bones. If you have osteoporosis, limit caffeine consumption to less than 300 mg per day (approximately 2-3 cups of regular coffee). Taking calcium supplements may help to make up for calcium that is lost. Postmenopausal women who have an inherited condition that keeps them from processing vitamin D normally, should be especially cautious when using caffeine.
Are there interactions with medications?
- Adenosine (Adenocard)
- The caffeine in green coffee might block the effects of adenosine (Adenocard). Adenosine (Adenocard) is often used by doctors to do a test on the heart. This test is called a cardiac stress test. Stop consuming green coffee or other caffeine-containing products at least 24 hours before a cardiac stress test.
- The body breaks down the caffeine in green coffee to get rid of it. Alcohol can decrease how quickly the body breaks down caffeine. Taking green coffee along with alcohol might cause too much caffeine in the bloodstream and caffeine side effects including jitteriness, headache, and fast heartbeat.
- Alendronate (Fosamax)
- Green coffee might decrease how much alendronate (Fosamax) the body absorbs. Taking coffee and alendronate (Fosamax) at the same time can decrease the effectiveness of alendronate (Fosamax). Don't take green coffee within two hours of taking alendronate (Fosamax).
- Antibiotics (Quinolone antibiotics)
- The body breaks down caffeine from green coffee and other sources to get rid of it. Some antibiotics might decrease how quickly the body breaks down caffeine. Taking these antibiotics along with green coffee can increase the risk of side effects including jitteriness, headache, increased heart rate, and other side effects.
Some antibiotics that decrease how quickly the body breaks down caffeine include ciprofloxacin (Cipro), enoxacin (Penetrex), norfloxacin (Chibroxin, Noroxin), sparfloxacin (Zagam), trovafloxacin (Trovan), and grepafloxacin (Raxar).
- Clozapine (Clozaril)
- The body breaks down clozapine (Clozaril) to get rid of it. The caffeine in green coffee might decrease how fast the body breaks down clozapine (Clozaril). Taking green coffee along with clozapine (Clozaril) can increase the effects and side effects of clozapine (Clozaril).
- Dipyridamole (Persantine)
- The caffeine in green coffee might block the effects of dipyridamole (Persantine). Dipyridamole (Persantine) is often used by doctors to do a test on the heart. This test is called a cardiac stress test. Stop taking green coffee or other caffeine-containing products at least 24 hours before a cardiac stress test.
- Disulfiram (Antabuse)
- The body breaks down the caffeine in green coffee to get rid of it. Disulfiram (Antabuse) can decrease how quickly the body gets rid of caffeine. Taking green coffee along with disulfiram (Antabuse) might increase the effects and side effects of coffee including jitteriness, hyperactivity, irritability, and others.
- Stimulant drugs speed up the nervous system. The caffeine in green coffee and ephedrine are both stimulant drugs. Taking green coffee and ephedrine might cause too much stimulation and sometimes serious side effects and heart problems. Do not take caffeine-containing products and ephedrine at the same time.
- The body breaks down the caffeine in green coffee to get rid of it. Estrogens can decrease how quickly the body breaks down caffeine. Taking estrogen pills and green coffee might cause jitteriness, headache, fast heartbeat, and other side effects. If you take estrogen pills limit your caffeine intake.
Some estrogen pills include conjugated equine estrogens (Premarin), ethinyl estradiol, estradiol, and others.
- Fluvoxamine (Luvox)
- The body breaks down the caffeine in green coffee to get rid of it. Fluvoxamine (Luvox) can decrease how quickly the body breaks down caffeine. Taking caffeine along with fluvoxamine (Luvox) might cause too much caffeine in the body, and increase the effects and side effects of caffeine.
- Your body naturally gets rid of lithium. The caffeine in green coffee can increase how quickly your body gets rid of lithium. If you take products that contain caffeine and you take lithium, stop taking caffeine products slowly. Stopping caffeine too quickly can increase the side effects of lithium.
- Medications for asthma (Beta-adrenergic agonists)
- Green coffee contains caffeine. Caffeine can stimulate the heart. Some medications for asthma can also stimulate the heart. Taking caffeine with some medications for asthma might cause too much stimulation and cause heart problems.
Some medications for asthma include albuterol (Proventil, Ventolin, Volmax), metaproterenol (Alupent), terbutaline (Bricanyl, Brethine), and isoproterenol (Isuprel).
- Medications for depression (MAOIs)
- The caffeine in green coffee can stimulate the body. Some medications used for depression can also stimulate the body. Taking green coffee and taking some medications for depression might cause too much stimulation and serious side effects including fast heartbeat, high blood pressure, nervousness, and others.
Some of these medications used for depression include phenelzine (Nardil), tranylcypromine (Parnate), and others.
- Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
- Caffeine in green coffee might slow blood clotting. Taking green coffee along with medications that also slow clotting might increase the chances of bruising and bleeding.
Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.
- Pentobarbital (Nembutal)
- The stimulant effects of the caffeine in green coffee can block the sleep-producing effects of pentobarbital.
- The caffeine in green coffee can stimulate the body. Phenylpropanolamine can also stimulate the body. Taking caffeine and phenylpropanolamine together might cause too much stimulation and increase heartbeat, blood pressure, and cause nervousness.
- Riluzole (Rilutek)
- The body breaks down riluzole (Rilutek) to get rid of it. Taking green coffee can decrease how fast the body breaks down riluzole (Rilutek). In theory, combined use might increase the effects and side effects of riluzole.
- Stimulant drugs
- Stimulant drugs speed up the nervous system. By speeding up the nervous system, stimulant medications can make you feel jittery and speed up your heartbeat. The caffeine in green coffee can also speed up the nervous system. Taking green coffee along with stimulant drugs might cause serious problems including increased heart rate and high blood pressure. Avoid taking stimulant drugs along with green coffee.
Some stimulant drugs include diethylpropion (Tenuate), epinephrine, phentermine (Ionamin), pseudoephedrine (Sudafed), and many others.
- The caffeine in green coffee works similarly to theophylline. Caffeine can also decrease how quickly the body gets rid of theophylline. Taking green coffee and taking theophylline might increase the effects and side effects of theophylline.
- Verapamil (Calan, Covera, Isoptin, Verelan)
- The body breaks down the caffeine in green coffee to get rid of it. Verapamil (Calan, Covera, Isoptin, Verelan) can decrease how quickly the body gets rid of caffeine. Drinking coffee and taking verapamil (Calan, Covera, Isoptin, Verelan) can increase the risk of side effects for green coffee including jitteriness, headache, and an increased heartbeat.
- Birth control pills (Contraceptive drugs)
- The body breaks down the caffeine in green coffee to get rid of it. Birth control pills can decrease how quickly the body breaks down caffeine. Taking green coffee along with birth control pills can cause jitteriness, headache, fast heartbeat, and other side effects.
Some birth control pills include ethinyl estradiol and levonorgestrel (Triphasil), ethinyl estradiol and norethindrone (Ortho-Novum 1/35, Ortho-Novum 7/7/7), and others.
- Cimetidine (Tagamet)
- The body breaks down the caffeine in green coffee to get rid of it. Cimetidine (Tagamet) can decrease how quickly your body breaks down caffeine. Taking cimetidine (Tagamet) along with green coffee might increase the chance of caffeine side effects including jitteriness, headache, fast heartbeat, and others.
- Fluconazole (Diflucan)
- The body breaks down the caffeine in green coffee to get rid of it. Fluconazole (Diflucan) might decrease how quickly the body gets rid of caffeine. Taking fluconazole (Diflucan) and green coffee might increase the effects and side effects of coffee including nervousness, anxiety, and insomnia.
- Medications for diabetes (Antidiabetes drugs)
- Caffeine in green coffee might increase blood sugar. Diabetes medications are used to lower blood sugar. By increasing blood sugar, green coffee might decrease the effectiveness of diabetes medications. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.
Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.
- Medications for high blood pressure (Antihypertensive drugs)
- Green coffee might decrease blood pressure. Taking green coffee along with medications for high blood pressure might cause your blood pressure to go too low.
Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), Amlodipine (Norvasc), hydrochlorothiazide (HydroDIURIL), furosemide (Lasix), and many others.
- Mexiletine (Mexitil)
- Green coffee contains caffeine. The body breaks down caffeine to get rid of it. Mexiletine (Mexitil) can decrease how quickly the body breaks down caffeine. Taking Mexiletine (Mexitil) along with green coffee might increase the caffeine effects and side effects of coffee.
- Terbinafine (Lamisil)
- The body breaks down the caffeine in green coffee to get rid of it. Terbinafine (Lamisil) can decrease how fast the body gets rid of caffeine and increase the risk of side effects including jitteriness, headache, increased heartbeat, and other effects.
Are there interactions with herbs and supplements?
- Bitter orange
- Bitter orange in combination with caffeine or caffeine-containing herbs can increase blood pressure and heart rate in otherwise healthy adults with normal blood pressure. This might increase the risk of developing serious heart problems. Avoid this combination.
- Caffeine-containing herbs and supplements
- Using green coffee along with other caffeine-containing herbs and supplements increases exposure to caffeine and increases the risk of developing caffeine-related side effects. Other natural medicines that contain caffeine include black tea, cocoa, cola nut, green tea, oolong tea, guarana, and mate.
- High caffeine intake from foods and beverages including green coffee increases the amount of calcium that is flushed out in the urine.
- The dietary fiber cyclodextrin has been shown to complex with certain components of green coffee that are responsible for its blood pressure-lowering effects. Theoretically, consuming cyclodextrin and green coffee may reduce the absorption of this component and reduce its beneficial effects on blood pressure.
- Ephedra (Ma huang)
- Green coffee contains caffeine, which is a stimulant. Using green coffee with ephedra, which is also a stimulant, might increase the risk of experiencing serious or life-threatening side effects such as high blood pressure, heart attack, stroke, seizures, and death. Avoid taking coffee with ephedra and other stimulants.
- Herbs and supplements that might lower blood pressure
- Green coffee decreases blood pressure. When used with other herbs and supplements that reduce blood pressure, green coffee may have additive blood pressure-lowering effects. Other natural medicines with blood pressure-lowering effects include alpha-linolenic acid, blond psyllium, calcium, cocoa, cod liver oil, coenzyme Q-10, garlic, olives, potassium, pycnogenol, sweet orange, vitamin C, wheat bran, and others.
- Herbs and supplements that might lower blood sugar
- Green coffee extract can lower blood glucose levels. Using it with other herbs or supplements that have the same effect might cause blood sugar levels to drop too low. Some herbs and supplements that can lower blood sugar include alpha-lipoic acid, chromium, devil's claw, fenugreek, garlic, guar gum, horse chestnut, Panax ginseng, psyllium, Siberian ginseng, and others.
- Herbs and supplements that slow blood clotting
- The caffeine in green coffee might slow blood clotting. Taking green coffee and using herbs that might also slow blood clotting could increase the risk of bleeding in some people. Some of these herbs include angelica, clove, danshen, garlic, ginger, ginkgo, Panax ginseng, and others.
- Certain components of green coffee may prevent iron from being absorbed from food. Theoretically, this may result in levels of iron in the body becoming too low.
- Taking large amounts of green coffee can increase the amount of magnesium that is flushed out in the urine.
Are there interactions with foods?
- There are no known interactions with foods.
What dose is used?
To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.
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