Background

Green coffee is unroasted coffee beans from Coffea fruits (Coffea arabica, Coffea canephora). It contains more chlorogenic acid than roasted coffee.

The chlorogenic acid in green coffee is thought to have health benefits. It might affect blood vessels so that blood pressure is reduced. It might also affect how the body handles blood sugar and metabolism. Green coffee also contains caffeine, but in lower amounts than regular coffee.

People take green coffee for obesity, diabetes, high blood pressure, high cholesterol, and many other conditions, but there is no good scientific evidence to support these uses.

Don't confuse green coffee with other caffeine sources, including coffee, black tea, and green tea. These are not the same.

Safety Safety definitions

When taken by mouth: Green coffee is possibly safe when used appropriately. Green coffee extracts taken in doses up to 1000 mg daily have been used safely for up to 12 weeks. A specific green coffee extract (Svetol, Naturex) has been used safely in doses up to 200 mg five times daily for up to 12 weeks.

Green coffee contains caffeine, but in lower amounts than in regular coffee. One cup of green coffee contains about 25-50% of the amount of caffeine found in a one cup of regular coffee. Consuming large amounts of green coffee might cause caffeine-related side effects, including headache, anxiety, agitation, and irregular heartbeat.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if green coffee is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.

Abnormally high levels of homocysteine: Consuming a high dose of chlorogenic acid might increase homocysteine levels, which might be linked to conditions such as heart disease.

Anxiety disorders: The caffeine in green coffee might make anxiety worse.

Bleeding disorders: The caffeine in green coffee might make bleeding disorders worse.

Diabetes: The caffeine in green coffee might affect the way people with diabetes process sugar. Use caffeine with caution if you have diabetes and monitor your blood sugar carefully.

Diarrhea: Green coffee contains caffeine. Caffeine, especially when taken in large amounts, can worsen diarrhea.

Epilepsy: Green coffee contains caffeine. People with epilepsy should avoid using caffeine in high doses. Low doses of caffeine should be used cautiously.

Glaucoma: The caffeine in green coffee can increase pressure inside the eye, which can make glaucoma worse.

High blood pressure: The caffeine in green coffee might increase blood pressure in people with high blood pressure. But this effect might be less in people who consume caffeine regularly.

Irritable bowel syndrome (IBS): Green coffee contains caffeine. Caffeine, especially when taken in large amounts, might worsen the diarrhea some people have with IBS.

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.

Effectiveness

Dosing & administration

Green coffee extract has most often been used by adults in doses of 90-1000 mg by mouth daily for 8-12 weeks. Speak with a healthcare provider to find out what dose might be best for a specific condition.

Keep in mind that green coffee contains caffeine, but in lower amounts than in regular coffee. When coffee beans are roasted, they release water and the caffeine in the bean is more readily released when brewed. Unroasted (green) coffee beans release less caffeine when brewed. One cup of green coffee contains about 20-50 mg of caffeine, compared to about 100 mg in one cup of regular coffee.

Interactions with pharmaceuticals

Adenosine (Adenocard)

Interaction Rating=Moderate Be cautious with this combination.

Green coffee contains caffeine. The caffeine in green coffee might block the effects of adenosine, which is often used by doctors to do a test called a cardiac stress test. Stop consuming green coffee at least 24 hours before a cardiac stress test.

Alcohol (Ethanol)

Interaction Rating=Minor Be watchful with this combination.

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 increase the risk for caffeine side effects including jitteriness, headache, and fast heartbeat.

Alendronate (Fosamax)

Interaction Rating=Moderate Be cautious with this combination.

Green coffee might decrease how much alendronate the body absorbs. Taking green coffee and alendronate at the same time might decrease the effects of alendronate. Don't take green coffee within two hours of taking alendronate.

Antibiotics (Quinolone antibiotics)

Interaction Rating=Minor Be watchful with this combination.

The body breaks down caffeine 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 caffeine side effects including jitteriness, headache, increased heart rate, and others.

Birth control pills (Contraceptive drugs)

Interaction Rating=Moderate Be cautious with this combination.

Green coffee contains caffeine. The body breaks down caffeine to get rid of it. Birth control pills can decrease how quickly the body breaks down caffeine. This might increase the risk for side effects from caffeine, such as jitteriness, headache, and fast heartbeat.

Cimetidine (Tagamet)

Interaction Rating=Moderate Be cautious with this combination.

The body breaks down the caffeine in green coffee to get rid of it. Cimetidine can decrease how quickly your body breaks down caffeine. Taking cimetidine along with green coffee might increase the chance of caffeine side effects including jitteriness, headache, fast heartbeat, and others.

Clozapine (Clozaril)

Interaction Rating=Moderate Be cautious with this combination.

The body breaks down clozapine to get rid of it. The caffeine in green coffee might decrease how fast the body breaks down clozapine. Taking green coffee along with clozapine can increase the effects and side effects of clozapine.

Dipyridamole (Persantine)

Interaction Rating=Moderate Be cautious with this combination.

The caffeine in green coffee might block the effects of dipyridamole. Dipyridamole is often used by doctors to do a test on the heart called a cardiac stress test. Stop taking green coffee at least 24 hours before a cardiac stress test.

Disulfiram (Antabuse)

Interaction Rating=Moderate Be cautious with this combination.

The body breaks down the caffeine in green coffee to get rid of it. Disulfiram can decrease how quickly the body gets rid of caffeine. Taking green coffee along with disulfiram might increase the side effects of caffeine including jitteriness, hyperactivity, irritability, and others.

Ephedrine

Interaction Rating=Major Do not take this combination.

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.

Estrogens

Interaction Rating=Moderate Be cautious with this combination.

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 and green coffee might increase caffeine side effects, including jitteriness, headache, fast heartbeat, and others. If you take estrogen, limit your caffeine intake.

Fluconazole (Diflucan)

Interaction Rating=Minor Be watchful with this combination.

The body breaks down the caffeine in green coffee to get rid of it. Fluconazole might decrease how quickly the body gets rid of caffeine. Taking fluconazole and green coffee might increase caffeine side effects including nervousness, anxiety, and insomnia.

Fluvoxamine (Luvox)

Interaction Rating=Moderate Be cautious with this combination.

The body breaks down the caffeine in green coffee to get rid of it. Fluvoxamine can decrease how quickly the body breaks down caffeine. Taking caffeine along with fluvoxamine might increase caffeine side effects including nervousness, anxiety, and insomnia.

Lithium

Interaction Rating=Moderate Be cautious with this combination.

Green coffee contains caffeine. Caffeine can increase how quickly your body gets rid of lithium. If you take products that contain caffeine and you take lithium, don't stop taking caffeine products all at once. Instead, reduce use slowly. Stopping caffeine too quickly can increase the side effects of lithium.

Medications for asthma (Beta-adrenergic agonists)

Interaction Rating=Moderate Be cautious with this combination.

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.

Medications for depression (MAOIs)

Interaction Rating=Moderate Be cautious with this combination.

Green coffee contains caffeine. There is some concern that caffeine can interact with certain medications, called MAOIs. If caffeine is taken with these medications, it might increase the risk of serious side effects including fast heartbeat and very high blood pressure.

Some common MAOIs include phenelzine (Nardil), selegiline (Zelapar), and tranylcypromine (Parnate).

Medications for diabetes (Antidiabetes drugs)

Interaction Rating=Minor Be watchful with this combination.

Green coffee might increase or decrease blood sugar levels. Taking green coffee along with diabetes medications might change the effects of these medications. Monitor your blood sugar closely.

Medications for high blood pressure (Antihypertensive drugs)

Interaction Rating=Minor Be watchful with this combination.

Green coffee might lower blood pressure. Taking green coffee along with medications that lower blood pressure might cause blood pressure to go too low. Monitor your blood pressure closely.

Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)

Interaction Rating=Moderate Be cautious with this combination.

Green coffee might slow blood clotting. Taking green coffee along with medications that also slow blood clotting might increase the risk of bruising and bleeding.

Mexiletine (Mexitil)

Interaction Rating=Minor Be watchful with this combination.

Green coffee contains caffeine. The body breaks down caffeine to get rid of it. Mexiletine can decrease how quickly the body breaks down caffeine. Taking mexiletine along with green coffee might increase the risk of caffeine side effects.

Nicotine

Interaction Rating=Moderate Be cautious with this combination.

Green coffee contains caffeine. Taking caffeine along with nicotine might increase rapid heart rate and blood pressure.

Pentobarbital (Nembutal)

Interaction Rating=Moderate Be cautious with this combination.

Green coffee contains caffeine. The stimulant effects of caffeine can block the sleep-producing effects of pentobarbital.

Phenothiazines

Interaction Rating=Minor Be watchful with this combination.

Green coffee contains caffeine. The body breaks down caffeine to get rid of it. Phenothiazines can decrease how quickly the body breaks down caffeine. Taking phenothiazines along with green coffee might increase the risk of caffeine side effects.

Phenylpropanolamine

Interaction Rating=Moderate Be cautious with this combination.

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.

Pioglitazone (Actos)

Interaction Rating=Moderate Be cautious with this combination.

Green coffee contains caffeine. Caffeine might increase the amount of pioglitazone that the body absorbs. Taking green coffee might increase the effects and adverse effects of pioglitazone.

Riluzole (Rilutek)

Interaction Rating=Moderate Be cautious with this combination.

Green coffee can decrease how quickly the body breaks down riluzole and increase the effects and side effects of riluzole.

Stimulant drugs

Interaction Rating=Moderate Be cautious with this combination.

Stimulants, such as amphetamines and cocaine, speed up the nervous system. By speeding up the nervous system, stimulant medications can increase blood pressure and speed up the heartbeat. Green coffee contains caffeine. Caffeine 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.

Terbinafine (Lamisil)

Interaction Rating=Minor Be watchful with this combination.

The body breaks down the caffeine in green coffee to get rid of it. Terbinafine can decrease how fast the body gets rid of caffeine. This might increase the risk of caffeine side effects including jitteriness, headache, increased heartbeat, and others.

Theophylline

Interaction Rating=Moderate Be cautious with this combination.

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, others)

Interaction Rating=Moderate Be cautious with this combination.

Verapamil can decrease how quickly the body gets rid of caffeine. Drinking green coffee and taking verapamil can increase the risk of caffeine side effects including jitteriness, headache, and an increased heartbeat.

Water pills (Diuretic drugs)

Interaction Rating=Moderate Be cautious with this combination.

The caffeine in green coffee can reduce potassium levels. "Water pills" can also decrease potassium levels in the body. Taking caffeine with water pills might cause potassium levels to drop too low.
Some "water pills" that can deplete potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), hydrochlorothiazide (HCTZ, HydroDiuril, Microzide), and others.

Interactions with herbs & supplements

Bitter orange: Green coffee contains caffeine. Bitter orange, used along with caffeine or caffeine-containing herbs such as green coffee, can increase blood pressure and heart rate in otherwise healthy people. This might damage the heart and blood vessels.
Caffeine-containing herbs and supplements: Green coffee contains caffeine. Taking it along with other products that contain caffeine might increase caffeine side effects. Examples of supplements that contain caffeine include black tea, coffee, green tea, guarana, and yerba mate.
Calcium: Green coffee contains caffeine. High doses of caffeine can increase the loss of calcium in the urine.
Cordyceps: Green coffee contains caffeine. Cordyceps might increase how quickly the body gets rid of caffeine. This might decrease the effects of caffeine.
Creatine: Green coffee contains caffeine. There is some concern that combining caffeine or caffeine-containing beverages and herbs with ephedra and creatine might increase the risk of serious side effects. There is a report of stroke in one athlete who used creatine monohydrate, caffeine, ephedra, and a variety of other supplements daily for 6 weeks. Caffeine might also decrease creatine's possible beneficial effects on athletic performance.
Cyclodextrin: Cyclodextrin is a dietary fiber. It might bind with a chemical found in green coffee, called chlorogenic acid. This might reduce the blood pressure-lowering effects of green coffee.
Echinacea: Green coffee contains caffeine. The body breaks down caffeine to get rid of it. Echinacea might decrease how quickly the body breaks down caffeine. Using echinacea with caffeine might increase caffeine levels.
Ephedra (Ma huang): Don't take green coffee with ephedra. Using ephedra with the caffeine in green coffee might increase the risk of serious life-threatening or disabling conditions such as hypertension, heart attack, stroke, seizures, and death.
Genistein-containing herbs and supplements: Green coffee contains caffeine. The body breaks down caffeine to get rid of it. Taking herbs or supplements that contain genistein might decrease how quickly the body breaks down caffeine. Using genistein with caffeine might increase caffeine levels.
Herbs and supplements that might lower blood pressure: Green coffee might lower blood pressure. Taking it with other supplements that have the same effect might cause blood pressure to drop too much. Examples of supplements with this effect include andrographis, casein peptides, L-arginine, niacin, and stinging nettle.
Herbs and supplements that might lower blood sugar: Green coffee might lower blood sugar. Taking it with other supplements with similar effects might lower blood sugar too much. Examples of supplements with this effect include aloe, bitter melon, cassia cinnamon, chromium, and prickly pear cactus.
Herbs and supplements that might slow blood clotting: Green coffee might slow blood clotting and increase the risk of bleeding. Taking it with other supplements with similar effects might increase the risk of bleeding in some people. Examples of supplements with this effect include garlic, ginger, ginkgo, nattokinase, and Panax ginseng.
Iron: Certain components of green coffee might reduce the amount of iron the body absorbs from food.
Kudzu: Green coffee contains caffeine. The body breaks down caffeine to get rid of it. Kudzu seems to decrease how quickly the body breaks down caffeine. Using kudzu with caffeine might increase caffeine levels.
Magnesium: Green coffee contains caffeine. High doses of caffeine can increase how quickly the body releases magnesium in the urine.
Melatonin: Green coffee contains caffeine. Taking caffeine and melatonin together can increase melatonin levels.

Interactions with foods

There are no known interactions with foods.