Drink it in a latte. Pour it over ice. Taste it in tiramisu. Blend it into a green smoothie? Coffee in a smoothie may sound odd, but green coffee bean extract makes it possible. It's showing up in energy drinks, pre-workouts and supplements, often with big promises attached. Here's what green coffee bean actually is, what the research shows, and where the hype gets ahead of the evidence.
What is green coffee bean?
Quick question: what color is a coffee bean? If you said brown, here's the twist. Before roasting, coffee beans are green.
Roasting creates the flavor, aroma and color of the coffee we drink, and it also changes the bean's chemistry. Coffee beans are especially rich in antioxidant compounds called chlorogenic acids, and roasting transforms a share of them into other compounds. Green coffee extract keeps more of the original chlorogenic acids, and a study in healthy adults found these are well absorbed and metabolized by the body.
Green coffee beans also contain caffeine. How much ends up in an extract depends on how it's made, so always check the label rather than assuming it's a low-caffeine option.
Does green coffee bean extract help with weight loss?
This is green coffee's claim to fame, and it deserves a careful look.
A 2012 trial that made green coffee extract famous on television was later retracted, so it shouldn't be relied on. The better evidence comes from reviews of many trials:
- A 2011 meta-analysis of three trials found an average weight loss of about 2.5 kg compared with placebo, but noted that all of the studies were of poor methodological quality.
- A larger 2021 meta-analysis of 15 studies and 637 participants found an average weight loss of about 1.2 kg, along with small improvements in cholesterol, fasting blood sugar and blood pressure.
So green coffee extract may have a modest effect, but it's no shortcut. Diet, activity and sleep still do the heavy lifting.
Caffeine plays a part too. In a classic study, 100 mg of caffeine raised resting metabolic rate by 3 to 4%, and repeated doses through the day increased energy expenditure by 8 to 11%, about 150 extra calories a day in lean volunteers.
Does green coffee affect blood sugar and heart health markers?
In the 2021 meta-analysis, green coffee extract was associated with small average reductions in total cholesterol (about 6 mg/dL), fasting blood sugar (about 2 mg/dL) and systolic blood pressure (about 3 mmHg). Those are modest changes in mostly short studies, and green coffee is not a substitute for medical care. If you're managing blood sugar, cholesterol or blood pressure, talk to your doctor before adding a supplement.
Does green coffee improve energy and focus?
Yes, mainly because of its caffeine. Research reviews find that caffeine improves alertness, attention and reaction time, and that it can enhance physical performance. The International Society of Sports Nutrition concludes that caffeine improves many kinds of exercise performance at 3 to 6 mg per kilogram of body weight. That's why green coffee extract is a popular caffeine source in pre-workouts.
Our Renewable Energy pre-workout includes organic green coffee bean, alongside organic matcha and yerba mate, for 90mg of caffeine, paired with beetroot, pomegranate and an adaptogen blend of ashwagandha, rhodiola, ginseng and maca. If you want a stronger dose, Renewable Energy Plus gets all of its 180mg of caffeine from organic green coffee beans. Both are designed for a clean energy boost before a workout or a busy day.
Is green coffee bean extract safe?
For most healthy adults, green coffee is about as safe as the caffeine it contains. Add up your sources: the FDA cites 400 mg a day as an amount not generally associated with negative effects. During pregnancy, ACOG advises keeping caffeine under 200 mg a day. If you're sensitive to caffeine, have a heart condition or take medication, check with your doctor first.
Want to compare caffeine sources? Read about matcha, yerba mate and how much coffee you should be drinking.
