Green coffee is increasingly common in the health and wellness community.

As such, you may have heard about its rich supply of health-promoting plant compounds.

This article takes an in-depth look at green coffee, including its potential benefits and risks.

What is green coffee?

Green coffee beans are simply regular coffee beans that haven’t been roasted and remain completely raw.

Their extract is popular as a dietary supplement, but green coffee can also be purchased in whole-bean form and used to make a hot beverage, much like roasted coffee.

Bear in mind that a mug of this light green drink will not taste like the roasted coffee you’re used to, as it has a much milder flavor. It’s said to taste more like herbal tea than coffee.

What’s more, its chemical profile is quite different than that of roasted coffee, though their origins are similar.

It boasts an abundant supply of chlorogenic acids — compounds with potent antioxidant and anti-inflammatory effects that may provide many health benefits (1).

Roasted coffee products also contain small amounts of chlorogenic acid, but most of it is lost during the roasting process (2).

Green coffee beans are raw, unroasted coffee beans. They contain high levels of a group of antioxidants known as chlorogenic acids, which are thought to provide numerous benefits.

Does it work as a weight loss supplement?

In 2012, green coffee extract was promoted as a miracle weight loss supplement by American celebrity physician and talk-show host Dr. Oz.

Many health experts have since refuted the notion that it has any significant impact on weight.

Even so, green coffee extract remains one of the most popular weight loss supplements on the market.

Several small studies have treated mice with the extract and found that it reduced total body weight and fat accumulation significantly. However, studies in humans have been far less conclusive (3, 4).

Most human research on green coffee has been inconclusive. While some participants lost weight, the studies were poorly designed with small sample sizes and short durations (5).

Thus, no definitive evidence demonstrates that green coffee is effective for weight loss. Larger, well-designed human studies are needed.

Green coffee is marketed as a weight loss aid, but scientific evidence supporting its effectiveness is lacking. More human research is needed.

May reduce your risk of some chronic diseases

Green coffee may have health benefits other than weight loss.

In fact, its chlorogenic acids may help reduce your risk for chronic diseases like diabetes and heart disease (6).

In an 8-week study, 50 people with metabolic syndrome — a cluster of risk factors, including high blood pressure and blood sugar, that increase your risk for diabetes and heart disease — took 400 mg of decaffeinated green coffee bean extract twice daily (7).

Those who took the extract experienced significant improvements in fasting blood sugar, blood pressure, and waist circumference, compared with a control group.

Although these results are promising, larger studies are needed.

Green coffee may reduce your risk for heart disease and type 2 diabetes, though more research is needed.

Possible risks and side effects

Green coffee is largely safe but may have several potential risks (5).

Effects of excess caffeine

Much like roasted coffee, green coffee beans naturally contain caffeine.

Although moderate caffeine intake is likely safe for most healthy people, too much could lead to negative symptoms, such as anxiety, sleep disturbances, and increased blood pressure (8).

One cup (8 ounces) of either black or green coffee provides roughly 100 mg of caffeine, depending on the variety and brewing method (8).

Because a small amount of caffeine may be lost during the roasting process, green coffee may contain slightly more caffeine than black — but the difference is likely negligible (2).

Meanwhile, green coffee supplements usually offer 20–50 mg per capsule, though some are decaffeinated during processing.

If you’re taking green coffee in any form, you may want to moderate your intake to avoid effects.

May affect bone health

A 2-month animal study found that mice given daily doses of green coffee extract experienced significant calcium depletion in their bone tissue (9).

These results suggest that long-term intake of green coffee supplements may harm bone health.

That said, human research is needed.

Overconsumption of caffeine in green coffee could cause negative symptoms. Furthermore, early research in animals suggests it may harm bone health, though human studies are necessary.

Suggested dosage

Insufficient data exists on green coffee to establish clear dosing recommendations.

That said, at least one study used doses of up to 400 mg of green coffee extract twice daily, reporting no negative effects (7).

If you’re considering taking this extract, consult your healthcare provider to ensure that you’re taking a safe amount.

No clear dosing recommendation has been established for green coffee, but some studies have safely used doses of up to 400 mg of the extract twice per day.

The bottom line

Green coffee refers to the raw beans of the coffee plant.

Its extract was popularized as a weight loss supplement, and it may promote healthy blood sugar and blood pressure levels, though research on its effectiveness is limited.

Few adverse effects have been reported, but its caffeine content may cause side effects.

If you’re considering adding green coffee to your routine, consult your healthcare provider to make sure it’s safe for you.

You can also use the whole beans to make a hot beverage.

If you’re interested in trying green coffee or its extract, you can shop for it locally or find whole beans and supplements online.