Green Coffee

The botanical name of green coffee is Coffea arabica or Coffea canephora. Green coffee refers to the unroasted seeds of these plants, which naturally contain higher levels of chlorogenic acid than roasted coffee. Roasting develops the characteristic flavour, aroma and colour of coffee but reduces the amount of this plant compound, which is why green coffee is marketed separately.

Green coffee comes from the seeds inside the fruit of the coffee plant, commonly known as the coffee cherry. Two species supply almost all commercial coffee: Coffea arabica and Coffea canephora, better known as Robusta. After harvesting, the pulp is removed and the seeds are dried, graded and packed without roasting. The plant is native to the highlands of Ethiopia and is believed to have reached southern India in the seventeenth century. Today it is grown mainly in Karnataka, Kerala and Tamil Nadu.

Green coffee is not described in the classical Ayurvedic texts, including the Charaka Samhita, Sushruta Samhita and Ashtanga Hridaya, as coffee reached India centuries later. Any Ayurvedic classification (Rasa, Virya, Vipaka or Dosha action) assigned to green coffee today is based on modern interpretation rather than classical Ayurvedic literature.

Green coffee is known by a few descriptive names. As a modern product rather than a classical Ayurvedic herb, it does not have widely recognised traditional names in most Indian languages.

• Botanical Names: Coffea arabica L., Coffea canephora Pierre ex A. Froehner
• English: Green coffee, green coffee bean, raw coffee, unroasted coffee bean
• Hindi: Hari coffee, Kaccha coffee
• Tamil: Kaapi (coffee)
• Malayalam: Kaapi (coffee)
• Kannada: Kaapi (coffee)
• Arabic: Bunn (coffee bean), Qahwa (coffee)

The compounds below are naturally present in the unroasted coffee bean. Several of them are reduced or altered once the bean is roasted, which contributes to the chemical differences between green coffee and roasted coffee.

• Chlorogenic acids, chiefly 5-caffeoylquinic acid. These are the compounds for which green coffee is most commonly marketed, and their levels are substantially reduced by roasting.
• Caffeine, the stimulant alkaloid. It is present in the raw bean and is not created by roasting.
• Trigonelline, an alkaloid that is partially converted into niacin when the bean is heated.
• Caffeic acid, ferulic acid and p-coumaric acid, related plant phenolic acids.
• Quinic acid, which contributes to the characteristic taste of the brew.
• Diterpenes, mainly cafestol and kahweol, found in the coffee bean oil.
• Tannins, a group of astringent plant compounds.
• Proteins, polysaccharides and lipids, which make up most of the physical bulk of the bean.

The constituent list for green coffee bean extract is described in (Sudeep & Shyam Prasad, 2021). The proportions vary considerably with species, growing region, altitude and drying methods, so two green coffee products can differ considerably in their composition and chlorogenic acid content.

The actions below are based on laboratory and clinical research. They describe the potential effects of green coffee and should not be considered treatment claims.

• Antioxidant: may help neutralise free radicals and reduce oxidative stress.
• Mild central nervous system stimulant: caffeine may increase wakefulness and reduce feelings of fatigue.
• Possible glucose-modulating action: limited human studies suggest it may help influence glucose metabolism or slow carbohydrate absorption, although the evidence remains limited.
• Possible lipid-modulating action: Experimental studies have examined possible effects on lipid metabolism, but these findings have not established a clinically meaningful benefit.
• Mild diuretic action: caffeine may increase urine output.
• Anti-inflammatory activity: laboratory studies suggest chlorogenic acid may help reduce some inflammatory markers.

Most of these properties come from laboratory and animal research or from limited human trials of concentrated extracts. They describe the direction in which green coffee appears to act, not established clinical benefits, and should not be used as a basis for replacing prescribed treatment.

The health benefits below are based on limited research. Green coffee is not a substitute for medical treatment.

May Support Weight Management Alongside Diet and Exercise

Chlorogenic acids may slow glucose absorption in the gut and influence how the liver handles fat. Pooled trial data suggest a small reduction in body mass index, though changes in body weight and waist circumference were not statistically significant (Gorji et al., 2019). Any effect appears to be modest and depends on diet and physical activity.

Provides Antioxidant Activity

Chlorogenic acids act as antioxidants, they help the body neutralise reactive molecules called free radicals. Roasting reduces much of this compound, so unroasted beans retain more of it. Laboratory studies support this antioxidant activity, but a measurable long-term health benefit in people has not yet been demonstrated.

May Slow the Rise in Blood Glucose After a Meal

Small human studies suggest chlorogenic acid may slow how quickly glucose passes from the gut into the blood after eating (Thom, 2007). This was seen in a very small group of healthy volunteers. It is not a treatment for high blood sugar and should not replace prescribed medicines.

Contains Caffeine, Which May Aid Alertness

Green coffee contains caffeine, a mild stimulant that blocks adenosine, a brain chemical involved in promoting sleepiness. As a result, some people may notice a modest improvement in alertness and concentration. The amount of caffeine varies widely between products and preparations.

May Support Normal Blood Vessel Function

Some small human trials have suggested that chlorogenic acid may support the endothelium, the inner lining of blood vessels that helps them relax normally (Roshan et al., 2018). Findings are inconsistent and short-term. This is not a treatment for high blood pressure or any diagnosed heart condition.

Studied in Skincare for Its Antioxidant Content

Antioxidant compounds from green coffee have been studied in skincare for their effect on oxidative stress in skin cells. Most of this evidence comes from laboratory studies or topical skincare products. Drinking green coffee has not been shown to reduce wrinkles or slow visible aging.

Green coffee is commonly used for the purposes described below. These are common uses and should not be considered proven clinical benefits.

As a Daily Drink in Place of Roasted Coffee

Some people brew green coffee instead of ordinary coffee because it contains higher levels of chlorogenic acids than roasted coffee. The taste is mild, grassy and closer to a weak herbal tea than to a roasted brew.

Within a Structured Weight Management Programme

Standardised extracts are most often taken as capsules or tablets over a fixed course of about 8 to 12 weeks, alongside a calorie-controlled diet and regular physical activity, rather than on their own. Evidence for this use in humans remains limited.

Before Study or Desk Work, as a Caffeine Source

A brewed cup is sometimes taken in the morning or early afternoon as a source of caffeine. It is not suitable late in the day, because caffeine can delay sleep for several hours.

In Cosmetic and Skincare Products

Green coffee oil and extract appear in creams, serums and scrubs. Applying these products to the skin is different from consuming green coffee, and results from one do not carry over to the other.

Blended Into Combination Supplements

Green coffee extract is frequently sold mixed with other plant extracts in weight-management products. These blends may also contain additional sources of caffeine or other active ingredients, making the total caffeine intake harder to judge, so the label should always be read in full.

Green coffee contains caffeine, so it has many of the same precautions as regular coffee. Concentrated extracts may contain higher amounts of active compounds, so read the safety information before use.

• Children and adolescents: Green coffee supplements are not recommended for children and adolescents. Caffeine can affect sleep, mood and appetite in young people, and no safe supplement dose has been established for this group.
• Pregnancy and breastfeeding: Avoid green coffee supplements during pregnancy and breastfeeding. There is not enough safety evidence on concentrated extracts, and caffeine crosses the placenta and passes into breast milk.
• Heart conditions: Speak to your doctor first if you have high blood pressure, an irregular heartbeat or any heart condition, because caffeine can increase heart rate and blood pressure.
• Diabetes: Consult your doctor first if you have diabetes or take medicines to lower blood sugar. Green coffee may affect blood glucose levels, and your readings may need closer monitoring.
• Digestive conditions: If you have acid reflux, a peptic ulcer, irritable bowel syndrome (IBS) or frequent loose stools, consult your doctor before using green coffee, as it may aggravate these conditions.
• Liver disease: If you have liver disease or a history of liver problems, consult your doctor before using green coffee or any weight-management supplement.
• Anxiety or sleep problems: Use green coffee with caution if you have anxiety, panic attacks or difficulty sleeping, as caffeine may worsen these symptoms.
• Bone health: If you have osteoporosis or low bone density, use green coffee with caution, as high caffeine intake may increase calcium loss.
• Before surgery: Stop using green coffee supplements at least two weeks before planned surgery and tell your surgical team, as caffeine can affect blood pressure and heart rhythm.
• Glaucoma: If you have glaucoma, consult your doctor before using green coffee, as caffeine may temporarily increase pressure inside the eye.
• Total caffeine intake: Count all your caffeine, not just the green coffee. Tea, cola, energy drinks, chocolate and ordinary coffee all add to your daily total.
• Product quality: Buy supplements from a licensed seller and check the label for the chlorogenic acid content and whether the product is decaffeinated. Supplement strength is not tightly regulated and varies widely between brands.

Note: Stop taking green coffee and seek medical advice if you develop a fast or irregular heartbeat, chest pain, severe headache, yellowing of the skin or eyes, dark urine, persistent nausea or unusual tiredness. Herbal and weight-loss supplements are an established cause of liver injury and should not be continued if these symptoms appear (NIDDK, 2025).

Green coffee is available as beans, powder, capsules and extracts. Use each product according to the manufacturer's instructions.

Brewing Whole Green Coffee Beans

Rinse one to two tablespoons of beans, then soak them in about 200 ml of water overnight. In the morning, bring the water and beans to a gentle simmer for around 15 minutes, then strain out the beans and drink the liquid warm. The beans are too hard to grind at home before soaking.

Preparing Ground Green Coffee Powder

Stir half to one teaspoon of powder into a cup of hot, but not boiling, water. Leave it to stand for five to ten minutes, then strain if you prefer a clear drink. Adding lemon or a small amount of honey may make the grassy taste more palatable.

Taking Capsules or Tablets

Swallow with a full glass of water, with or shortly after food, following the dose printed on the pack. Do not open a capsule or crush a tablet unless the label says you may. Avoid taking more than one green coffee supplement at the same time unless advised by a healthcare professional.

Using a Standardised Liquid Extract

Measure the dose with the dropper or cap supplied, never with a kitchen spoon, and dilute it in water or juice. Liquid extracts are concentrated, so even a small measuring error can result in a significant difference in the amount taken.

Choosing a Product Safely

Choose a product that clearly states the chlorogenic acid content, caffeine per serving, batch number and expiry date. Buy only from a licensed pharmacy or reputable seller, and avoid products that make unrealistic weight-loss claims.

Ingredients Commonly Combined With Green Coffee

Green coffee is often combined with other herbal extracts in weight-management products. These are modern formulations rather than classic Ayurvedic combinations. Check the product label carefully, as blends may contain additional stimulants or other active ingredients.

Note: Do not combine several weight-management supplements at once. Each adds its own risks, and the more products taken together, the harder it becomes to identify the cause if something goes wrong.

Green coffee is a supplement, not a medicine with an approved dose, and products differ widely in strength. The guidance below is general. Ask a doctor or a qualified Ayurvedic practitioner what is right for you before starting.

Children Under 12 Years

Green coffee is not recommended in any form. Caffeine-containing supplements are not suitable for young children.

Teenagers Aged 12 to 17 Years

Green coffee supplements are not recommended for this age group. Where caffeine is consumed from ordinary food and drink, a daily intake of up to 3 mg per kilogram of body weight is considered not to raise safety concerns (EFSA NDA Panel, 2015). For a 50 kg teenager that is about 150 mg from all sources combined.

Adults Aged 18 to 64 Years

Standardised extracts have been studied at doses of approximately 200 mg to 800 mg daily, usually split into two doses and taken for 8 to 12 weeks (Gorji et al., 2019). Evidence for long-term use remains limited. As a brewed drink, one to two cups a day is typical. Keep total caffeine from every source below 400 mg a day (EFSA NDA Panel, 2015).

Older Adults Aged 65 and Above

Start at the lowest dose recommended by the manufacturer and review it with a doctor first. Caffeine may be metabolised more slowly with age, and older adults are more likely to be taking medicines that interact with it.

During Pregnancy and Breastfeeding

Avoid green coffee supplements altogether. If you drink caffeinated beverages, keep total caffeine below 200 mg a day during pregnancy (EFSA NDA Panel, 2015).

Do not exceed the dose printed on the product label, and do not take more than one green coffee product at the same time.

Most side effects are related to the caffeine in green coffee and are more likely at higher doses or in people who are sensitive to it. The list below highlights common and important side effects.

Headache

Caffeine can trigger headaches in people who are sensitive to it, and stopping caffeine suddenly after regular use can also cause withdrawal headaches. Reducing the dose gradually rather than all at once usually helps.

Faster or Irregular Heartbeat

Caffeine can raise the heart rate and, in some people, cause a fluttering or pounding sensation in the chest. Anyone with a known heart rhythm problem should avoid green coffee unless advised otherwise by their doctor.

Restlessness and Shakiness

Restlessness, nervousness or mild hand tremor may indicate excessive caffeine. It usually settles within a few hours as the caffeine wears off.

Anxiety and Mood Changes

Caffeine can worsen existing anxiety and, at higher intakes, cause irritability or changes in mood. People with an anxiety disorder often notice this at doses others tolerate easily.

Difficulty Sleeping

Caffeine stays active in the body for several hours, so a dose taken late in the day can delay sleep and reduce its quality. Taking green coffee before mid-afternoon may help reduce this risk.

Digestive Upset

Loose stools, stomach cramps, nausea and acid reflux have been reported. Taking the dose with food rather than on an empty stomach may help reduce these effects.

Short-Term Rise in Blood Pressure

Caffeine can temporarily increase blood pressure for a few hours after a dose. This matters most for people who already have high blood pressure or who are monitoring it at home.

Reduced Absorption of Iron and Calcium

Compounds in coffee can reduce how much iron the body absorbs from plant foods, and a high caffeine intake may increase calcium excretion in the urine. Leaving a gap of one to two hours between green coffee and meals or supplements may help minimise this effect.

Rare Liver Injury

Weight-loss and herbal supplements have been associated with drug-induced liver injury, and green coffee has appeared among the products involved in reported cases (NIDDK, 2025). This is uncommon but serious.

When to Stop and Seek Medical Help

Stop taking green coffee and contact a doctor straight away if you develop chest pain, a persistently fast or irregular heartbeat, breathlessness, severe or persistent headache, yellowing of the skin or eyes, dark urine, pain in the upper right side of the abdomen, or unusual tiredness that does not settle.

Green coffee can affect how some medicines work, mostly because of its caffeine. Tell your doctor or pharmacist that you are taking it, particularly in the situations below.

Other Sources of Caffeine and Stimulants

Coffee, tea, cola, energy drinks and stimulant supplements all add to your daily caffeine intake. Combining them may increase the risk of a racing heart, restlessness and disturbed sleep.

Certain Antibiotics

Ciprofloxacin and related fluoroquinolone antibiotics may slow the breakdown of caffeine, so its effects may last longer and feel stronger. Consider reducing your caffeine intake while taking these medicines.

Fluvoxamine and Some Other Antidepressants

Fluvoxamine can significantly slow caffeine clearance and may markedly increase its effects. Discuss any caffeine supplement with your doctor if you take it.

Theophylline and Similar Respiratory Medicines

Theophylline works in a similar way to caffeine. Taking both together increases the chance of a fast heartbeat, tremor, nausea and restlessness.

Blood Pressure Medicines

Caffeine can temporarily increase blood pressure for a few hours and may reduce the effectiveness of these medicines in some people. Home readings taken soon after consuming caffeine can also be misleading.

Diabetes Medicines and Insulin

Green coffee may alter blood glucose levels. If you take medicines to lower blood sugar, check your readings more closely and speak to your doctor before starting.

Levothyroxine and Bisphosphonates

Coffee may reduce the absorption of these medicines. Leave at least 30 to 60 minutes between taking the tablet and drinking any coffee, including green coffee.

Iron Supplements

Plant compounds in coffee may reduce iron absorption. Leave a gap of one to two hours between an iron tablet and green coffee.

Blood Thinning and Antiplatelet Medicines

Ask your doctor before combining these with green coffee, as evidence on potential interactions is limited, and the potential risk of bleeding should be assessed individually.

Storage of Green Coffee

Green coffee should be stored properly to help preserve its chlorogenic acid content and overall quality. The guidance below covers each form.

• Store whole beans and powder in an airtight container in a cool, dry place away from heat, sunlight, and moisture.
• Do not refrigerate, as condensation can introduce moisture and encourage mould growth.
• Use ground green coffee within the shelf life stated on the product label.
• Keep capsules and tablets in their original packaging until use.
• Store liquid extracts tightly closed and follow the storage instructions on the label.
• Keep all products out of the reach of children.
• Do not use the product if it has an unusual smell, is discoloured or has passed its expiry date.

• Green coffee is the unroasted bean of the coffee plant. Because it has not been roasted, it retains more chlorogenic acid than roasted coffee.
• It contains caffeine. Roasting does not create caffeine, so green coffee is not automatically a low-caffeine option, and the amount varies from product to product.
• Evidence for weight management benefits in humans remains limited. Pooled trial data suggest a small change in body mass index but no significant change in body weight or waist circumference, and much of the early publicity was based on a study that was later retracted.
• It is not a treatment for any diagnosed condition, including diabetes, high blood pressure or heart disease, and should never replace prescribed medicines.
• Common side effects include headache, a faster heartbeat, restlessness, disturbed sleep and digestive upset, which are mainly caused by caffeine.
• It is not recommended for children, adolescents, or people who are pregnant or breastfeeding.
• Speak to a doctor first if you take any regular medicine, or if you have a heart, liver, blood pressure or blood sugar condition.