What is Chlorogenic Acid?
Chlorogenic acid is a polyphenol compound found in coffee beans and different types of coffee, including green coffee. It is also found in food sources such as apples, pears, eggplant, blueberries, tomatoes, strawberries, and potatoes [1, 2, 3, 4, 5].
Chlorogenic acid is most commonly supplemented in the form of green coffee extract.
It has a variety of effects on health and is most notably used to reduce blood pressure and weight loss. However, recent studies have indicated that chlorogenic acid may improve mood, reduce oxidative stress, and lower blood sugar levels .
Note: Many studies refer to chlorogenic acids (plural) as opposed to chlorogenic acid. The plural form refers to a related family of molecules called polyphenol esters and is not exclusively referring to the effects of the individual esterified molecule, chlorogenic acid.
Natural Sources (or Forms of Supplementation)
Green coffee bean extract is the primary natural source of chlorogenic acid and is taken in a supplemental form .
Chlorogenic acid is also a component of coffee and many fruits and vegetables, including apples, pears, eggplant, blueberries, tomatoes, strawberries, and potatoes. It is also found in bamboo, hawthorn, and Athrixia phylicoides [1, 2, 3, 4, 5].
Mechanism of Action
Chlorogenic acid primarily exerts its effects by inhibiting the enzyme alpha-glucosidase, which is responsible for breaking down carbohydrates. Therefore, it reduces the uptake of carbohydrates and glucose during digestion [8, 9].
Chlorogenic acid may also work by:
- Inhibiting 11-βHSD1, an enzyme involved in making hormones that raises blood pressure 
- Activating the GABAa receptor by binding to the benzodiazepine site, resulting in reduced levels of anxiety 
- Increasing Glucagon-like peptide 1 (GLP-1), a hormone that increases blood insulin levels and lowers glucose .
- Activating Peroxisome Proliferator-Activated Receptor alpha (PPAR-alpha), leading to increased heat production and body fat loss .
- Lowering body fat content by reducing levels of triglycerides, LDL–cholesterol, and VLDL 
- Preventing the absorption of fats, the production of fats (inhibition of fatty acid synthase), and increasing beta-oxidation, leading to the breakdown of fats .
- Inhibiting HMG-CoA, the enzyme responsible for the production of cholesterol and the main target of statin drugs 
- Improving the survival of dopaminergic neurons through the inhibition of microglial activation 
- Inhibiting acetylcholinesterase, resulting in improved cognition and memory 
Health Benefits of Chlorogenic Acid
1) Chlorogenic Acid Lowers Blood Pressure
In 117 men with high blood pressure (DB-PCT), green coffee bean extract (rich in chlorogenic acid) for 28 days lowered blood pressure .
Similarly, in 37 humans with stage 1 hypertension (SB-RCT), green coffee bean extract rich in chlorogenic acid reduced blood pressure and improved blood vessel dilation (postprandial endothelial dysfunction) .
In 28 hypertensive humans (DB-RCT), isolated chlorogenic acid reduced blood pressure .
In 20 humans with elevated blood pressure, green coffee bean extract for 4 months also lowered blood pressure. This effect is suggested to be caused by the presence of chlorogenic acid .
A single dose of chlorogenic acid (30 to 600 mg) reduced blood pressure in hypertensive rats. It also improved the structure of blood vessels (endothelial function) .
2) Chlorogenic Acid Is Anti-Diabetic and Anti-Obesity
In 16 obese individuals (DB-PCT), green coffee bean extract for 22 weeks reduced weight, BMI, and body fat percentage .
Chlorogenic acid helped with glucose and fat metabolism, which relieved the effects of late diabetes in mice .
Mice given 5 mg/kg of chlorogenic acid exhibited anti-diabetic effects .
3) Chlorogenic Acid May Improve Mood
In 39 elderly humans (DB-RCT), 3 cups of decaffeinated coffee enriched with chlorogenic acid improved mood and attention [R].
In mice treated with E. ulmoides extract enriched with chlorogenic acid, 7 days of treatment reduced depression-like symptoms (tail suspension test). In rat neurons, chlorogenic acid treatment (from E. ulmoides) protected cell growth, structure, and increased serotonin release .
4) Chlorogenic Acid Is Antimicrobial
In a study of 45 individuals with Streptococcus mutans infection (DB-RCT), gargling twice daily for 2 weeks using a green coffee bean extract mouthwash reduced the number of bacteria .
In mice with Staphylococcus aureus infection, chlorogenic acid prevented the harmful effects of the bacteria and reduced bacterial number. This was caused by the inhibition of the bacterial enzyme sortase A .
Chlorogenic acid exerted antibacterial effects in cells by disrupting the bacterial membranes, leading to cell death .
5) Chlorogenic Acid May Reduce Cancer Growth
Topical application of chlorogenic acid prevented skin tumor growth in mice .
In a mouse model of colon cancer, supplementing chlorogenic acid in the diet reduced the toxic effects (carcinogenicity) of certain chemicals and decreased tumor growth .
In lung cancer cells, chlorogenic acid-induced cell death (apoptosis) and prevented cell growth .
In cells, combining chlorogenic acid with the chemotherapy drug 5-fluorouracil increased cell death through the production of reactive oxygen species (ROS) and deactivation of cancer-inducing proteins (ERK1/2) .
6) Chlorogenic Acid Relieves Oxidative and Inflammatory Stress
The antioxidant activity may be attributed to the upregulation of antioxidant proteins such as glutathione and vitamins C and E. Additionally, chlorogenic acid reduced levels of oxidative proteins and reactive oxygen species that induce oxidative stress [44, 27, 45].
Cell studies show chlorogenic acid may decrease cell death (apoptosis), reduce DNA fragmentation, and lower levels of reactive oxygen and nitrogen species (ROS/RNOS) .
7) Chlorogenic Acid Has Neuroprotective Effects
Chlorogenic acid can improve brain function and neurodegenerative disorders. In mice, chlorogenic acid improved short-term and working memory and reversed cognitive impairments by inhibiting acetylcholinesterase .
In a mouse model of Alzheimer’s disease, chlorogenic acid improved the spatial and working memory of the mice (Morris water maze). Cell studies indicated a neuroprotective effect against beta-amyloid proteins – the main cause of Alzheimer’s disease .
Animal studies indicated chlorogenic acid improved the survival of neurons containing dopamine. This suggests a potential benefit for patients with neurodegenerative conditions such as Parkinson’s disease .
Chlorogenic acid prevented the toxic effects of alpha-synuclein, the protein implicated in the destruction of dopamine-containing neurons and the development of Parkinson’s disease .
Allergies to green coffee bean extract, the natural source of chlorogenic acid, have been reported. Symptoms were primarily asthma attacks. However, this does not seem to be due to the chlorogenic acid itself [49, 50].
Limitations and Caveats
Most of the studies conducted examined the effects of green coffee bean extracts, which contains a number of active molecules. Therefore, it cannot be concluded that chlorogenic acid is responsible for the results seen. Further studies on the effects of isolated chlorogenic acid should be undertaken to conclusively determine its effects.
Importantly, the majority of studies were conducted in mice, so further testing in humans is needed. Although side effects have rarely been reported, many of the studies conducted were the very short term. Long-term testing is needed to assess the possible side effects.
Furthermore, a number of studies, particularly on green coffee bean extract, were sponsored by companies that profit from the sales of green coffee bean extract. The results are not necessarily invalid, but caution must be used when evaluating industry-funded research.
Chlorogenic acid works against metformin, a medication used to treat high blood sugar levels. However, this only occurs in high concentrations of chlorogenic acid, so this is unlikely to have an effect in humans .
Consult your doctor if you are taking metformin or any other medications before supplementing with chlorogenic acid.
Use caution when using green coffee bean later in the evening, for the high caffeine content may cause trouble sleeping.
Different manufacturers produce green coffee bean supplements that may have more or less chlorogenic acid. The user-recommended dose for chlorogenic acid ranges from 240 mg to 3,000 mg per day, depending on the specific supplement.
Users wishing to obtain the effects of chlorogenic acid supplement with green coffee bean extract, as it is the main source of this compound.
Mild weight loss has also been reported by users, as well as an increase in energy. Some users reported no effect after taking green coffee bean supplements.