What is caffeic acid?

Caffeic acid (3,4-dihydroxy-cinnamic acid) is an organic compound and a potent antioxidant. It can be found naturally in a wide range of plants.

Caffeic acid is a type of polyphenol, a class of micronutrients known for their antioxidant properties. The nutrient is claimed to have many health benefits, including anti-inflammatory, anticancer, and antiviral abilities. It may help boost the performance of athletes. However, it isn’t considered “essential” for human health. In other words, you don’t need it to survive.

The most common source of caffeic acid in the human diet is from drinking coffee. It’s also found in certain vegetables, fruits, and herbs. Some examples of foods containing caffeic acid include:

  • coffee
  • wine
  • turmeric
  • basil
  • thyme
  • oregano
  • sage
  • cabbage
  • apples
  • strawberries
  • cauliflower
  • radishes
  • mushrooms
  • kale
  • pears
  • olive oil

Despite its name, caffeic acid is unrelated to caffeine.

Caffeic acid is a known antioxidant. Antioxidants help prevent the oxidation of other molecules in the body. Oxidation produces free radicals, which can damage cells. This in turn can lead to inflammation, heart disease, or even cancer.

Caffeic acid is also claimed to:

  • reduce inflammation
  • prevent cancer
  • prevent toxicity associated with chemotherapy and radiation
  • prevent diabetes
  • prevent premature aging
  • prevent neurodegenerative diseases, like Parkinson’s disease
  • reduce exercise-related fatigue

Like other antioxidants, caffeic acid may be helpful in improving overall health as we age. Its antioxidant properties may help reduce chances of developing cancer, heart disease, and other illnesses of old age, like Alzheimer’s disease. In addition, it may keep skin looking younger by protecting it from damage from the sun.

The best way to get caffeic acid is from food. If you eat a diet rich in fruits and vegetables, or you drink coffee on a regular basis, you’re probably getting a fair amount of caffeic acid in your diet already.

Caffeic acid is also marketed as a supplement:

  • to boost athletic performance
  • to aid in weight loss
  • to treat certain viruses, including herpes and HIV
  • as part of a cancer treatment regimen
  • in skin care serums

However, more evidence is needed to support these uses and to determine the proper dosage needed to produce the most benefits.

Most studies showing the health benefits of caffeic acid have been done in mice or rats. Studies in humans are limited and most have been done in vitro, meaning outside of the body using cells in a petri dish or test tube.

More research is needed to assess how caffeic acid is absorbed in the human body. A small study in seven people found that over 90 percent of caffeic acid ingested was absorbed by the small intestine.

Boosting athletic performance

A small study was performed to see if caffeic acid could help competitive athletes during prolonged periods of endurance exercise. The study used caffeic acid phenethyl ester (CAPE), a caffeic acid derivative.

After extracting cells from the blood of competitive cyclists, some of the cells were treated with CAPE, while others were not. Then all of the cells were subjected to hyperthermal (heat) stress. The researchers found that cells treated with CAPE were better able to handle and recover from the stress. More research is needed to replicate these findings outside of the laboratory.

Another study found that caffeic acid improved exercise tolerance and reduced markers of fatigue associated with exercise in rats.

Preventing diabetes

One study found that caffeic acid was able to significantly reduce blood sugar levels in mice with diabetes compared to a control group. More research in humans is needed.

Reducing cancer risk

Research on coffee has shown a link between regular consumption of coffee and incidence of certain types of cancer compared to people who don’t drink coffee. Studies have suggested that daily coffee intake, including decaffeinated coffee, is associated with a reduced incidence of colon and rectal cancer. Researchers think that these effects are attributed to polyphenol compounds, like caffeic acid.


Due to its antioxidant and anti-inflammatory properties, caffeic acid is often found in skin care regimens. Studies show promising results. A study in mice, for example, found that caffeic acid from garlic applied topically to the skin of mice successfully prevented wrinkle formation induced by UVB irradiation. It also inhibited oxidative stress. The authors concluded that caffeic acid shows potential as an active ingredient for skin treatments against UVB-induced skin damage.

Enhancing cancer treatment

Many drugs used to treat cancer, such as chemotherapy and radiation, can result in unintended damage to organs, including the kidneys and liver. Several studies performed in rats or using extracted human cells have shown promise in using caffeic acid derivatives to help reduce the toxicity associated with certain cancer treatments. This may lead to better outcomes.

Treating HIV

Caffeic acid and its derivatives have been shown to inhibit the virus known as HIV. While researchers don’t propose using caffeic acid alone to treat HIV, they suggest that including more caffeic acid-rich foods in the diet could help improve overall treatment for the infection. More research is needed to confirm these benefits.

There is little information available about the safety and side effects of caffeic acid. Caffeic acid supplements haven’t been studied extensively in humans. So far, no serious side effects have been reported.

Keep in mind that natural products and supplements aren’t subjected to rigid safety and efficacy requirements by the U.S. Food and Drug Administration. Make sure to read the label for dosing instructions. If you have concerns, consult your doctor or a pharmacist before taking a supplement.

Since there isn’t enough evidence to show whether caffeic acid supplements are safe for pregnant or breastfeeding women, it should be avoided.

Caffeic acid is naturally found in plants, including coffee, and may be just another reason why a plant-based diet, including coffee, is good for you. While most studies have been done in rats or mice, caffeic acid has been shown to be a powerful antioxidant and anti-inflammatory. It may also be useful as part of a treatment regimen for cancer, HIV, or diabetes, but more research in humans is needed to confirm these effects.

You can get caffeic acid and other antioxidants from a dietary supplement. However, the compounds are also widely available in many common fruits and vegetables, on top of your morning coffee. If you’re looking for an antioxidant boost, it’s important to eat a wide variety of fruits and vegetables and avoid excessive alcohol, smoking, air pollutants, and processed meats. Ask your doctor before using caffeic acid to treat diabetes, cancer, HIV, or other illnesses.