Oregano (Origanum vulgare) is an herb from the mint family native to Europe, Asia, and the Mediterranean. It is commonly used to add flavor to Italian and Mexican dishes.
Oil of oregano, also known as oregano oil or oregano extract, is extracted from various parts of the oregano plant. It is said to have antioxidant, antibacterial, and anti-inflammatory properties that may treat infection, improve gut health, and more.
Here are the potential benefits, uses, risks, and side effects of oil of oregano.
Oil of Oregano vs. Oregano Essential Oil
Although the two terms are often used interchangeably, oil of oregano and oregano essential oil are two different products. Oil of oregano, widely available in pill or capsule form, is made by extracting beneficial compounds from the plant using alcohol or carbon dioxide.
Oregano essential oil, on the other hand, is extracted from the plant's leaves, stems, or flowers using steam distillation. Unlike oil of oregano, it is not safe to consume orally. It should only be mixed with a carrier oil and applied to the skin or diffused.
Whether applied topically or consumed orally, oregano oil shows potential to treat various ailments, especially bacterial infections.
However, it is important to note that most research has been conducted in test tubes or animals. We cannot say for sure that these benefits will apply to humans.
Here's a closer look at the potential benefits of oil of oregano.
Rich in Antioxidants
Oregano, in both fresh and dry form, has potent antioxidant properties. Antioxidants are substances that may stabilize free radicals, preventing them from causing cell damage in the body.
Oregano oil is particularly rich in the antioxidants carvacrol, thymol, and octacosanol, which appear to be responsible for most of the herb's health benefits.
One study done in a test tube found that treating cells with oregano extract before exposing them to hydrogen peroxide counteracted the oxidative stress caused by hydrogen peroxide.
Oxidative stress is a condition that occurs when there are too many unstable free radicals in the body and not enough antioxidants to get rid of them. Prolonged oxidative stress can lead to aging and chronic inflammation.
What Are Free Radicals?
Free radicals are highly reactive chemicals created when an atom loses or gains an electron. They are formed naturally in the body and play a key role in several cellular processes. However, at high concentrations, free radicals can damage DNA in cells, potentially leading to cancer and other chronic diseases.
May Help Reduce Inflammation
Both oil of oregano and oregano essential oil have been shown to have anti-inflammatory properties.
One study in rats found that topical application of oregano extract significantly reduced inflammation caused by Propionibacterium acnes, a bacteria that can cause skin inflammation and acne.
Another study found that carvacrol—oregano's main antioxidant—reduced inflammation and blood cholesterol levels in mice fed a high-fat diet.
Additionally, a study in human skin cells found that oregano essential oil may help fight inflammation, promote wound healing, boost the immune system, and even protect against cancer.
However, it is important to note that oregano essential oil may have a toxic effect on some cells. Human studies are needed before it can be routinely recommended to calm inflammation.
Antibacterial Properties
With its high carvacrolcontent, oregano oil shows promise for treating bacterial infections when applied topically.
One 2021 study found oregano oil showed significant anti-bacterial activity against 11 types of bacteria that are resistant to multiple antibiotics.
Other studies suggest that oregano essential oil may have protective effects against several types of bacteria, including those associated with food poisoning and dental cavities.
However, due to safety and toxicity concerns, oregano essential oil should not be consumed orally unless recommended by a healthcare provider.
May Help Improve Respiratory Function
Oregano has long been used in traditional medicine to treat respiratory conditions, including asthma, cough, and bronchitis.
Two randomized control trials found that carvacrol supplements improved inflammation, lung function, and respiratory symptoms in patients with lung damage and asthma.
Still, further research is necessary to determine whether oil of oregano will produce these same effects.
May Improve Digestive Health
Oil of oregano was traditionally used to treat digestive problems like indigestion, diarrhea, and upset stomach.
While human research is limited, there is some evidence that oil of oregano may prevent or kill the growth of harmful bacteria in the gut.
One observational study found that herbal preparations, including one containing oregano, may be as effective as antibiotics in treating small intestine bacterial overgrowth (SIBO).
SIBO is a relatively common condition that causes abdominal pain, gas, bloating, and diarrhea due to an overabundance of bacteria growing in the small intestine.
Oregano's gut health benefits are believed to be due to its carvacrol and thymol content, which exert anti-inflammatory, anti-bacterial, and anti-oxidative properties.
Anti-Fungal Properties
Oregano may help fight fungal infections.
A 2022 test-tube study found that oregano essential oil was effective against Candida albicans, a type of yeast (fungus).
When candida grows out of control, it may cause thrush and yeast infections. In severe cases, it may cause infections in the bloodstream, heart, brain, or kidneys.
An overgrowth of candida may worsen inflammatory bowel diseases like Crohn's disease and ulcerative colitis.
In addition, a 2020 study in 20 patients showed that a topical antifungal containing oregano improved nail fungus. However, the antifungal had several other compounds, making it difficult to determine whether oregano oil alone would produce these same results.
How to Use Oil of Oregano
The oregano plant is a woody, perennialplant with dark green, oval leaves that are slightly fuzzy. Most supplements are made using the plant's leaves and stems.
Oil of oregano supplements are widely available in capsules, soft gels, and liquid tinctures designed to be taken orally.
Most manufacturers recommend taking oregano oil with meals to minimize potential side effects and enhance absorption.
Oregano essential oils are also available for purchase. They should be diluted with a carrier oil before being applied to the skin. Essential oils, including oregano essential oil, are highly concentrated and should not be consumed orally.
Dosage
Due to a lack of human research, there is no specific recommended dosage for oil of oregano.
However, most oil of oregano supplements have dosage recommendations on the label provided by the manufacturer. These recommendations are typically based on the concentration of beneficial compounds like carvacrol and thymol.
Oil of oregano supplements vary greatly from brand to brand. Always follow the manufacturer's instructions and dosing recommendations.
Consult your healthcare provider for further dosing guidance.
Over-the-counter (OTC) oregano oil extracts are generally recognized as safe (GRAS).
Oregano may cause allergic reactions in some people. Avoid it if you're allergic to any other plants in the Lamiaceae family, like basil, mint, and sage.
Oregano supplements should also be avoided if you're pregnant or breastfeeding. Consuming oregano in larger amounts than commonly found in food may cause miscarriage.
Due to limited research, children should avoid oil of oregano unless otherwise recommended by their pediatrician.
High amounts of oregano may increase the risk of bleeding. People who take large amounts of oregano extract should stop taking it two weeks before surgery.
There isn't enough research to determine the safety of oregano essential oil when applied to the skin or taken by mouth.
Potential Drug Interactions
Oil of oregano may interact with the following prescription medications and supplements:
- Blood thinners: Oregano may increase the risk of bleeding and bruising in people taking blood thinners.
- Diabetes medications: Oregano may lower blood sugar levels. Taking it with diabetes medications may cause blood sugar to drop too low.
- Copper, iron, and zinc supplements: Oregano may decrease the absorption of copper, iron, and zinc in the body. Most manufacturers recommend taking oregano two hours before or after these supplements.
- Herbs that may slow blood clotting: Oregano may increase the risk of bleeding when combined with garlic, ginger, ginkgo, and other supplements that slow blood clotting.
- Herbs that may lower blood sugar: Oregano may cause blood sugar to drop too low when combined with bitter melon, chromium, aloe, and other supplements that decrease blood sugar.
There is no evidence suggesting that oregano interacts with any other foods.
What to Look For
Like all supplements, oil of oregano is not evaluated by the Food and Drug Administration (FDA) for safety before being sold.
This makes it important to purchase your supplement from a transparent brand that utilizes third-party testing to ensure label accuracy and purity. Reputable third-party testing organizations include NSF, ConsumerLab, and USP.
While not as potent as oregano extract, fresh oregano leaves are considered safe to consume in moderate amounts. This is as long as they come from plants you've grown or another trusted source.
Consuming oregano in the wild is generally not recommended, as there is a chance that it may be confused with potentially harmful plants.
Can You Take Too Much Oil of Oregano?
There is no established upper limit for oregano oil. However, taking more than the manufacturer recommends can increase the risk of side effects and safety concerns.
Side Effects of Oil of Oregano
Oil of oregano is generally well-tolerated. However, taking high amounts may lead to negative effects, including:
- Abdominal pain
- Heartburn
- Constipation
- Diarrhea
- Nausea
- Vomiting
- Headache
- Dizziness
Oregano essential oil may cause skin irritation when topically applied in concentrations greater than 1%.
Oil of oregano has antioxidant, anti-inflammatory, and anti-fungal properties that may make it beneficial for infections, gut health, and immunity. Yet, human research supporting these benefits is limited.
While oil of oregano is generally well-tolerated with a good safety profile, oregano essential oil is much stronger and may not be safe.
If you are considering taking oil of oregano, talk with your healthcare provider to determine whether it may be beneficial and safe for you.
