Oregano Oil: Is It Good for You?

Medically Reviewed by Zilpah Sheikh, MD on December 03, 2023
Written by Shawna Seed
6 min read

Oregano oil, or oil of oregano, comes from the leaves of the oregano plant and has been used in folk medicine for centuries to prevent illness. Today, many people still use it to fight infections and the common cold despite its renowned bitter, unpleasant taste.

Although more research is needed into the health benefits of oregano oil, studies have confirmed that it has the following properties:

  • Antimicrobial
  • Antiviral
  • Antifungal
  • Antioxidant
  • Anti-inflammatory 
  • Antidiabetic

One teaspoon of dried oregano leaves contains: 

  • Calories: 2.65
  • Protein: 0.09 gram
  • Fat: 0.04 gram
  • Carbohydrates: 0.69 gram
  • Fiber: 0.42 gram
  • Sugar: 0.04 gram

Oregano is a good source of iron.

I t's also an excellent source of vitamin K. Studies have shown that vitamin K is important for bone health and regulating blood sugar.

Oregano oil also contains antioxidants, which help stop free radicals from causing damage to your cells that can lead to serious diseases such as cancer.

Research has found a number of potential health benefits of oregano oil: 

Antibacterial properties

Several studies have shown the powerful antibacterial properties of oregano oil, even against antibiotic-resistant strains of bacteria.

In one study that tested the antibacterial effects of a range of essential oils, oregano oil was found to be the best at hindering bacterial growth.

Because it can protect against bacterial infection, topical oregano oil has been shown to be effective in wound treatment and healing.

Oregano oil contains a substance called carvacrol, which studies have found to be effective against a bacteria called Staphylococcus aureus. That bug can contaminate food, especially meat and dairy products, and is a leading cause of foodborne illness around the world. 

Researchers also have found that the herbal oil can effective in treating small intestinal bacterial overgrowth (SIBO), a digestive condition. 

Antioxidant properties

Another substance found in oregano oil is thymol. Both it and carvacrol have antioxidant effects and may be able to replace synthetic antioxidants added to foods.

Anti-Inflammatory effects

Oregano oil also has anti-inflammatory effects. One study showed that oregano essential oil significantly inhibited several inflammatory biomarkers in skin. 

Improvement of acne

Because of its combined antibacterial and anti-inflammatoryproperties, oregano oil may help improve the appearance of acne by reducing blemishes. Because using oral antibiotics to treat acne has a range of potential side effects, oregano oil may provide a safe and effective alternative when used topically.

Cholesterol management

Oregano oil has been found to support healthy cholesterol levels. A study of 48 people who took a small amount of oregano oil after each meal showed a significant reduction in their LDL (or “bad”) cholesterol, which is one of the main causes of the clogged arteries that can lead to heart disease.

Digestive health

Oil of oregano is commonly used to treat digestive problems like belly cramps, bloating, and irritable bowel syndrome, among others. While more research continues, experts have found that carvacrol is effective against types of bacteria that cause digestive discomfort.

Oregano oil for yeast infections

Yeast infections, caused by a fungus called candida, are one of the most common types of vaginal infections. Some strains of candida are becoming resistant to antifungal drugs. Early research on oregano oil in vapor form as an alternative is promising. 

Fights fungal infections

Vaginal yeast infections aren't the only fungus that oregano oil can fight. Thymol works against toenail fungus, for instance.

Oregano oil and colds

One small study found that people with upper respiratory viruses who used a spray that contained oregano oil and other herbal ingredients felt better 20 minutes later. In lab tests, carvacrol interfered with some human and animal viruses.

Oregano oil and cancer

Scientists are looking at whether the compounds in oregano oil can help fight cancer. So far, the research isn't conclusive. Some studies have shown that oregano oil reduced the size of tumors in animals. Experiments on human cancer cells in lab settings showed that oregano oil might slow their growth.

Because oregano oil has such potent ingredients, you should consult with your doctor before taking it or any other supplement. Consider the following before using oregano oil either internally or topically:

Toxicity

Because oregano oil is such a powerful antimicrobial agent, it can be toxic to humans. Taken in large doses, it can be deadly. Only use the recommended amount of oregano to yield its benefits.

Skin irritation

Although oregano oil can help with some skin ailments, like acne, it may irritate sensitive skin. Don’t apply undiluted oregano oil directly to your skin. Patch test any products containing oregano oil to ensure they won’t cause any negative effects. Additional research on skin irritation caused by it on humans is required.

Pregnancy concerns

Research on the effects of oregano oil on someone who is pregnant or breastfeeding has been inconclusive. If you’re pregnant or breastfeeding a baby, it's best to look for an alternative. 

Medication interference

Avoid oregano oil if you’re taking a diuretic because it may worsen medication side effects. Oregano has natural diuretic properties, and it may interfere with the action of lithium and similar medications. 

Surgery risks

Because oregano can interfere with your blood clotting, you should stop taking it 2 weeks before any scheduled surgery.

Oil of oregano can be purchased at just about any grocery or health food store. It’s also common for people to make it at home by blending oregano leaves with olive oil or another oil of your choice. 

To prepare your own oil of oregano at home, follow these steps:

  1. Wash and chop your oregano leaves.
  2. Place them in a clear jar, then add warmed oil and stir.
  3. Seal the jar and keep it in a cool, dark place for up to 2 weeks, giving the jar a shake every day or so. 
  4. After 2 weeks, strain the oil and discard the leaves. Seal and refrigerate the now-infused oil of oregano and use it as desired. 

The FDA says oregano oil is "generally recognized as safe" as a food product. But unlike drugs, dietary supplements don't have to go through as many tests before they are allowed on the market in the U.S. Read labels carefully and follow the recommended oregano oil dose on the packaging. Be aware that the label might not accurately reflect what's in the product. 

Oregano oil can be added to food, but it may upset your stomach if you take large amounts. If you're using it on your skin, avoid anything stronger than 1 percent concentration. 

It's important to understand the difference between oregano oil and oregano essential oil. Essential oils are highly concentrated versions usually sold for aromatherapy. They're not meant for you to use them without diluting them. If you don't know the strength of the oil, you can't assume that swallowing it or putting it directly on your skin is safe.

If you're allergic to basil, hyssop, lavender, marjoram, mint, or sage, you might also be allergic to oregano. They're from the same plant family.

Oregano oil has been used in folk medicine for centuries. Studies have shown that it can fight bacteria and fungal infections and has antioxidant properties. You can find it in health food stores or make your own at home. It can be dangerous in large quantities, and it can irritate your skin, so talk to your doctor before you add oregano oil to your health care routine. 

What does oregano oil do for you?

Oregano oil has many uses. It fights bacteria and fungus, so it can work on skin infections and acne. Some people take it for colds. It may work to lower cholesterol levels. You may take it for digestive health, but taking too much can cause stomach upset. 

Is oregano oil safe to take daily?

There's not enough reliable information on what amount of oregano oil is a safe dose.