Oregano Oil: What the Science Says About 8 Possible Benefits and Risks

You’re probably familiar with oregano as a popular topping on spaghetti, lasagna, and pizza. But outside its use as an herb, its oil has been thought to have many health benefits.

But are these claims actually rooted in evidence? Let’s take a closer look.

What is oregano oil?

Oregano (Origanum vulgare) is a plant with olive-green leaves and purple flowers. The oil it contains is called oregano oil. This is extracted and sold as an over-the-counter (OTC) supplement in pill, capsule, or liquid form. You may see oregano oil supplements labeled as:

• Oil of oregano

• Oregano leaf

• Oregano extract

Liquid oregano oil supplements usually contain alcohol and water or a carrier oil, like olive oil. 

The idea that oregano oil might offer benefits against different health conditions comes from its antioxidant content and their link to boosting the body’s natural defense system. Here are three oregano oil compounds:

• Carvacrol: As the most abundant compound in oregano, carvacrol has shown potential to fight off certain bacteria in lab experiments.

• Rosmarinic acid: This powerful antioxidant has been linked to lower inflammation in lab experiments.

• Thymol: Like carvacrol, thymol might offer protection against certain viruses and other toxins in lab experiments.

Oregano oil vs. oregano essential oil

Oregano oil that you take by mouth is not the same as oregano essential oil. Essential oils are highly concentrated and inhaled as part of aromatherapy. They can also be applied topically (on the skin), by mixing a few drops of essential oil with a carrier oil.

Directions on diluting oregano essential oil vary by brand. But studies that have looked at applying it to the skin generally use 1%, or around 3 drops of oregano essential oil for every tablespoon of carrier oil. A concentration higher than 1% can irritate the skin.

Because of how concentrated essential oils are, don’t take them by mouth unless a healthcare professional recommends it. Some oils can cause serious health effects.

EXPERT PICKS: WHAT TO READ NEXT

• Lavender oil benefits: This essential oil may have several health benefits, including promoting relaxation. Learn about other possible uses.

• Essential oils for sore muscles: Looking for a natural way to soothe achy muscles? Learn more about arnica, ginger, and other oils.

• Essential oils and eczema: Check out the popular essential oils that people use for this skin condition, and which ones to avoid.

What are the health benefits of oregano oil?

Oregano oil is often marketed as a natural remedy for various health conditions, including:

• Cold and flu

• Digestive issues

• Skin problems

• Inflammation

But there’s a lack of quality research on the effectiveness and safety of oregano oil for humans. Most findings come from lab studies. So let’s take a closer look at what the science shows about oregano oil’s reported benefits.

Read more like this

Explore these related articles, suggested for readers like you.

The Top 10 Essential Oils to Soothe Sore, Painful Muscles

Does Rosemary Oil Help With Hair Growth?

Are Essential Oils Good for Eczema? A Look at 5 of the Most Popular Ones

The 3 Best and Worst Oils for Cooking

View more

1. May improve digestive health

It’s possible — but more studies in people are needed to fully understand its effects.

Some evidence shows that oregano oil may have antifungal properties. A recent study found that oregano oil was effective against Candida albicans, a type of yeast that can lead to infections in different parts of the body, including the mouth.

2. May have an antibacterial effect on skin

Oregano oil might help with different skin issues. Some research showed oregano oil to be effective against Staphylococcus aureus, a bacteria that can cause skin infections. But the concentrations used were very high.

For example, according to one study, antibacterial effects were seen with a concentration of 12.5% to 25%. Because of skin irritation, it wouldn’t be possible to use oregano essential oil at this high of a concentration.

A review of studies suggests that oregano oil’s anti-inflammatory activity might help with acne, skin concerns related to aging, and wound healing.

3. May lower inflammation

The evidence is mixed on oregano oil’s effectiveness at decreasing inflammation. Research in the lab has shown that carvacrol in oregano oil may help lower inflammation by stopping the production of inflammatory molecules in the body.

As a result, scientists are studying whether this finding can translate to benefits like:

• Anti-cancer benefits

• Diabetes prevention

• Immune protection

But another review that looked at 17 studies found oregano oil to only be effective against certain inflammation markers.

4. May lower cholesterol and help prevent diabetes

Animal studies have shown that a compound in oregano oil was able to help lower cholesterol in mice. Rats that were fed the oregano oil compound were also found to have lower glucose and higher insulin levels. This led researchers to believe that oregano oil could help protect against diabetes too. 

Keep in mind that nobody has done any studies in humans yet. So it’s still too early to say if oregano oil can play a role in cholesterol and diabetes management in people.

5. May help with pain management

Some research shows that oregano oil compounds might be able to help with pain control. Studies have shown that rodents that ingested a compound found in oregano oil had lower rates of cancer pain as well as oral and facial pain. 

Again, these studies were performed on animals and have yet to be replicated in humans. So the results don’t mean that oregano oil will necessarily work for your pain management. 

6. May help with weight loss

There’s optimism that oregano oil may be able to help with obesity and weight loss. Animal studies have shown that mice given an oregano oil compound showed fewer signs of excess weight. Cellular studies also showed that an oregano oil compound can actually block fat cells from building up. These studies are promising and point to oregano oil possibly being used to help with weight loss in the future. 

7. May have anti-cancer activity

Research on human colon cancer cells showed that oregano oil compound has anti-tumor properties. Researchers found that oregano oil compound helped kill off tumor cells and stop their growth. Studies on prostate cancer cells had similar results. 

There’s no evidence that oregano oil can actually help fight cancer in people today. But these studies suggest that it might provide some protection at the cellular level. 

8. May help fight yeast infections

A study of several different essential oils — including cinnamon, juniper, and thyme — found that oregano oil had some of the best antifungal properties. When introduced to a sample of yeast cells, oregano oil was found to stop yeast growth. This study was done in petri dishes, so it’s a long way away from human studies. The idea is that scientists may find a way to use oregano oil in the future to help fight yeast infections. 

What are the side effects and risks of oregano oil?

The reported side effects are generally mild. When taken by mouth, the most common ones are upset stomach and diarrhea.

But there are certain risks that can affect some people:

• Allergies: Applying oregano oil topically can lead to skin irritation or an allergic reaction — especially if you’re sensitive or allergic to related herbs, like mint, basil, and sage.

• Certain medications: Taking oregano oil as a supplement may raise the risk of bleeding and lead to low blood sugar levels. So, if you take diabetes medication or blood thinners, avoid oregano oil.

• Pregnancy: Oregano oil is also not recommended for people who’re pregnant or nursing.

Always talk with a healthcare professional before starting a new supplement. They can confirm whether it’s safe for you to try. As with any natural remedy, it’s important to know about possible risks and side effects.

How do you use oregano oil to support your health?

Much more evidence is needed before any benefits can be confirmed. But oregano oil is still a popular supplement sold as a pill or liquid.

Consider the following tips if you choose to try oregano oil:

• Speak to your healthcare professional first.

• Look for an oregano oil supplement verified by the United States Pharmacopeia (USP) or National Sanitation Foundation (NSF). This means the product has gone through extra testing for purity.

• If you opt for liquid oregano oil, read the label to make sure it’s combined with a carrier oil, like olive oil. Don’t take oregano essential oil by mouth.

• Follow the package instructions when starting a new product. 

It’s best to get as many nutrients as possible from food rather than from supplements. If you want to spice up your diet, you can also consider cooking with oregano and other fresh herbs.

Frequently asked questions

Why trust our experts?

Written by:

Victoria Eaton, RDN, LDN, IFNCP

Victoria Eaton, RDN, LDN, IFNCP began her career in the functional medicine space in 2015. She has experience in private practice and working with individuals with digestive issues, chronic migraines, and macular degeneration.

Edited by:

Alex Eastman, PhD, RN

Alex Eastman, PhD, RN, is a California-based registered nurse and staff medical editor at GoodRx, where he focuses on clinical updates and Latino health.

Reviewed by:

Farzon A. Nahvi, MD

Dr. Nahvi is an emergency medicine physician and author of “Code Gray: Death, Life, and Uncertainty in the ER.” He works clinically at Concord Hospital in Concord, New Hampshire, and is a clinical assistant professor of emergency medicine at the Geisel School of Medicine at Dartmouth. Prior to this, he worked as an ER physician and clinical assistant professor of emergency medicine at the Mount Sinai Health System, NYU Langone Health, NYC Health + Hospitals/Bellevue, and the Manhattan VA. He is a graduate of Cornell University and NYU School of Medicine.

Our editorial standards

Meet our experts