Oregano Uses and Plant Monograph
Oregano is commonly found in many spice cabinets and it’s most often thought of as a simple culinary herb. However, oil of oregano, or oregano essential oil, is one of the most popular herbal preparations on the market today! It’s easy to find oil of oregano in practically every single health food store in the US.
In researching this article, I looked through dozens of herbal books and it was rare to find oregano listed. It’s surprising that this potent and effective plant is so often overlooked.
Oregano is originally from the Mediterranean and the Greeks have a special history with this spicy plant. The word oregano comes from two Greek words meaning “joy” and “mountains.” In Greek mythology, oregano was created by Aphrodite and grown in her garden on Mount Olympus. Oregano loves to grow in hot conditions with well-drained soil. You can guess that it thrives in Greece’s sunny climate.
Oregano is an important culinary and medicinal herb all around the Mediterranean, including in North Africa, Italy, and the Middle East. It’s widely reported that oregano did not become popular in the US until after World War II, when soldiers brought it back from southern Italy.
Oregano Uses & Plant Profile Summary:
- Botanical Name: Origanum vulgare
- Family: Lamiaceae (mint)
- Parts Used: aerial
- Energetics: hot, dry
- Taste: pungent (aromatic), bitter
- Plant Properties: antimicrobial, diffusive, carminative, stimulating expectorant, stimulating diaphoretic, anti-fungal, emmenagogue, vermifuge, high in antioxidants
- Plant Uses: infections (bacterial/fungal), cold/stagnant digestion, sore throat, cold fevers, lung congestion, delayed menses, intestinal parasites
- Plant Preparations: tea, food, tincture, vinegar, oxymel, infused oil, capsules, essential oil
Energetics
Oregano is hot and dispersive. It’s so hot that nibbling on a potent fresh leaf can leave your tongue feeling a bit numb! The heat from oregano is diffusive in nature and it is used to break up stagnation in the respiratory system, digestive tract, and female reproductive system. The whole herb can be used regularly by someone who has a long-term constitutional tendency to cold and damp conditions, and used in the short term by anyone who has acute cold and damp symptoms.
Digestion
As a culinary herb, oregano excels as an herb for digestion. Who doesn’t want their medicine to taste good? Its signature flavor is famous in tomato dishes such pizza and marinara sauce for pasta, and it is commonly used in spice blends like za’atar, herbes de Provence, and adobo seasoning.
Oregano’s hot and dispersive nature makes it ideally suited when someone has symptoms of cold, damp, and stagnant digestion. Symptoms of this include slow stomach emptying, a heavy feeling in the gut long after eating, flatulence, belching, a thick white coating on the tongue, feeling frequently bloated, and slow transit time in the bowels.
To support healthy digestion on a day-to-day basis, oregano can be used in small amounts as a seasoning in meals. To address the more upsetting symptoms of cold and stagnant digestion, I recommend using it as a strong tea or even as a tincture.
There is some evidence that oregano can help dispel parasites from the intestines. A small, older clinical trial in humans showed that people taking six weeks of supplementation with 600 mg emulsified oil of oregano daily had a decrease in enteric parasites.1
Antimicrobial
Oregano is a strong antimicrobial herb that has been shown to be effective against a variety of bacteria and fungi in vitro.2 3 4 5 One randomized, double-blind study showed that an oregano extract ointment decreased bacterial contamination and infection of post-surgical wounds.6
For external use, oregano can be brewed as a tea or used as a diluted tincture as a wash to inhibit pathogens on the skin. It is often used internally for digestive pathogens. Internally, I recommend using it as a tea or tincture rather than an essential oil (see discussion below). When using the essential oil externally, it needs to be properly diluted (dilution amount varies depending on a person’s sensitivity).
Oregano tea or diluted oregano tincture can be used as a mouthwash; for best results, swish for several minutes (and up to 20 minutes) at a time.
Colds and the Flu
Oregano can be used to disperse cold and stagnant conditions associated with a cold or the flu (influenza). Prepared as an herbal steam, it can break up congestion in the sinuses and lungs. The infused honey or tea can relieve the pain of a sore throat. When feeling chilled due to a fever, oregano tea or a bath made with oregano tea can support the fever process by helping the body to heat up.
Delayed Menses
Oregano also moves stagnation within the pelvis and has been used for hundreds of years as a way to stimulate delayed menstruation, the herbal action called emmenagogue. It is especially indicated when there are accompanying signs of coldness. Because of this, oregano is contraindicated in large doses (beyond culinary use) during pregnancy.
Chemical Constituents of Oregano
I am occasionally asked why I don’t include a list of constituents in my herbal monographs. The simple answer is that the information doesn’t often interest me, nor does it ever guide me in my own herbal experiences.
I also know that to simplify an herb down to its constituents is often misleading. Isolated constituents don’t act in the body in the same way that whole herbs do. Constituents are also not set in stone; they change as the plant changes. A chemical analysis of a plant has simply captured a snapshot of that plant in that particular space and time. As a plant goes through its life cycle, its constituents change. This could be through the growing season or even through a several-year life span.
It’s also a bit of a pet peeve of mine when people make claims (either positive or negative) about whole herbs based on studies using isolated chemical constituents.
Which is not to say that chemical analysis of herbs is useless! That information can certainly guide us and offer insights into the plants. Some herbalists love to study constituents, hoorah! My caution is to avoid relying too rigidly on constituents, and especially to hold tight to the practical experience of whole plant medicine.
With that being said, there has been a lot of research on two primary constituents within oregano, so let’s take a look.
Oregano is exceptionally high in carvacrol, a phenolic monoterpenoid that is also found in bee balm (Monarda fistulosa, M. punctata, M. didyma) and thyme (Thymus vulgaris). According to the James Duke Phytochemical and Ethnobotanical Database, oregano is the highest source of carvacrol. No human clinical trials have been done on carvacrol, but numerous in vitro studies have shown it to be antimicrobial, antioxidant, and to have anticancer properties.7
Thymol is another phenolic monoterpenoid that has been highly studied as medicine, in cosmetics, and also as a food preservative. (It is also found in thyme and bee balm.) Thymol is commonly used in mouthwashes (including Listerine®). One study showed that a varnish using chlorhexidine and thymol resulted in reduced gingival (gum) inflammation.8 Thymol is commonly used by beekeepers to inhibit Varroa destructor mites that parasitize and weaken bee colonies.
Oregano Essential Oil
Oregano currently is very popular as an essential oil. It is often sold as “oil of oregano,” which is the essential oil diluted in a carrier oil such as olive oil.
There’s no doubt that the oil of oregano preparation is potent. I think people are often drawn to this powerful remedy because its effects are immediate and forceful. However, there are lots of safety issues associated with this preparation. Exceeding safe dosages is easy. While I was in clinical practice, I worked with several people who were dealing with long-term negative effects of taking oil of oregano.
I most often reach for whole herb medicines because they are safer and often even more effective than highly refined essential oils. I urge caution when choosing to use oil of oregano, paying attention to taking appropriate doses and also to appropriate duration of dosing (i.e., don’t take it for too long). If you are trying to use pure oregano essential oil for internal dosing, please work with an experienced practitioner who can show you the appropriate way to dilute the essential oil so as not to burn or damage your mucous membranes.
Differences Among Oregano, Marjoram, Bee Balm, and Thyme
Oregano, marjoram, bee balm, and thyme contain similar constituents. They are often somewhat interchangeably used in herbal medicine. Using your senses, like taste and smell, is the best way to explore how you may want to use an herb. For example, marjoram often has a milder taste and smell than oregano. One species of bee balm, Monarda fistulosa, is often spicier than other species (e.g., Monarda didyma). Any of these plants can be more or less potent depending on growing conditions as well as harvesting and preserving methods.
Of these plants, oregano and marjoram (Origanum majorana) are the most similar in appearance and there is often a lot of confusion regarding them. Adding to the confusion is that one of oregano’s common names is wild marjoram, while true marjoram is sometimes called sweet marjoram. The easiest way to tell these similar looking plants apart is by taste and smell. Oregano has a spicier and more pungent taste and smell than marjoram. Marjoram is often described as being woodsy and floral in scent and flavor. While the foliage of the two plants is quite similar, the flowers differ. Marjoram flower buds have bracts that look like tiny green pine cones until they blossom.
In my opinion of their medicinal qualities, oregano is very similar to bee balm and somewhat similar to thyme. Oregano and marjoram are quite different in taste, smell, and use. Marjoram also has medicinal benefits; for example, one pilot study showed that marjoram could improve insulin sensitivity for people with polycystic ovary syndrome.9
Plant Preparations
Oregano is easy to grow in the garden or in a container. It loves hot and dry conditions with quickly draining soil. Overwatering oregano can dilute its flavor. Oregano grown in cold and damp climates may not be as spicy.
Oregano can be used either fresh or dried, but it is often preferred dried. Drying oregano concentrates its aromatic oils and gives it a strong flavor.
Remember how I mentioned that the chemical constituents within a plant can change over time? If you have oregano growing near you, then you can taste this transformation yourself simply by nibbling the leaves throughout the growing season. Doing this myself, I’ve come to recognize that I don’t love oregano after it’s fully flowering, when the taste goes from being wonderfully aromatic to somewhat resinous.
Oregano, of course, is a delicious culinary herb that is most commonly used in tomato dishes. Cuisines from around the world use oregano in varied ways. I love it in my own za’atar blends and also in my red enchilada sauce. Oregano is fairly strong in flavor; oftentimes a small amount is best.
Oregano can be made into a tea, with dried oregano working best. The fresh leaves work well when infused into honey. The leaves can be extracted into vinegar or an oxymel, which is a combination of vinegar and honey. Oregano isn’t commonly seen as a tincture, but that method works as well.
As mentioned, the essential oil is commonly used. I urge caution when using oregano essential oil internally or externally as this potent preparation can easily burn sensitive skin and cause other negative effects.
Dosage Suggestions
- Tea: 5-10 grams dried leaves and flowers per day
- Tincture (fresh): 1:2, 40%. 2-4 mLs, three times a day
Special Considerations
Using oregano in larger-than-culinary amounts, or as an essential oil, is generally contraindicated in pregnancy because of its emmenagogue effects.
Footnotes
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