Oregano is a popular kitchen favourite and a valuable home remedy for a number of acute (short-lived, self-limiting) conditions. It has many benefits for health as a potent antioxidant and it also helps to support the microbiome (1,9,10). Oregano can be used fresh or dried and drunk as an infusion (tea) for simple conditions in the digestive and respiratory systems, as well as to treat minor infections.

It is considered tonic to the lungs and has a specific affinity for conditions in the upper respiratory tract. It may be used as an ointment or nasal spray to treat irritated skin around the nostrils. Options for prepared nasal sprays with oregano can be found in health food shops or online. Boiling water can be poured over the fresh or dry herb, or the essential oil, for topical application or for use as a steam inhalation. An oregano ointment applied around the nose and surrounding skin – taking care to avoid the eyes – can be used to gently combat an upper respiratory infection. Taken as a tea or tincture, oregano helps to treat symptoms of the common cold by addressing the infection, speeding up recovery.

Taken internally as a tea or tincture, herbalists use oregano to relieve symptoms of mild, spasmodic gastrointestinal complaints such as bloating and flatulence. It supports the digestive function and assimilation of nutrients. Due to its antispasmodic activity, it is also helpful for intestinal cramping. Many kitchen herbs, including oregano, also possess prebiotic‐like effects (10). Prebiotics are typically, but not limited to, foods high in fibre that support the gut microbiome, promoting the growth of mutualistic (beneficial) bacterial species (1, 9). Combined with its specific antibacterial qualities, oregano provides support for overall microbial health in the digestive system. While it may seem counter-intuitive, many medicinal plants have seemingly paradoxical actions which, taken together, aid in maintaining good health.

One of the most well researched actions of oregano is the treatment of infections. It can be made into an ointment for external use only by fixing an infused oil with a harder wax or adding oregano essential oil to a carrier oil. Topical application of oregano ointment can be used to improve healing whilst also reducing the chances of infection in minor wounds, cuts or grazes (3). It can also be used to treat fungal infections such as ringworm, athlete’s foot or toenail fungus when applied topically. It has even been shown to have local antiviral action when applied directly to the skin, which can be helpful in viral skin infections (7). As a mouthwash, oregano can help improve oral health due to its antimicrobial and anti-inflammatory effects, particularly where there is infection or gingivitis.

Research has determined that oregano and its chemical components are antibacterial against 30 different human pathogens organisms including E. coli, Salmonella species, Staphylococcus species and Giardia parasites (1,7). It can be used to help during acute infections as an internal medicine taken in the correct dosage. For serious infections, consult with a doctor as antibiotics may be required. Oregano oil is often what is thought to be most potent and effective to treat fungal or bacterial infections. It is now widely available over the counter in health food stores – it is important to choose a high quality product to ensure quality and efficacy.

Energetically, oregano is warming and drying. The volatile oils in aromatic plants like oregano are largely responsible for this stimulating, energising effect. These are used where there is stagnation due to a depressed state of tissue function. Matthew Wood describes this tissue state as ’a deep cold within an organism from the dying down of the innate heat of life – and not from mere cold exposure’ (6). This means that the tissues are under functioning on a systemic level and there will likely be infective tendencies or susceptibilities, putrefaction and ‘dead’ energy in the body. 

Oregano is specific for this ‘depressive’ state – which refers to both depressiveness or under function of the tissues, but also depressiveness of the mind. Oregano elevates, rejuvenates and enlivens by improving the flow of blood to all the tissues.

Oregano’s warming action is carried out by increasing the circulation, enlivening the tissues and invigorating the constitution. These warming, aromatic stimulants also open up the lungs, enabling them to deliver more life giving oxygen to the cells (6). Their effects are far reaching throughout the body and are enhanced by their antioxidant effects, optimising and enhancing health in all body tissues.

Oregano has been used for centuries to treat respiratory conditions such as asthma, bronchitis and coughs. It was also widely applied throughout history in Europe for conditions in the gastrointestinal system such as diarrhoea, indigestion and stomach ache.

In Greece, oregano was used both internally and externally as a fomentation (a topical application of hot, herb-infused liquid via a cloth pack to ease pain and inflammation) to treat skin conditions, localised infections, dropsy (oedema) and convulsions. In ancient Egypt, oregano was used as both a preservative and an antidote to poisons and insect stings (11).

Immune system

Oregano has been studied extensively as a powerful, broad-spectrum antibacterial, anti-fungal, antioxidant, and anti-inflammatory agent (13). Unique constituents found in oregano known as origanol A and origanol B have potent anti-inflammatory and antioxidant activity (1).

Volatile oil extracts of thymol and carvacrol from oregano have shown significant antioxidant and antimicrobial activity in vitro, leading to the destruction or growth inhibition of a broad spectrum of microorganisms including Escherichia coli, Staphylococcus aureus, Listeria innocua and L. monocytogenes, Saccharomyces cerevisiae, Aspergillus niger, Bacillus cereus, Bacillus subtilis, Candida albicans, and Eimeria tenella (1).

Oregano oil has also been found to completely inhibit the growth of Candida albicans in a laboratory culture, as well as the germination and mycelial growth of C. albicans (1). Herbalists may use oregano among other herbs to address intestinal dysbiosis, along with vital dietary and lifestyle measures such as reducing sugar intake. Reducing sugar during the treatment of fungal infections or dysbiosis is essential as pathogenic fungi and bacteria thrive on sugars.

Like many herbs with antimicrobial actions, oregano also has immunomodulating activity (14), meaning that it assists the human immune system in tackling an infection on multiple levels. 

Digestive system

Oregano has many benefits for the digestive system. Due to its positive effects on the microbiome it may be used for small intestine bacterial overgrowth (SIBO). Oregano along with other herbs such as Pau D’Arco, olive leaf, and sage were included in a study that showed significant improvements for patients with SIBO after taking herbal medicines. The study also acknowledged that those treated with herbs felt significantly better than those who used antibiotic rifaximin (8).

Oregano oil is a strong antibacterial and can inhibit Escherichia coli, Salmonella species, Staphylococcus aureus and Campylobacter species. It is also thought that oregano is helpful in increasing the beneficial Lactobacillus species in the gut, contributing to a balanced microbiota (9).

Anti-parasitic activity has also been identified for oregano oil against Entamoeba hartmanni, Endolimax nana and Blastocystis hominis. A herbalist may use oregano oil for the treatment of parasites along with the necessary dietary and lifestyle measures such as reducing sugar and refined food intake as this is vital to reduce parasite load. 

Herbalists will often include a detoxification protocol alongside any treatment for parasites or fungal infections. This is because some parasites and fungi produce low-molecular-weight die off toxins. Many people can be affected by parasitic, fungal or bacterial infections and imbalances, so the unique symptoms of the patient would need addressing and support thereafter to ensure a state of optimum health is restored. 

Cellular and metabolic

Oregano has a strong antioxidant capacity, partly due to the presence of phenolic compounds carvacrol and thymol. These antioxidants help to reduce oxidative damage caused by metabolism, helping to prevent mutagenesis (the process by which potentially damaging genetic mutations and epigenetic changes occur), carcinogenesis (the process of cancerous tumour formation) and ageing due its free radical scavenging properties (8). A herbalist may combine oregano with other herbs to enhance cellular health and resilience to make good use of oregano’s chemopreventive properties. 

Additionally, oregano helps to regulate cholesterol levels, which may be useful as part of a treatment approach to address hyperlipidaemia, alongside lifestyle and dietary changes. It has been shown to increase high-density lipoprotein (HDL – healthy) cholesterol and significantly reduce low density lipoprotein (LDL – unhealthy), the balance of which can be a key part of reducing the risk of vascular disease (8).

There are a small number of clinical trials as well as some valuable in vitro and lab studies that focus on a number of oregano’s chemical compounds. A number of these studies have been summarised below to demonstrate the mechanism of action for some of the medicinal uses discussed in this monograph. 

Animal studies are not condoned by Herbal Reality, however for the purpose of including research from which some understanding of therapeutic actions can be confirmed, some animal studies have been included herein.

A review of oregano

In a sytematic review, oregano was found to possess a number of therapeutic properties identified in a range of in vitro and in vivo studies. These include antibacterial, anti-fungal, antioxidant, and anti-inflammatory properties. Unique constituents found in oregano, known as origanol A and origanol B, were most closely associated with anti-inflammatory and antioxidant activity (1).

Carvacrol, another constituent found in oregano, is believed to inhibit biofilm formation by disrupting the cell membrane integrity of bacteria. Carvacrol and thymol, both found in oregano, are thought to synergistically inhibit bacterial growth, and can therefore be useful in addressing infection. Interestingly, both thymol and carvacrol also demonstrated antispasmodic activity in vitro. It is thought that this was due to these compounds altering calcium activity in muscle and nerve cells, which is an important part of the biochemical signalling that leads to movement. In smooth muscle (the type of muscle in the digestive tract, respiratory tract and blood vessels, these oregano constituents may be reducing spasm and tension (1).

Other oregano actions identified by the review included being antioxidant, antimalarial to an extent, and cytotoxic (toxic to cells) to breast cancer cells (1). Different extraction methods showed different results; oregano extracted using water showed the highest antioxidant activity while the ethyl acetate and ethanol (alcohol) extracts showed activity against human breast cancer cells. Oregano essential oil (note: this is not the same as oil of oregano) showed the most significant results concerning anti-malarial activity. The study did not include a method of administration or dose. This is also a reference to in vitro research which does not directly relate to the use of oregano in human subjects. Further clinical research is required to evaluate the potential for oregano in the treatment of malaria (a serious infection) in humans.

Rhinosinusitis: A clinical study

A double-blind clinical placebo-controlled trial was carried out to investigate the effects of oregano oil nasal spray to treat patients with chronic rhino-sinusitis (CRS) (2). 75 adult patients with CRS participated in this study. Participants were randomised to receive a nasal spray containing either oregano oil (intervention group), fluticasone (control group) or sesame oil (placebo group) over a period of 4 weeks. The study results show that symptoms such as nasal blockage, rhinorrhea, headache, facial pain and anosmia (lacking sense of smell) decreased markedly in the oregano group (2).

Wound healing: A clinical study

A randomised double blind controlled study was carried out to determine the efficacy of 3% oregano extract ointment on wound healing (3). Forty subjects who underwent surgery were recruited. The study identified a lower incidence of Staphylococcus aureus in the wounds of the group treated with oregano, as well as a statistically significant improvement over petrolatum in scar colour, pigmentation, and pliability. The study concluded that oregano ointment decreased bacterial contamination and subsequent infection on post-surgical wounds as well as demonstrating wound healing activity (3).

Anti-parasitic: A clinical study

A small human study was carried out on 14 adult subjects to identify possible anti-parasitic activity of oregano oil. The oregano oil was orally administered. The subjects in the study had all been confirmed infected with gut parasites: Blastocystis hominis, Entamoeba hartmanni and/or Endolimax nana via stool sample. 

After 6 weeks of supplementation with 600 mg emulsified oil of oregano daily, there was complete disappearance of Entamoeba hartmanni (four cases), Endolimax nana (one case), and Blastocystis hominis in eight cases. Also, Blastocystis hominis scores declined in three additional cases. Gastrointestinal symptoms improved in seven of the 11 patients who had tested positive for Blastocystis hominis (4).

Oregano’s genus name probably comes from the Greek words ‘oros’ meaning ‘mountain’ and ‘gamos’ meaning ‘joy’ (12). This reference is due to the native habitat of oregano in mountain areas where it is appropriately referred to as ‘joy of the mountain’.

Oregano is native to the hills and mountains of Mediterranean countries and western Asia.

The IUCN Red List of Threatened Species database has not yet assessed oregano for its endangered rating.

Habitat loss and over harvesting from the wild are two of the biggest threats faced by medicinal plant species. There are an increasing number of well known herbal medicines at risk of extinction. We must therefore ensure that we source our medicines with sustainability in mind. 

The herb supplement industry is growing at a rapid rate and until recent years a vast majority of medicinal plant produce in global trade was of unknown origin. There are some very real and urgent issues surrounding sustainability in the herb industry. These include environmental factors that affect the medicinal viability of herbs, the safety of the habitats that they are taken from, as well as the welfare of workers in the trade.

The botanical supply chain efforts for improved visibility (transparency and traceability) into verifiably sustainable production sites around the world is now certificated through the emergence of credible international voluntary sustainability standards (VSS). Read our article on sustainable sourcing of herbs to learn more about what to look for and questions to ask suppliers about sustainability.

Herbal Medicines are often extremely safe to take, however it is important to buy herbal medicines from a reputed supplier. Sometimes herbs bought from disreputable sources are contaminated, adulterated or substituted with incorrect plant matter.

Some important markers for quality to look for would be to look for certified organic labelling, ensuring that the correct scientific/botanical name is used and that suppliers can provide information about the source of ingredients used in the product.

A supplier should be able to tell you where the herbs have come from. There is more space for contamination and adulteration when the supply chain is unknown.

Oregano is easy to grow indoors and outdoors in temperate regions.

Seeds can be sown indoors in the spring to plant out once the risk of frost has passed. Seeds can be sown directly outdoors once the soil has warmed up in late spring but seedlings are slow to grow and are easier to manage when sown in pots or trays. Sow on the surface and press into the soil.

Oregano is a tough perennial which can grow in poor soils and once established requires little maintenance.

Oregano ointment

Oregano ointment can be used directly on the skin to treat a range of skin inflammations and in first aid for minor cuts and grazes. Oregano is also useful for slow healing wounds and treating fungal infections of the skin. This balm can be used as needed, up to 3 times a day.

Ingredients:

• Oregano-infused oil (not to be confused with essential oil) can be bought or made at home (see our article on simple home herbalist recipes for more details on how to make an infused oil).
• Oregano essential oil (10-15 drops)
• Beeswax (unfiltered pellets or solid form) or plant-based wax e.g. carnuba. 

Method:

• Using a double boiler/ Bain Marie or a water bath method, on gentle heat. Add your infused oil to the clean pan.
• Add around 8- 12 % beeswax (of the total infused oil quantity i.e. 100ml infused oil should have approx 10- 12g of wax) and gently stir with a silicone or wooden spoon until the wax has fully dissolved into the oil. Remove from the heat.
• You can add an essential oil at this stage if desired; approx 10 drops (depending on what is being used). Essential oils act as a preservative but also help to assist circulation and better absorption into the skin.
• Slowly pour the mixture into a clean, dark glass jar. Cover but do not close the lid firmly until the balm has fully set/ solidified.
• Label your jar and close the lid firmly. Store in a cool, dark place. Balms/ Salves/ Ointments should last for up to a year.

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