How to Use Oregano Oil?

In our companion article on the benefits and side effects of oregano oil, we covered what the research says about this popular essential oil. But knowing that oregano oil has antimicrobial properties in laboratory studies doesn’t tell you much about how to actually use it safely at home.

That’s what this article addresses: the practical side of oregano oil. How do you dilute it? What’s a reasonable dose? And when should you avoid it altogether?

A word of caution before we start: if you’re taking medications or have any health conditions, talk to your doctor before using oregano oil. This isn’t just boilerplate advice - oregano oil has real interactions with blood thinners, diabetes medications, and other drugs. The contraindications matter.

Understanding Oregano Oil Products

Walk into a health food shop and you’ll find oregano oil sold in several forms. Understanding the differences helps you choose appropriately.

Essential oil (concentrated) - This is pure oregano oil extracted by steam distillation. It’s extremely potent and must always be diluted before use. A small 15ml bottle might last months because you’re using drops, not spoonfuls. Look for products that list the carvacrol percentage - the main active compound. Quality oils typically contain 60-80% carvacrol.

Oil of oregano (diluted) - Some products come pre-diluted in a carrier oil like olive oil. These are safer for direct use but check the dilution ratio. A typical ratio might be 1:4 (one part oregano oil to four parts carrier oil).

Capsules and softgels - These contain measured doses of oregano oil, often standardised to a specific carvacrol content. They’re convenient for oral supplementation and remove the guesswork around dilution. Most products provide 100-250mg per capsule.

Lozenges - Designed for throat and mouth issues, these dissolve slowly and deliver oregano oil directly to oral tissues.

The form you choose depends on what you’re using it for. Topical applications need diluted essential oil. Oral supplementation is easier with capsules. Let’s look at each use case in detail.

Topical Applications

Oregano oil’s antimicrobial properties have led to various topical uses. Laboratory studies show activity against bacteria and fungi, though human clinical trials remain limited [1].

The Golden Rule: Always Dilute

Undiluted oregano oil will burn your skin. This isn’t a mild irritation - it can cause genuine chemical burns, blistering, and lasting damage. I’ve heard from people who learned this the hard way after applying neat oregano oil to athlete’s foot. Don’t be one of them.

Safe dilution ratio: Mix 1-2 drops of oregano essential oil with approximately 10ml (2 teaspoons) of carrier oil. Good carrier oils include:

• Extra virgin olive oil (traditional choice)
• Fractionated coconut oil (absorbs well, doesn’t stain)
• Jojoba oil (closest to skin’s natural sebum)
• Sweet almond oil (gentle, good for sensitive areas)

For your first use, start with the lower concentration (1 drop per 10ml) and see how your skin reacts. You can always increase the concentration if needed, but you can’t undo a burn.

Fungal Skin Infections

Athlete’s foot and other superficial fungal infections are among the most common reasons people reach for oregano oil. The antifungal activity of carvacrol and thymol (oregano oil’s main components) has been demonstrated in laboratory studies [2].

Foot soak method:

1. Fill a basin with warm water (not hot)
2. Add 5-10 drops of oregano oil per litre of water
3. Soak affected feet for 15-20 minutes
4. Dry thoroughly, especially between toes
5. Repeat daily until symptoms improve

Direct application method:

1. Mix 1-2 drops of oregano oil with 10ml of carrier oil
2. Apply a thin layer to the affected area
3. Allow it to absorb - don’t cover immediately
4. Apply twice daily

If you don’t see improvement after two weeks, or if the infection spreads, see a doctor. Fungal infections can be stubborn, and some require prescription antifungal medications.

Nail Fungus

Nail fungus (onychomycosis) is notoriously difficult to treat because the infection sits beneath the nail plate. Even prescription treatments have modest success rates. Oregano oil is sometimes suggested as a natural alternative, though I wouldn’t stake much on it for established infections.

Application method:

1. Trim and file affected nails to reduce thickness
2. Apply diluted oregano oil (same ratio as above) directly to the nail and surrounding skin
3. Use twice daily, allowing the oil to absorb before putting on socks or shoes
4. Continue for several months - nail infections take time to grow out

Honestly, the evidence for oregano oil treating nail fungus is weak. If you have a persistent nail infection, a GP can prescribe oral antifungals (like terbinafine) that actually reach the nail bed. Oregano oil might be worth trying for very mild cases, but set your expectations appropriately.

Minor Cuts and Scrapes

The antimicrobial properties of oregano oil suggest potential use for preventing wound infections. However, this application requires particular caution.

My honest take: For most minor cuts, cleaning with soap and water is sufficient. The human immune system handles everyday bacteria quite well. If you want to use oregano oil, apply only to intact skin around the wound, not in the wound itself. Oregano oil may irritate damaged tissue and could theoretically delay healing rather than help it.

For anything more than a minor scrape - deep cuts, puncture wounds, animal bites - get proper medical attention. Oregano oil isn’t a substitute for stitches or tetanus shots.

Insect Bites and Stings

When a mosquito bites, it injects saliva that triggers a localised allergic reaction - the familiar itchy bump. Oregano oil’s anti-inflammatory properties might help reduce this reaction.

Application method:

1. Mix 1 drop of oregano oil with 5ml of carrier oil
2. Apply a small amount to the bite
3. Reapply every few hours as needed

This is a traditional use that makes theoretical sense given oregano oil’s anti-inflammatory components, but don’t expect miracles. A hydrocortisone cream from the chemist is probably more effective for severe itching.

Oral Use

Taking oregano oil internally is more controversial than topical use. The concentrated oil can irritate the digestive tract, and there’s less research on appropriate oral doses.

Capsules: The Safer Option

If you want to take oregano oil orally, capsules are generally safer and more convenient than liquid oil. The oil is contained within the capsule shell, reducing the risk of burning your mouth or oesophagus.

Typical dosing from commercial products:

• 100-250mg of oregano oil per capsule
• Often standardised to contain 55-80% carvacrol
• Usually taken 1-3 times daily with food

Follow the product label instructions. Taking oregano oil capsules with food may reduce stomach upset.

Duration considerations: Most sources suggest limiting oral oregano oil use to 2-4 weeks at a time. Like antibiotics, oregano oil’s antimicrobial activity isn’t selective - it may affect beneficial gut bacteria along with harmful organisms. For maintaining healthy gut flora, see our article on probiotics.

Sublingual Use (Under the Tongue)

Some practitioners recommend placing diluted oregano oil under the tongue for faster absorption. This method delivers the oil directly into the bloodstream via the sublingual blood vessels, bypassing the digestive system.

Method:

1. Mix oregano oil with a carrier oil at a 1:1 ratio
2. Place 1-2 drops under the tongue
3. Hold for 30-60 seconds, then swallow
4. Rinse your mouth with water if the taste is unpleasant

This isn’t the most pleasant experience. Oregano oil has a strong, pungent flavour that many find overwhelming. The burning sensation under the tongue is also uncomfortable, even with dilution. If you’re considering sublingual use, capsules are probably a more practical alternative.

Gargling for Throat Discomfort

For sore throats and mouth issues, gargling with diluted oregano oil is a traditional remedy. The antimicrobial properties may help reduce oral bacteria.

Method:

1. Add 2-3 drops of oregano oil to a cup of warm water
2. Stir well (the oil won’t fully dissolve)
3. Gargle for 30 seconds without swallowing
4. Spit out and rinse with plain water

The evidence for this is largely anecdotal. If you have a persistent sore throat lasting more than a week, see a doctor rather than continuing to gargle oregano oil.

Steam Inhalation

Inhaling oregano oil vapour is a popular home remedy for respiratory congestion, sinus issues, and cold symptoms. The steam helps deliver volatile compounds to the respiratory tract.

Method:

1. Boil water and pour into a heat-safe bowl
2. Add 3-5 drops of oregano oil
3. Drape a towel over your head and the bowl
4. Breathe in the steam for 5-10 minutes
5. Keep your face at a safe distance to avoid burns

Safety notes:

• Keep your eyes closed during inhalation
• Don’t lean too close - steam can burn
• Stop immediately if you feel any breathing difficulty
• Not recommended for children or people with asthma (steam and strong vapours can trigger bronchospasm)

Steam inhalation is generally soothing for congestion regardless of what you add to it. Whether oregano oil specifically adds benefit beyond plain steam is unclear. A systematic review found limited evidence for any essential oil steam inhalation in treating respiratory infections [3].

Making Oregano Tea

If you’d prefer a gentler approach, oregano tea provides some of the herb’s beneficial compounds without the intensity of concentrated oil. This is much safer than essential oil and can be consumed more regularly.

Fresh oregano tea:

1. Strip fresh oregano leaves from the stem (about 2 tablespoons)
2. Bruise or chop the leaves to release the oils
3. Place in a cup and pour over 250ml of boiling water
4. Cover and steep for 15-20 minutes
5. Strain and drink warm, with honey if desired

Dried oregano tea: Use 1-2 teaspoons of dried oregano per cup, steeped the same way.

Oregano tea has a pleasant, savoury flavour - rather like drinking a mild Italian herb broth. It’s traditionally used for digestive discomfort, mild respiratory symptoms, and general wellness. Don’t expect the potent antimicrobial effects of concentrated oil, but it’s a much safer way to incorporate oregano into your routine.

Who Should Avoid Oregano Oil?

Certain people should avoid oregano oil entirely or use it only under medical supervision:

Bleeding disorders and blood thinner users - Oregano oil may have anticoagulant effects. If you take warfarin, aspirin, clopidogrel, or other blood thinners, avoid oregano oil. The same applies if you have haemophilia or other bleeding disorders, or if you’re scheduled for surgery within two weeks.

Pregnancy and breastfeeding - There’s insufficient safety data for pregnant or nursing women. The oil may affect hormone levels and could potentially stimulate uterine contractions. Best avoided entirely during pregnancy.

Children - Concentrated oregano oil hasn’t been studied for safety in children. Keep it well out of reach - ingesting undiluted oil could seriously harm a child.

Allergies to mint family plants - If you’re allergic to basil, mint, sage, rosemary, thyme, or lavender, you may react to oregano oil. These plants share allergenic compounds.

Diabetes medication users - Oregano oil may lower blood sugar, potentially causing hypoglycaemia when combined with diabetes medications. Monitor blood sugar closely if you use both.

Liver or kidney disease - The body must metabolise and eliminate oregano oil’s components. Impaired liver or kidney function may affect this process.

For a complete list of contraindications and drug interactions, see our main oregano oil article.

Quality and Storage

Not all oregano oil products are equal. Here’s what to look for:

Quality indicators:

• Botanical name (Origanum vulgare or Origanum minutiflorum) on the label
• Carvacrol percentage stated (60-80% is typical for quality oil)
• Country of origin (Mediterranean sources are traditional)
• Organic certification if important to you
• Dark glass bottle to protect from light degradation

Storage:

• Keep in a cool, dark place
• Ensure the cap is tightly sealed
• Don’t store in plastic containers (the oil can degrade plastic)
• Check the expiration date - essential oils do oxidise over time

Expect to pay more for quality oregano oil. Very cheap products may be diluted or derived from inferior oregano species with lower carvacrol content.

Realistic Expectations

Oregano oil has genuine antimicrobial properties in laboratory studies. Carvacrol and thymol do kill bacteria and fungi in petri dishes. However, laboratory results don’t automatically translate to human health benefits.

What we know:

• The compounds in oregano oil have antimicrobial activity
• Topical applications are relatively well-tolerated when properly diluted
• Short-term oral supplementation appears safe for healthy adults
• Some traditional uses have theoretical support

What remains uncertain:

• Whether oregano oil effectively treats infections in humans
• Optimal dosing for specific conditions
• Long-term safety of regular supplementation
• Comparative effectiveness versus conventional treatments

I wouldn’t recommend oregano oil as a substitute for medical treatment of genuine infections. Urinary tract infections, for example, need proper antibiotics - not essential oils. But for minor topical issues, prevention-focused use, or as a complement to conventional care, oregano oil is a reasonable option for those who want to try natural approaches.

Summary

Using oregano oil safely comes down to a few key principles:

1. Always dilute for topical use (1-2 drops per 10ml carrier oil)
2. Start low with doses and concentrations, increasing only if tolerated
3. Limit duration of oral use to 2-4 weeks
4. Know the contraindications - especially blood thinners, pregnancy, and allergies
5. Don’t replace medical care for serious infections or conditions

If you’re new to oregano oil, capsules for oral use and pre-diluted preparations for topical use are the safest starting points. Work your way up to using pure essential oil only after you understand proper dilution and have confirmed you don’t have adverse reactions.

References

1. Nostro A, et al. Susceptibility of methicillin-resistant staphylococci to oregano essential oil, carvacrol and thymol. FEMS Microbiol Lett. 2004;230(2):191-5.
2. Hammer KA, et al. In-vitro activity of essential oils, in particular Melaleuca alternifolia (tea tree) oil and tea tree oil products, against Candida spp. J Antimicrob Chemother. 1998;42(5):591-5.
3. Kania-Richmond A, et al. Steam inhalation therapy for respiratory tract infections: A systematic review. Complement Ther Med. 2020;49:102328.