Post Author: Victoria Tyler

How long  and what dosage to take Oregano Oil for Small Intestinal Bacterial Overgrowth (SIBO)

Lately, I have seen a growing number of clients turning to herbal supplements to manage Small Intestinal Bacterial Overgrowth (SIBO) after reading about them online. Many have used AI chatbots or online forums for dosage recommendations, which has led to questions about the effectiveness and safety of oregano oil and SIBO patients. In this article, we will explore the benefits of using oregano oil capsules as a natural remedy for SIBO and the dangers of not seeking professional guidance due to side-effects.

What Is SIBO?

SIBO (Small Intestinal Bacterial Overgrowth) is a condition in which an excessive number of bacteria grow in the small intestine. Normally, the small intestine contains relatively few bacteria compared to the large intestine, but in SIBO, bacteria overgrow or migrate, leading to digestive issues. You can conduct a SIBO test to detect two gases called hydrogen and methane in your breath. If these gases are elevated this is indicative of a bacterial or methanogen overgrowth.

Common Symptoms of SIBO

• Digestive issues: Bloating, gas, diarrhoea, constipation, or a mix of both
• Nutrient deficiencies: Difficulty absorbing key vitamins like B12, iron, and fat-soluble vitamins (A, D, E, K)
• Unexplained weight changes: Weight loss that doesn’t make sense
• Brain fog and fatigue: Feeling mentally sluggish or unusually tired
• Food intolerances: Especially to high-fibre or carbohydrate-rich foods

What Causes SIBO?

Several factors can contribute to bacterial overgrowth in the small intestine, including:

• Slow gut motility: Conditions like IBS, diabetes, or hypothyroidism can slow digestion, allowing bacteria to thrive
• Low stomach acid: Stomach acid helps control bacterial populations; a deficiency can create an imbalance
• Structural issues: Adhesions, strictures, or surgeries can cause blockages that lead to bacterial build-up
• Frequent antibiotic or acid-reducing medication use: These can disrupt the gut’s natural bacterial balance

What Is Oregano?

Oregano (Origanum vulgare) is a culinary and medicinal herb widely used for its antimicrobial, antifungal, and anti-inflammatory properties. The essential oil derived from oregano contains carvacrol and thymol—compounds believed to have powerful antibacterial effects. When treating SIBO, you should not simply use oregano as a culinary herb; instead, you need to take a medicinal dosage in capsule or liquid form.

Is Oregano oil  Good for SIBO?

Yes! Oregano is our preferred herb for patients with hydrogen-dominant SIBO, although it can also be effective for those with methanogen overgrowth. Oregano oil has been studied for its antibacterial properties and is often used as a natural alternative to antibiotics for SIBO. Some practitioners recommend it as part of a broader antimicrobial protocol. However, while it may help reduce bacterial overgrowth, its effectiveness can vary based on the individual and the specific bacterial strains present.

Potential Side Effects of Oregano oil for SIBO

Oregano oil is generally safe but can cause mild side effects, such as stomach upset or allergic reactions in some people. It is best to avoid using oregano oil during pregnancy or if you have a bleeding disorder, as it may increase the risk of bleeding. Additionally, some patients find oregano difficult to tolerate, experiencing symptoms such as heartburn and constipation.

How Many Days in a Row Can You Take Oregano Oil?

Most herbal protocols we use at our clinic involve taking oregano oil for about 2–4 weeks at a time, followed by a break. Extended use without breaks may lead to gut flora imbalances or irritation. I have seen patients take oregano for extended periods—such as six months or more—but this approach rarely works and may even cause resistance and a depletion of beneficial gut bacteria.

Is Liquid Oregano or Oregano Oil Capsules Better?

It depends on the individual:

• Capsules: We prefer oregano oil capsules because they are easier to tolerate and generally lead to better outcomes.
• Liquid Oregano Oil: This form is used for patients who have difficulty swallowing capsules; however, it has a strong taste and may cause irritation if taken undiluted.

How Long Can You Take Oregano for SIBO?

Oregano oil should not be taken indefinitely. Short-term use (4–8 weeks) is generally considered safe, but prolonged use can affect gut microbiota and lead to potential side effects. The correct dosage is key, and it is important to avoid any interactions with other medications.

How Much Oregano Can I Take for SIBO – What Is the Dosage?

To use oregano oil for SIBO, consider the following guidelines:

• Dosage: Typically, 2–3 drops of liquid oregano oil diluted in water or a carrier oil, taken 2–3 times per day, or 200–600 mg in capsule form split up throughout the day. It is recommended to use enteric-coated capsules to ensure they reach the small intestine without being broken down in the stomach.
• Timing: Take oregano oil with meals to minimize potential side effects.
• Cycling: Use for 14 days or rotate with other antimicrobial herbs such as berberine, neem, or allicin, depending on whether you have hydrogen-dominant or methane-dominant SIBO.

Berberine and Oregano for SIBO

In some cases, we recommend cycling berberine and oregano for SIBO. We have found this approach effective for both hydrogen-dominant and methane-dominant SIBO. Cycling involves taking oregano for two weeks, followed by berberine for two weeks. Note that berberine can be hard to tolerate for some patients and may cause pain and diarrhoea, so it is best to consult with a qualified functional medicine practitioner.

What SIBO Symptoms Can Oregano Help With?

Oregano oil may help alleviate symptoms such as:

• Bloating
• Gas
• Diarrhoea
• Constipation
• Abdominal pain
• Indigestion

Does Oregano Kill Good Bacteria?

Yes, oregano oil has broad-spectrum antimicrobial properties, making it effective against certain bacteria, fungi, and parasites. However, it does not differentiate between beneficial and harmful bacteria, potentially killing good bacteria. For this reason, careful use is necessary. Consider taking probiotics or eating fermented foods after treatment to help restore your gut flora. SIBO treatment can be complex, and oregano oil is not a standalone solution. You will likely need to address factors such as gut motility, the migrating motor complex, diet, and rebuilding beneficial bacteria. It is always best to work with a healthcare professional—such as a functional medicine practitioner—to develop a comprehensive treatment plan that may include dietary changes (e.g., a low FODMAP diet), other antimicrobials, or prokinetics to stimulate the migrating motor complex.

Can Oil of Oregano Cure SIBO?

We have found that approximately one-third of patients—the lucky ones—respond very well to just one round (4 weeks) of oregano. However, two-thirds of patients with SIBO can experience a rebound in symptoms, whether they take Rifaximin or herbal antimicrobials like oregano. These patients may feel better for 4–6 months before their symptoms slowly return. In such cases, taking another round of oregano—along with other supplements such as berberine, neem, or Allimed—may be beneficial. In many cases, there may be other underlying causes, such as fungal overgrowth. In addition to bacterial issues, patients may also have yeast overgrowth; without addressing both problems, full improvement may not occur.

How Does Oil of Oregano Treatment Work?

Oil of oregano can help lower the bacterial load in the small intestine, which is the primary goal of SIBO treatment. Carvacrol, one of its key compounds, is responsible for killing bacteria. By reducing the number of bacteria, oregano oil can alleviate symptoms such as bloating, gas, diarrhoea, and even constipation. The goal is to eradicate harmful bacteria so that symptoms improve and patients can eventually reintroduce a broader range of foods into their diet without discomfort.

Does Oregano Cause Die-Off Symptoms?

Oregano oil can cause die-off (Herxheimer) reactions, including fatigue, headaches, nausea, bloating, and flu-like symptoms. This occurs when bacteria release toxins as they die, temporarily worsening symptoms before improvement occurs. These reactions typically last 3–7 days and usually begin within one week of treatment.

Is Taking Rifaximin More Effective Than Taking Oregano for SIBO?

When it comes to managing SIBO, many patients wonder whether the prescription antibiotic Rifaximin outperforms herbal alternatives like oregano oil. The answer isn’t as clear-cut as you might think.

Not Necessarily.
A research study conducted in 2014 (see PMC Article) found that the efficacy of certain antimicrobial treatments can be equivalent to that of Rifaximin. In many cases, herbal antimicrobials—such as those found in oregano oil—can work just as well as Rifaximin in reducing bacterial overgrowth.

Key Considerations

1. Cost:
   The high cost of Rifaximin can be a significant barrier for many patients—especially when insurance coverage is limited or unavailable. Oregano oil capsules often provide a more affordable alternative without sacrificing antimicrobial effectiveness.
2. Prescribing Practices:
   General practitioners do not routinely prescribe Rifaximin specifically for SIBO. In some cases, GPs may not be fully aware of its application for SIBO, leaving patients to seek alternative treatment options. Herbal remedies like oregano oil are readily available over the counter and are supported by research, making them an attractive option.
3. Efficacy:
   Research indicates that oregano oil capsules can offer antimicrobial benefits comparable to Rifaximin. Although individual responses vary, many patients experience similar improvements in their SIBO symptoms when using oregano oil. However, because each individual’s situation is unique, it’s important to consult with a healthcare professional to determine the best treatment plan.

Is Liquid Oregano or Oregano Capsules Better?

Both forms have their benefits:

• Liquid Oregano Oil: Suitable for patients who do not like swallowing pills. However, it has a strong taste and may cause irritation if taken undiluted.
• Capsules: Our preferred choice—if swallowing capsules is not an issue—as they tend to be easier to tolerate and have shown better outcomes.

What Are the Best Oregano Brands?

Choosing a high-quality oregano oil is essential for effectiveness. Some reputable brands include:

• Biotics
• Gaia Herbs
• North American Herb & Spice (Oreganol)
• Designs for Health
• Pure Encapsulations

Look for brands that provide a high percentage of carvacrol and ensure that the product is free from unnecessary additives.

Potential Side Effects of Oregano

Oregano oil is generally safe but can cause mild side effects such as stomach upset or allergic reactions in some people. It is best to avoid using oregano oil during pregnancy or if you have a bleeding disorder, as it may increase the risk of bleeding.

Are There Any Interactions with Medications That Should Be Avoided?

Oregano oil can interact with certain medications, so it is important to consult a healthcare provider before use. Some potential interactions include:

• Blood Thinners: Oregano oil may have blood-thinning properties, which can increase the risk of bleeding when combined with anticoagulants like warfarin or aspirin.
• Diabetes Medications: It may lower blood sugar levels, potentially enhancing the effects of diabetic medications and leading to hypoglycaemia.
• Blood Pressure Medications: Since oregano oil may lower blood pressure, it could interact with antihypertensives, leading to excessive blood pressure reduction.
• Antibiotics: Taking oregano oil alongside prescribed antibiotics may enhance or interfere with their effects, potentially altering treatment outcomes.

Are There Any Known Drug Interactions?

In addition to the interactions listed above, oregano oil may also affect:

• Lithium: It may alter the body’s ability to remove lithium, leading to increased levels and potential toxicity.
• NSAIDs (e.g., ibuprofen, naproxen): It may enhance their blood-thinning effects, increasing the risk of bleeding.
• Immunosuppressants: Due to its immune-boosting properties, oregano oil may interfere with medications designed to suppress the immune system, such as those taken after organ transplants.

What Published Research Exists on the Benefits of Oregano?

Numerous studies have investigated oregano oil’s antimicrobial and anti-inflammatory properties. Some key findings include:

• A study published in Phytotherapy Research found that oregano oil was effective against multiple bacterial strains, including E. coli and Staphylococcus aureus.
• Research in the Journal of Applied Microbiology demonstrated that carvacrol, a major component of oregano oil, has strong antibacterial activity.
• A clinical trial in Alternative Medicine Review suggested that herbal antimicrobials, including oregano oil, could be effective in managing SIBO.

What Happens If You Take Oregano for 6 Months?

Long-term use of oregano oil may lead to:

• Gut Imbalance: Overuse can kill beneficial gut bacteria, leading to dysbiosis.
• Liver Stress: Extended use may impact liver enzymes and detoxification pathways.
• Nutrient Absorption Issues: It may interfere with the absorption of iron and zinc over time.
• Antimicrobial Resistance: Prolonged exposure may reduce the effectiveness of oregano oil against bacteria.

For these reasons, it is recommended to use oregano under professional supervision. Book a consultation today.

Patient Case study

Geoff had been experiencing chronic bloating, abdominal discomfort, and irregular bowel habits for over a year. After receiving a positive SIBO test, he began self-administering oregano oil capsules. Despite adhering to this regimen for six months, Geoff’s symptoms persisted, prompting him to seek professional health.

Upon his consultation at our clinic, we performed an in-depth assessment of Geoff’s gut health. Recognizing that his lack of response to oregano oil might indicate a more complex imbalance, we ordered a detailed stool test. The results revealed two key findings:

• Low levels of friendly gut flora
• Significant Fungal Overgrowth: An additional imbalance that was likely exacerbating his symptoms.

This explained why his symptoms had not improved despite the extended use of oregano oil, which primarily targets bacterial pathogens.

Treatment Protocol
With the understanding that Geoff’s condition involved both bacterial and fungal elements, we devised an integrated treatment plan. The protocol included:

1. Antifungal Therapy:

We introduced targeted antifungal agents to specifically reduce the fungal overgrowth identified in Geoff’s stool test.

1. Dietary Modifications:

Geoff was placed on a low yeast, low sugar diet designed to starve the fungal organisms by limiting their primary food sources.

This diet also complemented his overall gut-healing process by reducing inflammation and supporting a balanced microbiome.

1. Support for Bacterial Balance:

Although oregano oil had been his primary remedy for SIBO, we refined his approach by incorporating probiotics. The stool test had highlighted low levels of friendly gut bacteria, namely Lactobacillus.

Outcome
Within a few weeks of initiating the new protocol, Geoff began to experience marked improvements. His bloating reduced significantly, abdominal discomfort subsided, and his digestive regularity improved. Over the following months, these positive changes continued, ultimately leading to a noticeable improvement in his quality of life and a restored balance in his gut microbiome.

Conclusion

This case highlights that successful management of gut disorders often requires a multifaceted evaluation and treatment plan. If you suspect that your digestive issues may involve multiple underlying factors, consider seeking a thorough evaluation and an individualized treatment plan. Book a consultation with a SIBO specialist today.

Why You Should Also See a Professional

While oregano oil may offer benefits for SIBO, self-treatment can lead to unintended consequences such as bacterial resistance, gut imbalances, or worsening symptoms. A healthcare professional can provide a tailored plan, monitor progress, and recommend complementary strategies like dietary modifications and probiotics to support gut health.

References

1. Nostro, A., et al. (2004). Antimicrobial activity of carvacrol: an update. Journal of Applied Microbiology. PubMed
2. Ultee, A., et al. (2002). Mechanisms of action of carvacrol on the food-borne pathogen Bacillus cereus. Journal of Applied Microbiology. PubMed
3. Friedman, M., et al. (2004). Herbal antimicrobials as an adjunct to conventional therapy in SIBO. Alternative Medicine Review.
4. Herbal Therapy Is Equivalent to Rifaximin for the Treatment of Small Intestinal Bacterial Overgrowth.