Oil of Oregano

Oil of oregano is a plant that belongs to the mint family. Two major extracts contained in oil of oregano are carvacrol and thymol. Carvacrol is a phenol antioxidant and thymol is a plant (also thought to be an antioxidant) that may have properties to help against toxins and fungal infections. Antioxidants help reduce oxidation and free radicals that can cause damage to cells.

The correlation of SIBO and Oil of Oregano

A small study involved a group of patients with a condition called small intestinal bacterial overgrowth (SIBO) were offered an herbal product or antibiotics. Oil of oregano was one of the several herbals involved in the study. The researchers concluded that the herbals utilized were as effective as antibiotics. However, these results were only positive for a handful of patients (17 patients within the study) and therefore much larger studies are needed before concluding that oil of oregano is effective for SIBO.

Benefits of Oil of Oregano

Oil of oregano is thought to help ease gastrointestinal illnesses, as well as respiratory illnesses.  Benefits for bacterial infections have been demonstrated in mouse studies, however they have not been replicated in humans. One published study in mice concluded that oil of oregano was beneficial in prevention or treatment of staphylococcus aureus. Another study in mice demonstrated that oil of oregano was effective in destroying bacteria in dysentery (inflammation of the intestines accompanied by bloody diarrhea). Again, these studies were not done in humans and more studies are needed.

Oil of Oregano should be avoided among the following:

  1. People with allergic reaction to plants in the Lamiacea family. This includes basil, mint, rosemary, sage, savory, marjoram, oregano, hyssop, thyme, perilla
  2. Avoid in pregnancy as there is concern of miscarriage
  3. Bleeding disorders as it may increase the risk of bleeding. Discontinue use two weeks before scheduled surgery due to concerns over bleeding risk
  4. Caution with diabetes as blood sugar levels may be increased

Mild side effects may include stomach upset and irritation of the intestinal tract.

Medications may interact with Oil of Oregano including: Antidiabetic drugs (may decrease blood sugar), other herbs that may lower blood sugar (alpha lipoic acid, chromium, psyllium), anticoagulants (avoid with garlic, ginger and gingko).

When taken with copper, iron, or zinc it may decrease it’s absorption.

If you are interested in learning more about Oil of Oregano stop by and talk to our pharmacist. Always talk to your pharmacist and provider prior to supplementing.



  1. https://www.ncbi.nlm.nih.gov/pubmed/15587409. Accessed on March 24, 2020
  2. https://doi.org/10.1080/15376520590968833. Accessed on March 24, 2020
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4030608/. Accessed on March 24, 2020