Oregano - Rezulin (Troglitazone) Interaction
Herbal: Oregano
Also Known As: Origanum vulgare, Carvacrol, European Oregano, Marjolaine Sauvage, Marjolaine Vivace, Mediterranean Oregano, Mountain Mint, Oil of Oregano, Oregano Oil, Organy, Origan, Origan Européen, Origani Vulgaris Herba, Origano, Winter Marjoram, Wintersweet
Drug: Troglitazone
Brand names:
Rezulin

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Troglitazone is classified as belonging to the following category: Antidiabetes Drugs
Theoretically, oregano might increase the risk for hypoglycemia when taken with antidiabetes drugs.
In vitro and animal research shows that oregano extracts might lower blood glucose levels.
Interaction Rating
Likelihood of Occurrence
PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Pharmacist Analysis
Several studies suggest that oregano supplements may help lower blood glucose (i.e., sugar) levels. In vitro and animal research has shown that oregano extracts might stimulate glucose uptake and reduce blood glucose levels.
For example, a study on diabetic rats found that oregano oil significantly decreased blood glucose levels, increased insulin levels, and improved glucose tolerance.
Therefore, based on the available evidence, combining oregano oil with antidiabetic drugs could potentially cause blood sugar levels to drop too low, leading to hypoglycemia.
However, it is important to note that studies reporting that oregano can reduce blood glucose levels have not reported it causing hypoglycemia.
Nevertheless, a theoretical interaction remains here due to the potential additive blood-sugar-lowering effects of oregano and certain antidiabetic drugs.
It should be noted that some drugs may be riskier than others.
A drug like metformin, a very commonly used oral drug for diabetes, has a very low risk of hypoglycemia, and combining it with oregano wouldn't generally be considered dangerous.
Other drugs, like insulin and sulfonylureas, (e.g., glipizide), carry a higher risk of hypoglycemia and may put you more at risk of your blood sugar dropping too low if you take oregano. It's certainly possible dosage adjuments may be needed if oregano is combined with them.
Be sure to talk to your doctor and don't make any changes to your medication regimen before doing so.
- Dr. Brian Staiger, PharmDReferences
- Lemhadri, A., Zeggwagh, N. A., Maghrani, M., Jouad, H., and Eddouks, M. Anti-hyperglycaemic activity of the aqueous extract of Origanum vulgare growing wild in Tafilalet region. J Ethnopharmacol. 2004;92(2-3):251-256.
- McCue, P., Vattem, D., and Shetty, K. Inhibitory effect of clonal oregano extracts against porcine pancreatic amylase in vitro. Asia Pac.J Clin.Nutr. 2004;13(4):401-408.
- Silva MLAE, Lucarini R, Dos Santos FF, et al. Hypoglycemic effect of rosmarinic acid-rich infusion (RosCE) from Origanum vulgare in alloxan-induced diabetic rats. Nat Prod Res 2022;36(17):4525-4531.
Oregano Overview

Oregano - More Interactions
Oregano interacts with 205 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
Unknown | No interactions have been reported or no interaction data is currently available. |
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DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
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