Oil of oregano (OO) is a concentrated herbal supplement derived from the wild oregano plant, Origanum vulgare. It is popular as a digestive aid and for supporting the immune system. The belief that oregano oil can influence the timing or flow of a period stems from centuries of traditional herbal practice. This article explores the scientific basis for these claims and provides information on the safety of consuming oregano oil.
Active Compounds in Oregano Oil
Oregano oil’s powerful biological effects are primarily due to its high concentration of phenolic compounds, specifically Carvacrol and Thymol. Carvacrol is the most abundant component, often making up 60% to 85% of the oil, with Thymol also present in significant amounts. These compounds are responsible for the oil’s well-documented antimicrobial and antioxidant properties.
These phenols interact with various bodily systems, including those involving smooth muscle tissue. Studies have shown that Thymol can exert a spasmolytic, or antispasmodic, effect on smooth muscles, such as those found in the gastrointestinal tract. This action often involves modulating calcium channels, which initiate muscle contractions.
Traditional Claims of Menstrual Regulation
The idea that oregano can influence menstruation is rooted in centuries of herbal tradition. Historically, oregano and related herbs have been classified as “emmenagogues,” substances believed to stimulate or promote menstrual flow. These traditional uses suggest the herb was taken to encourage menses delayed for reasons other than pregnancy.
Traditional herbalists suggested the mechanism involves stimulating blood flow to the pelvic region and the uterus. This promotion of blood circulation was thought to help induce the period. The use of oregano oil to regulate menstrual cycles or help with painful periods is a common anecdotal claim found in folk medicine.
These traditional claims are based on historical observation, not rigorous scientific testing. Highly concentrated substances like essential oils, when used as emmenagogues, have historically been associated with serious risks, especially when consumed in large doses.
Scientific Understanding of Uterine Effects
Scientific investigation into oregano oil’s specific effects on the human menstrual cycle is extremely limited. There is a lack of large-scale, controlled clinical trials, meaning the direct link between consuming the oil and a measurable change in menstrual timing or flow remains unproven. This creates a significant gap between traditional use and current scientific evidence.
Some laboratory studies have explored the effects of its components on smooth muscle contraction, which is relevant because the uterus is a muscular organ. One study examining Thymol demonstrated its ability to reduce contractions in isolated uterine smooth muscle tissue. This antispasmodic effect suggests a potential mechanism for relieving menstrual cramps, which are caused by uterine contractions.
The general pharmacological properties of oregano oil also suggest a potential for hormonal interaction, as some in vitro studies indicate a weak estrogen-like activity. This hormonal influence could theoretically affect the menstrual cycle. However, current scientific data does not validate traditional claims of menstrual induction at typical supplemental doses.
Safe Consumption and Important Warnings
The high concentration of active compounds, particularly Carvacrol and Thymol, can cause gastrointestinal distress, such as nausea or stomach upset. This occurs especially when the oil is taken in excessive amounts or without dilution. People with known allergies to other plants in the Lamiaceae family, such as mint, basil, or sage, may also experience allergic reactions.
A significant warning pertains to potential drug interactions, particularly with blood-thinning medications like warfarin or heparin. Oregano oil may increase the risk of bleeding due to its potential effect on blood clotting mechanisms. It may also affect blood sugar levels, requiring caution for individuals taking diabetes medications.
Crucially, women who are pregnant must avoid consuming oregano oil in medicinal doses. The traditional use of oregano as an emmenagogue, which stimulates blood flow to the uterus, is the basis for this warning, as it could pose a risk of uterine stimulation or miscarriage. Due to the lack of comprehensive safety data, both oral and topical use is strongly discouraged during pregnancy. Consulting a healthcare provider before starting any new supplement is always the most prudent course of action.