Cinnamon: more than just a spice?

By Ana Espino | Published on December 12, 2025 | 3 min read


Cinnamon essential oil, extracted mainly from Cinnamomum zeylanicum and Cinnamomum cassia, has been used for centuries for its medicinal properties. This substance is rich in bioactive compounds, notably cinnamaldehyde, eugenol, and linalool, which give it antimicrobial, antioxidant, anti-inflammatory, and metabolic properties.  

However, despite growing interest in phytotherapy, the clinical use of cinnamon oil remains limited due to the lack of robust clinical studies, variations in its composition depending on botanical origin, and concerns regarding its potential toxicity at high doses.

In this context, this study was initiated to synthesize available data on its pharmacological properties, with the aim of evaluating its potential as a natural therapeutic agent.    

What does science tell us about its real effects?  

 This study is based on selected experimental and preclinical trials that have analyzed the biological effects of cinnamon essential oil. The included works explore its pharmacological properties through in vitro and in vivo models, particularly its antimicrobial, antioxidant, anti-inflammatory, metabolic, and cytotoxic activities. While most of the data come from basic research, some preliminary clinical trials were included when available, in order to broaden the understanding of its therapeutic potential.  

The compiled data show that this oil has significant activity against a wide range of bacteria (including E. coli, Staphylococcus aureus, Listeria monocytogenes) and pathogenic fungi (Candida spp., Aspergillus spp.). It also acts as an antioxidant by reducing oxidative damage to cells, and as an anti-inflammatory agent by inhibiting the production of pro-inflammatory cytokines (notably TNF-α, IL-1β, IL-6). Other studies highlight potential benefits in blood glucose regulation, prevention of diabetes complications, and reduction of blood lipid levels.  

However, human clinical data remain scarce, and most results come from animal or cellular models. Adverse effects, particularly dermatological or hepatic, have been reported at high doses or with prolonged use.  

Promising potential… but still a long way to go  

More and more patients today turn to so-called “natural” therapeutic solutions, seeking alternatives perceived as gentler and better tolerated. In this context, cinnamon essential oil is attracting increasing interest for its numerous biological properties. It indeed shows promising therapeutic potential in several fields, particularly infections, inflammation, diabetes, and oxidative stress.  

However, its use remains limited by several factors. Most of the available evidence is still based on in vitro or animal studies, with few solid clinical data confirming its efficacy and safety in humans. The main challenge, therefore, is to confirm these effects under real clinical conditions, define precise indications, determine optimal dosing, and assess potential long-term adverse effects.  
 
It is with this aim that this review was conducted—to gather current knowledge on the pharmacological properties of cinnamon oil and evaluate its potential as a natural therapeutic agent. The compiled findings highlight interesting biological effects driven by active compounds such as cinnamaldehyde and eugenol, yet call for caution when extrapolating these results to clinical practice. For cinnamon essential oil to find a regulated place in modern pharmacopoeia, rigorous clinical research, standardization of its composition, and better assessment of its toxicological profile are essential. 

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