Lemongrass essential oil is primarily used for its antimicrobial properties, its ability to reduce inflammation and pain, and its role as a natural insect repellent. Its main active compound, citral, gives the oil both its sharp citrus scent and most of its biological activity. Here’s what the evidence actually supports.
Key Active Compounds
The oil is extracted from the leaves and stalks of lemongrass (Cymbopogon citratus) through steam distillation. Its dominant compound is citral, which typically makes up 60 to 80 percent of the oil. Geraniol, another active component, plays a significant role in several of the oil’s benefits, particularly for digestive health. The plant also contains flavonoids and polysaccharides that contribute antioxidant effects, though these are more concentrated in lemongrass tea and extracts than in the essential oil itself.
Antimicrobial Effects
Lemongrass oil has been tested against a broad range of pathogens: at least 42 microorganisms in one review alone, including 20 bacteria, 15 fungi, and 7 yeasts. It works by destabilizing the outer membrane of bacterial cells, essentially puncturing their protective layer and shutting down their internal processes. This makes it effective against both major classes of bacteria.
Specific organisms it inhibits include E. coli, Staph aureus, Salmonella, Klebsiella pneumoniae, and Candida albicans (a common cause of yeast infections). Lab imaging has shown it can completely disfigure certain bacterial cells, and it also breaks down biofilms, the sticky colonies bacteria form on surfaces that make them harder to kill.
There’s also preliminary antiviral evidence. The oil has shown activity against herpes simplex virus type 1 and murine norovirus in lab settings, and lemongrass compounds inhibited tobacco mosaic virus by more than 50 percent at tested concentrations. These are lab results, not clinical treatments, but they suggest the oil’s antimicrobial reach extends beyond bacteria and fungi.
In practical terms, this makes lemongrass oil useful in natural cleaning products, surface disinfectants, and food preservation. It’s not a replacement for antibiotics or antifungal medications for active infections, but its broad-spectrum activity explains why it shows up in so many natural household products.
Pain and Inflammation Relief
Citral, the oil’s primary compound, has demonstrated meaningful anti-inflammatory activity. In a small study of 30 people with rheumatoid arthritis, participants applied 3 milliliters of lemongrass oil daily for 30 days. Their average pain scores dropped from 8 out of 10 to 5 out of 10, a reduction of roughly 37 percent. Pain was measured every two days throughout the study, showing a gradual decline rather than an immediate effect.
The anti-inflammatory mechanism appears to involve citral suppressing the body’s inflammatory signaling pathways. Lemongrass oil has been ranked among the top six essential oils for anti-inflammatory properties in comparative research. For topical pain relief, it’s typically diluted in a carrier oil and massaged into sore joints or muscles. The effect builds over consistent use rather than providing instant relief like a conventional painkiller.
Stomach and Digestive Support
Animal research has shown that lemongrass oil can both prevent and help heal stomach ulcers through two distinct mechanisms. The oil reduced ulcer area by about 52 percent in ethanol-induced ulcers at a low oral dose. Citral alone was even more potent for prevention, reducing ulcer area by nearly 97 percent, though at a higher dose.
The healing story is more nuanced. When it comes to repairing existing ulcers, the oil and its geraniol component accelerated healing by 35 and 81 percent respectively, confirmed by microscopic examination showing the ulcer base contracting and mucus production increasing. Citral, surprisingly, did not promote healing on its own despite being effective at prevention. The oil also inhibited the stomach’s acid-producing enzyme by about 28 percent, which helps explain part of its protective effect.
These findings come from mouse studies, so the doses don’t translate directly to human use. But they do support the traditional use of lemongrass tea for stomach complaints and suggest the oil’s digestive benefits come from multiple compounds working together rather than citral alone.
Antioxidant Properties
Lemongrass contains several compounds that neutralize free radicals, the unstable molecules that damage cells and contribute to aging and chronic disease. Lab testing found that some of its flavonoid compounds matched quercetin, a well-known antioxidant used as a research benchmark, in free radical scavenging ability. Isoorientin and caffeic acid, two compounds found in lemongrass, had near-identical potency to quercetin in standard antioxidant assays.
These antioxidant compounds are more abundant in lemongrass tea and whole-plant extracts than in the distilled essential oil, which is richer in volatile compounds like citral. If antioxidant benefits are your primary goal, drinking lemongrass tea likely delivers more of these protective flavonoids than inhaling or applying the oil.
Insect Repellent Use
Lemongrass oil is one of the most common ingredients in plant-based insect repellents, but its protection time is significantly shorter than synthetic alternatives. A University of Florida evaluation found that a repellent containing 1 percent lemongrass oil (alongside citronella and other plant oils) provided only about 19 minutes of mosquito protection. For comparison, a product with 23.8 percent DEET lasted 5 hours, and even a children’s formula with 4.75 percent DEET provided 1.5 hours of protection.
This means lemongrass-based repellents require frequent reapplication to remain effective. They can work for short outdoor activities like a quick garden session, but they’re not practical choices for hiking, camping, or spending extended time in mosquito-heavy areas. If you prefer a natural option, plan to reapply every 15 to 20 minutes.
Aromatherapy and Mood
Lemongrass oil is widely used in diffusers for its energizing, citrus-forward scent. It’s commonly promoted for reducing anxiety and stress, and clinical trials are currently underway measuring whether inhaling lemongrass oil lowers salivary cortisol (the body’s primary stress hormone) and heart rate in anxiety-inducing situations like dental procedures. Results from these trials aren’t available yet, so the calming effects remain anecdotal rather than clinically confirmed.
What most users report is that the scent feels clarifying and uplifting rather than deeply sedating. If you’re choosing between lemongrass and lavender for relaxation, lavender has a much stronger evidence base for reducing anxiety. Lemongrass may be better suited as a daytime or focus-oriented aromatherapy option.
Safe Use on Skin
Lemongrass oil is one of the more irritating essential oils for skin, and the maximum recommended dilution for topical use is just 0.7 percent. That’s roughly 4 drops of essential oil per ounce of carrier oil. This limit applies regardless of where on the body you’re using it, because the concern is skin sensitization, an allergic-type reaction that can develop from repeated exposure to higher concentrations.
Always dilute lemongrass oil in a carrier oil like coconut, jojoba, or sweet almond oil before applying it to skin. If you’re using it in a diffuser, standard guidance is 3 to 5 drops per 100 milliliters of water. Avoid applying it near your eyes or on broken skin, and do a small patch test on your inner forearm before using it on larger areas, especially if you have sensitive skin or a history of contact allergies.