Here's the catch: research suggests lemongrass oil has real antibacterial and anti-inflammatory potential. But a few drops dropped into a glass of water at home is not the same thing as a clinically tested mouthwash, and it's definitely not a substitute for your dentist.
This article walks through what the studies actually found, how lemongrass stacks up against other rinses, and how to use it safely if you decide to try it.
Key Takeaways
- Small clinical trials show early antimicrobial and anti-inflammatory signals for lemongrass oil, not a confirmed treatment
- Mixing drops into water at home isn't a measured dose — oil and water separate, and swishing undiluted oil can irritate tissue
- Lemongrass rinses work best alongside brushing, flossing, and regular dental visits, never as a replacement for them
- Judge any commercial rinse by its full ingredient list, concentration data, and the clinical research behind the finished product
What Is Lemongrass Oil Mouthwash?
Lemongrass essential oil comes from Cymbopogon citratus and Cymbopogon flexuosus, extracted through steam or hydrodistillation. Different species yield chemically different oils, so one bottle labeled "lemongrass" isn't automatically identical to another.
The compound researchers care most about is citral, a mix of two isomers called geranial and neral. Depending on the plant and extraction method, citral can make up roughly 65–85% of the oil, and lab studies link it to antimicrobial and anti-inflammatory activity.
Ready-Made Rinse vs. Homemade Dilution
A manufactured lemongrass mouthwash and a homemade drop-in-water version aren't interchangeable:
- Commercial products use measured concentrations, dispersing agents to keep oil and water mixed, preservatives, and pH balancing
- Homemade mixes rely on guesswork : oil floats and separates, so one swish might be mild and the next too strong
- Quality control (batch testing, labeling, expiration dates) exists for finished products but not for a DIY jar on your bathroom counter
Natural Doesn't Mean Risk-Free
Essential oils are concentrated plant extracts, meant to be diluted and spit out, not swallowed. "Natural" describes the source, not the safety profile.
This article focuses on what lemongrass rinses can reasonably help with: bad breath, surface plaque, and mild gum inflammation. Periodontitis, cavities, abscesses, and oral lesions that won't heal all require a dentist's evaluation, not a rinse.
What Does the Research Say About Lemongrass Oil Mouthwash?
The evidence here is real but narrow. It points to short-term, formulation-specific benefits, not proof that lemongrass prevents gum disease long-term.
The 0.25% Lemongrass Trial
The most-cited study is a 2015 parallel-arm trial of 60 adults with mild-to-moderate gingivitis, split into three groups: 0.25% lemongrass oil mouthwash, 0.2% chlorhexidine, and mechanical care alone (brushing and professional cleaning, no rinse). Participants rinsed twice daily for one minute over 21 days.
Both rinse groups improved more than the no-rinse group on plaque and gingival index scores at days 14 and 21. But the difference between lemongrass and chlorhexidine wasn't statistically significant, according to a 2015 clinical trial. That's a meaningful result, but with only 20 people per arm and three weeks of follow-up, it's a preliminary signal, not proof of equivalence.
Bacteria, Biofilm, and Breath Are Separate Questions
Lab and pilot studies have looked at lemongrass from different angles:
- Oral bacteria: Lab testing found activity against P. gingivalis and A. actinomycetemcomitans, with weaker effects on S. mutans (the main cavity-causing bacteria)
- Breath: A small pilot study of 20 healthy volunteers found reduced volatile sulfur compounds by day 8, though taste needed improvement
- Candida biofilm: A lab study on silicone discs (not human mouths) found a 5% oil concentration reduced fungal biofilm by about 95% (a concentration far too strong for rinsing)
A bacteria culture shrinking in a lab dish doesn't automatically mean less plaque in your mouth. These are different endpoints, and mixing them up overstates what's actually been shown.
Inflammation Claims Need Context
A separate 45-person, three-month study measured gum pocket depth and a blood marker called CRP (C-reactive protein) in people with severe periodontitis. Both lemongrass and chlorhexidine groups showed improvement over mechanical care alone.
A related study tested a 2% lemongrass gel (not mouthwash) placed directly into gum pockets alongside scaling and root planing, with results comparable to a 10% doxycycline gel, except plaque reduction wasn't statistically significant. Gel results don't transfer automatically to a rinse; delivery method matters.
Where the Evidence Falls Short
- Studies are small (typically 20–60 participants) and short (three weeks to three months)
- Formulations vary widely, so results from one concentration don't apply to another
- No long-term daily-use safety or efficacy data exists
- A 2024 scoping review found just eight clinical studies overall, with inconsistent designs and incomplete randomization reporting
How Does Lemongrass Oil Mouthwash Compare With Other Options?
Choosing a rinse comes down to matching the product to your actual goal, not picking whatever sounds most natural.
| Rinse Type | Best For | Evidence Strength | Key Caution |
|---|---|---|---|
| Lemongrass oil | Adjunctive plaque/gum support | Small, short-term trials | Formulation-dependent; not standardized |
| Chlorhexidine | Short-term professional gingivitis control | Large evidence base (51 studies, 5,345+ participants) | Staining, taste changes with extended use |
| CPC rinses | Daily plaque and gingivitis maintenance | Established, concentration-dependent | Effects vary below 0.05% concentration |
| Saltwater | Post-extraction comfort | Supportive, procedure-specific | Not a substitute for antimicrobial rinsing |
| Alcohol-free blends | Dry mouth or irritation sensitivity | Depends on active ingredients | "Alcohol-free" ≠ proven effective |
Why Alcohol-Free and Chlorhexidine Aren't Interchangeable
People with dry mouth or burning sensations often do better with alcohol-free formulas, since alcohol itself can worsen dryness. Chlorhexidine, by contrast, is typically prescribed for defined short-term situations, carries staining risk with prolonged use, and isn't meant for indefinite daily use. The ADA's mouthrinse guidance treats these as distinct tools for distinct problems, not competing versions of the same product.
Saltwater rinses have their place too : mainly as gentle, temporary aftercare following procedures like extractions. They're not a replacement for a formulated antimicrobial rinse, and no rinse of any kind replaces mechanical plaque removal from brushing and flossing.
A Formulated Alternative Worth Knowing About
If the appeal of lemongrass is really "gentle and alcohol-free," it's worth knowing that's not the only route there. Gengyve, developed by practicing oral and maxillofacial surgeons, is a fluoride-free, chlorhexidine-free daily rinse built around cetylpyridinium chloride (CPC) and hyaluronic acid rather than lemongrass oil. A published 21-day trial on the formulation involving 75 dental students reported improvements in gum health markers , worth reviewing on its own terms rather than assuming it shares a mechanism with essential-oil rinses. Check any product's current label and research summary before comparing it to lemongrass.
How to Choose and Use Lemongrass Oil Mouthwash Safely
Reading a Commercial Label
Before buying, check that the product discloses:
- Active ingredient(s) and concentration or formulation details
- Directions for frequency and swish time
- Expiration date and manufacturer contact information
- Warnings about irritation or accidental swallowing
Why Homemade Recipes Are Risky to Standardize
A recipe that says "add a few drops of lemongrass oil to water" sounds simple, but it isn't reproducible. Drop size varies by dropper, oil floats on top of water instead of blending in, and the dose you actually swish could be far stronger (or weaker) than anything tested in a study. Treat any homemade version as a general safety example, never a proven treatment.
Using It Safely
- Follow the label exactly: don't eyeball concentrations
- Measure, don't guess, if a recipe is used at all
- Swish only for the directed time, then spit it out
- Never swallow essential oil-based rinses
- Stop immediately if burning, stinging, or irritation develops
Undiluted essential oil swallowed accidentally can cause throat irritation, coughing, or choking, according to Poison Control. If that happens, contact Poison Control at 1-800-222-1222.
Who Should Check With a Dentist First
- Children (swallowing risk is higher, and dosing isn't established for them)
- Anyone with known essential-oil allergies or sensitivities
- People with asthma or other respiratory conditions
- Pregnant or breastfeeding individuals
- Anyone recovering from oral surgery or undergoing cancer treatment
Signs You Need Professional Care, Not Just a Rinse
See a dentist promptly for:
- Persistent bleeding or swelling that doesn't improve
- Pus, loose teeth, or a fever
- Severe pain
- Mouth ulcers that haven't healed within two weeks
- Symptoms that continue despite consistent brushing and flossing
No mouthwash, lemongrass or otherwise, replaces the fundamentals: brushing twice daily with fluoride toothpaste, cleaning between teeth daily, limiting frequent sugary or acidic snacking, and keeping regular dental checkups.
Frequently Asked Questions
What essential oil kills bacteria in the mouth?
Several oils, including lemongrass, thymol, and eugenol, have shown antimicrobial activity in lab and limited clinical studies. None should be described as eliminating all oral bacteria . Formulation, dilution, and professional guidance all matter.
Is lemongrass oil mouthwash good for gingivitis?
Small studies show short-term improvements in plaque and gum inflammation scores comparable to chlorhexidine. It may support oral hygiene, but it can't replace a dentist's diagnosis or treatment plan.
How do you make lemongrass oil mouthwash?
Household recipes aren't standardized : drop counts vary, and oil doesn't mix evenly with water. Undiluted oil should never go in your mouth, and a properly labeled, formulated product is generally easier to dose safely.
Is lemongrass essential oil safe to use in the mouth?
Only when properly diluted, spit out rather than swallowed, and discontinued at the first sign of irritation or allergic reaction. Children and medically vulnerable individuals need extra caution and a dentist's input first.
Can lemongrass mouthwash replace brushing and flossing?
No. Mouthwash can't mechanically remove plaque the way brushing and interdental cleaning can. It works only as an addition to, never a substitute for, a full oral hygiene routine.
Is lemongrass oil better than chlorhexidine mouthwash?
They serve different purposes with very different evidence bases. Chlorhexidine is typically reserved for specific short-term clinical situations under professional guidance, so the right choice depends on your dentist's recommendation, not a self-directed swap.
