Serai:
The Plant That
Smells Like
Home to Bees
— and Does
What Antibiotics
Cannot.
It is in every Malaysian kitchen. It is in every Malay dish you have ever loved. It is in the air of every kampung. And it is being studied right now as a compound that makes cancer cells self-destruct while leaving healthy cells completely alone. You have been walking past a laboratory every day of your life.
Honeybees use lemongrass to call their swarm home.
The compound that gives lemongrass its distinctive smell is called citral. It makes up 65 to 80 percent of lemongrass essential oil. And citral is one of the seven chemical components of the Nasonov pheromone — the chemical signal honeybees produce from a gland in their abdomen to call a lost swarm back to the hive.
When a swarm leaves a colony, scout bees stand at the entrance of the new home with their abdomens raised, fanning their wings, releasing the Nasonov blend into the air. The swarm follows the scent. The scent is, in significant part, lemongrass.
This is why beekeepers around the world put drops of lemongrass essential oil in empty hive boxes to attract wild swarms. The bee smells the lemongrass and responds as if it has found home.
The same compound — citral — is what kills cancer cells in laboratory research. What guides honeybee societies. What you smell in your rendang. What has been used in traditional medicine across Asia for thousands of years.
One molecule. Many worlds.
Serai — What It Actually Is
Lemongrass. Cymbopogon citratus. A grass. Not a shrub, not a tree, not a flowering herb in the conventional sense. A tropical grass that grows in dense clumps up to two metres tall, with long flat blades and a distinctive white-to-purple base where the stalk thickens into the portion used in cooking.
Its name in Malay is serai. It is native to maritime Southeast Asia — to the region of Malaysia, Indonesia, Brunei, and the Philippines. This is not an imported plant. This is ours. It came from here. The cuisine of this region was built around it for a reason.
There are 55 species in the Cymbopogon genus. The one used in Malaysian cooking and traditional medicine is Cymbopogon citratus — West Indian lemongrass, as botanists call it, despite it being native to Southeast Asia. The East Indian variety (Cymbopogon flexuosus) is used more for essential oil production. They can be used interchangeably, but for the kitchen and for the tea, serai makan — C. citratus — is what matters here.
Core ingredient in rendang, laksa, satay, tom yam, and the daily masakan Melayu. Present in almost every savoury dish in the Malaysian kitchen.
Central to Thai cuisine. In tom kha and tom yam soups it provides the base aromatic note that defines the dish.
Sanskrit texts called it the “aromatic grass” and prescribed it for digestive complaints, fever, and as a nervine tonic. Documented in classical Ayurvedic texts.
Used in Traditional Chinese Medicine for pain, fever, digestive disorders and as a warming herb for cold conditions. Documented in the Chinese Materia Medica.
One of the most widely consumed medicinal teas in Brazil, taken for anxiety and digestive problems. Despite widespread traditional use, human trials showed limited efficacy for anxiety at tea concentrations.
Across Nigeria, Ghana, Cameroon and the wider region, lemongrass tea has been the traditional first response to fever for generations. One of its most consistent traditional applications across multiple continents.
The Grass That Every Civilisation It Met Decided to Keep
Lemongrass is native to maritime Southeast Asia. Long before any documentation, the communities of what is now Malaysia, Indonesia, and the Philippines were using serai as food, flavouring, and medicine. The Orang Asli and the proto-Malay peoples built their food systems around plants that were available, effective, and safe across generations. Lemongrass was among them — not because it was exotic or special, but because it was ubiquitous and consistently useful.
Classical Ayurvedic medicine documented lemongrass (Bhustrina) as a treatment for fever, digestive disturbances, and as a nervine — a herb that supports the nervous system. It was classified as diaphoretic (promoting perspiration), carminative (relieving gas), and antipyretic (reducing fever). The precision of the Ayurvedic classification reflects centuries of clinical observation before the term “clinical” existed.
The Chinese pharmacopoeia documented lemongrass as a warming herb used for pain in the lower abdomen, cold conditions, and digestive disruption. TCM classified it by its thermal properties — warming — and its action on specific organ meridians. When modern research confirmed lemongrass’s anti-inflammatory and antispasmodic properties through molecular analysis, it was arriving at conclusions the Chinese system had reached through a completely different methodology, centuries earlier.
When European botanists documented the plants of Southeast Asia and India during the colonial period, they found lemongrass already in sophisticated medicinal use across multiple distinct traditional systems. It was being used for fever, digestion, pain, skin conditions, and as a general tonic — independently, across cultures that had no contact with each other, for the same core applications. The convergence of unconnected traditions on the same plant for the same purposes is the most reliable signal that a plant works.
Lemongrass is now among the most studied medicinal plants in the world. Research programmes in Brazil, India, Malaysia, the United States, Poland, and Romania are investigating its pharmacological properties. The applications under research include cancer, antibiotic-resistant bacteria, metabolic syndrome, neurological protection, and gut microbiome regulation. The grass that sat in every Malaysian kitchen is sitting in laboratories across four continents.
“When independent civilisations on separate continents, with no contact with each other, reach the same conclusions about the same plant across thousands of years — that is not coincidence. That is accumulated evidence. The longest clinical trial in history.”
Serai — The Herb Your Nenek Never Had to Name as Medicine
In Malaysia, serai was never “alternative medicine.” It was simply cooking.
This is the critical distinction that gets lost when we discuss Malaysian rainforest herbs in a pharmaceutical framework. Serai was not something you reached for when you were sick. It was in the pot every day because the people who put it there understood — not through laboratory analysis but through generations of living — that the food prepared with these ingredients maintained health in a way that food prepared without them did not.
Rendang. Laksa. Satay marinade. Tom yam. Gulai. Soup base. The Malay kitchen did not separate food from medicine. They were the same act. The same ingredients. The same daily practice. The herbs in the masakan were the medicine. The medicine was the masakan.
Serai specifically: boiled into teas for fever and digestive complaints. Added to bathing water for muscle pain and as a postpartum cleansing preparation. Burnt as a natural insect repellent in homes. Planted at the borders of gardens because the smell confuses and deters pests. The applications were not isolated treatments for named conditions. They were a life system in which this particular grass had a dozen different functions, all working simultaneously.
The Orang Asli and Serai
Ethnobotanical surveys of Orang Asli communities across Peninsular Malaysia document lemongrass as part of the traditional plant knowledge of multiple sub-groups — Semai, Temuan, Jah Hut, and Semang communities. It appears in records of medicinal plant use for fever, digestive conditions, and as a topical preparation for skin conditions and joint pain.
What the Orang Asli knew was not named the way a clinical trial is named. They observed that this grass, prepared in specific ways, changed specific conditions in specific people. That knowledge was transmitted not as a formula but as a practice — embedded in daily life, observable across generations, and accurate enough to persist across thousands of years of living in the same forest.
The molecular explanation for why it works was three thousand years away. The observation that it worked was never in doubt.
What 65 to 80% Citral Actually Does
Up to 80% of lemongrass essential oil is citral — the compound that gives it the smell and drives most of its documented pharmacological activity.
One animal study reported a 95% reduction in lymphoma tumour volume following oral administration of lemongrass extract. Without observed toxicity in healthy cells.
Lemongrass essential oil sensitised methicillin-resistant Staphylococcus aureus (MRSA) to the antibiotic methicillin by up to 9.6 times. It breaks down antibiotic resistance.
Five cups of lemongrass tea per day reduced LDL (bad) cholesterol by 11.1% and total cholesterol by 6.5% in a documented study.
Citral is the headline. The full cast is more complex.
Lemongrass essential oil contains citral (65–80%), which itself consists of two geometric isomers: geranial (citral A, the more biologically active form) and neral (citral B). Together they produce the characteristic lemon scent and drive the antibacterial, anti-inflammatory, and anticancer activities.
The supporting compounds include: β-myrcene — a terpene with analgesic and anti-inflammatory properties; limonene — linked to anticancer activity and immune modulation; geraniol — antimicrobial and one of the honeybee Nasonov pheromone components; linalool — documented for anxiolytic and sedative properties; and a range of flavonoids including luteolin, quercetin, kaempferol and isoorientin — each with documented antioxidant and anti-inflammatory mechanisms.
The whole plant extract has repeatedly proven more effective than isolated citral alone. This is the same finding across almost every complex medicinal plant: the compounds work synergistically. Isolating one and discarding the others reduces the effect. The plant’s intelligence is in the combination.
The dominant compound. Antibacterial, antifungal, anti-inflammatory, and the subject of the most significant anticancer research. The same compound honeybees use in their homing pheromone.
Analgesic and muscle-relaxant properties. Enhances the absorption of other terpenes across biological membranes, amplifying the effect of the whole oil. One of the reasons the whole plant outperforms isolated fractions.
The most biologically active class of compounds in lemongrass solid extracts. Anti-inflammatory, antioxidant, and showing anticancer activity across multiple cell lines. Quercetin specifically inhibits pro-inflammatory enzyme pathways.
Antimicrobial across a wide spectrum of bacteria and fungi. One of the seven components of the honeybee Nasonov pheromone. Anti-inflammatory properties documented. Also used in the perfumery industry as a rose-like fragrance component.
A potent antioxidant that protects vascular endothelial cells from oxidative damage. Research documented lemongrass polyphenols protecting human umbilical vein endothelial cells from damage caused by high glucose, hydrogen peroxide, and oxidised LDL.
Anti-inflammatory and antioxidant compound specific to lemongrass. Inhibits NF-κB — the same inflammatory master switch targeted by many pharmaceutical anti-inflammatory drugs. Does so through a different, gentler mechanism than NSAIDs.
Five Areas Where the Science Is Serious
One: Anticancer Activity — The Most Significant Finding
This requires careful framing. The anticancer research on lemongrass is compelling, scientifically rigorous in its methodology, and not yet validated in human clinical trials. Both of those statements are true simultaneously.
What the research shows in laboratory and animal studies is extraordinary. Lemongrass extract induced apoptosis — programmed cell death — in colon cancer cells (HCT-116 and HT-29 cell lines) in a dose and time-dependent manner. The critical finding: it did not harm healthy colon cells in the same experiments. Selective toxicity against cancer cells while sparing normal cells is the property every cancer researcher is trying to find.
In another study, oral administration of lemongrass extract in mice implanted with non-Hodgkin’s lymphoma cells produced a reported 95% reduction in tumour volume over a short period. Without observed weight loss or toxicity.
Lemongrass extract demonstrated activity against colorectal cancer, cervical cancer (HeLa cells), breast cancer, liver cancer, lung cancer, and multiple blood cancer cell lines. In human colorectal cancer models, it enhanced the effectiveness of the standard chemotherapy drug FOLFOX while reducing its side effects.
The mechanism: citral and the whole extract trigger oxidative stress specifically in cancer cells, activate the mitochondrial death pathway, and inhibit the enzyme ALDH1A3 — which cancer stem cells use to resist conventional chemotherapy. The plant may be undermining the resistance mechanism that makes some cancers so difficult to treat.
Research is also confirming that the whole extract outperforms isolated compounds. The synergy of lemongrass’s full phytochemical matrix is more effective against cancer cells than any single compound pulled from it. This is why traditional preparations that use the whole plant are pharmacologically more sophisticated than any supplement that isolates one fraction.
Two: Antibiotic Resistance — Something Pharmaceutical Companies Are Spending Billions to Solve
One of the most important findings in recent lemongrass research is not about what lemongrass kills. It is about what lemongrass breaks.
MRSA — methicillin-resistant Staphylococcus aureus — is one of the most dangerous antibiotic-resistant bacteria in the world. It has developed the ability to resist penicillin-class antibiotics, making standard treatment ineffective. Hospital-acquired MRSA infections kill tens of thousands of people annually.
A peer-reviewed study found that lemongrass essential oil sensitised MRSA to methicillin by up to 9.6 times. The lemongrass oil did not kill the bacteria directly at the concentrations tested. It broke down their resistance mechanism — making them vulnerable again to an antibiotic they had learned to defeat.
The proposed mechanism: inhibition of the P-glycoprotein efflux pump — the molecular mechanism bacteria use to expel antibiotics before they can do damage. The lemongrass compounds blocked the pump. The antibiotic could then do its work.
If this mechanism translates to clinical use, it would represent an entirely different approach to the antibiotic resistance crisis: not developing new antibiotics (which bacteria will eventually also resist), but restoring the effectiveness of existing ones. The grass in the kitchen is being investigated for one of the most serious public health problems of the 21st century.
Three: Blood Sugar and Cholesterol — The Metabolic Profile
Oral treatment of lemongrass aqueous extract at 200mg/kg body weight for 30 days produced a considerable drop in blood sugar levels in animal studies. The proposed mechanism involves alkaloids and flavonoids that promote hypoglycaemic effects through both insulin sensitisation and peripheral glucose consumption enhancement.
On cholesterol: five cups of lemongrass tea per day reduced LDL cholesterol by 11.1% and total cholesterol by 6.5%. Aqueous root and flower extracts of lemongrass significantly lowered total cholesterol in animal studies, with higher HDL and lower LDL — a favourable lipid profile shift. Lemongrass tea promotes the thermogenesis process that reduces plasma cholesterol and facilitates the fecal excretion of cholesterol — one of the more elegant mechanisms for cholesterol management, bypassing the bloodstream entirely.
Four: Anti-Inflammatory — Through Multiple Pathways
Lemongrass inhibits NF-κB, the master inflammatory signalling pathway. This is the same pathway targeted by NSAIDs and corticosteroids — pharmaceutical anti-inflammatories. The difference: lemongrass approaches the pathway through flavonoid modulation rather than enzyme blockade, meaning it modulates inflammation rather than suppressing it indiscriminately.
The antioxidant profile supports this. Methanol extracts of lemongrass demonstrated strong DPPH radical-scavenging activity. The leaves showed the highest antioxidant activity of all plant parts tested. Oxidative stress is the upstream driver of chronic inflammation — address the oxidative stress and the inflammatory cascade loses its fuel.
Five: Antimicrobial — Broad Spectrum, No Resistance Development
Lemongrass essential oil and extracts have demonstrated activity against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans, Aspergillus niger, Aspergillus fumigatus, Salmonella typhi, and a broad spectrum of other bacteria and fungi. The antimicrobial activity is attributed primarily to citral and its disruption of bacterial cell membrane integrity — a physical mechanism, not a biochemical one, which is why resistance development is so much harder to achieve.
Bacteria develop resistance to antibiotics by evolving to chemically neutralise or expel the drug. Developing resistance to a compound that physically disrupts the membrane itself is significantly more difficult. This is why lemongrass’s antimicrobial activity has remained consistent across decades of research while pharmaceutical antibiotics have faced progressively escalating resistance.
What Is True, What Is Exaggerated, and What Is Simply Wrong
“Lemongrass tea calms anxiety and stress.”
Lemongrass is widely promoted as an anxiolytic — a natural treatment for anxiety and stress. This is one of its most ancient and widespread traditional uses, particularly in Brazil where it is among the most consumed medicinal teas for nervous complaints. However, a double-blind clinical trial testing lemongrass tea in human volunteers found no significant anxiolytic effect compared to placebo. The trial specifically tested oral tea at therapeutic concentrations. The researchers concluded that either the dose or the route of administration was insufficient to produce the reported effect. Aromatherapy with lemongrass essential oil has shown more promise in anxiety reduction studies — the inhaled route may deliver compounds differently than the oral route. The claim is not false. The evidence for it at tea concentrations specifically is weaker than the traditional use suggests.
“Lemongrass repels mosquitoes.”
The mosquito-repelling reputation belongs primarily to citronella grass (Cymbopogon nardus and Cymbopogon winterianus) — a close relative of lemongrass, not lemongrass itself. The two are frequently confused because they are in the same genus and both contain citral. Burning lemongrass or applying the oil provides some repellent effect due to the citral content, but the dedicated insect-repelling compound in commercial citronella products comes from citronella grass, which has a much higher citronellal content. Using lemongrass as your primary mosquito defence is less effective than using actual citronella. The confusion is understandable and the plants are related — but they are not the same.
“Drink lemongrass tea and it will detox your body.”
“Detox” is a marketing term, not a physiological process. Your liver and kidneys detoxify continuously, without herbal assistance, as long as they are functioning. What lemongrass does that is real and documented: it has diuretic properties, meaning it increases urinary output. It has antioxidant properties that reduce oxidative stress. It has anti-inflammatory properties that reduce the cellular damage chronic inflammation causes. These are real effects with real mechanisms. They are not “detox.” Attributing them to a vague detox claim understates what the plant actually does, while making an unverifiable promise. Use the real language. The real language is impressive enough.
“Lemongrass essential oil cures cancer — drink a few drops daily.”
The anticancer research on lemongrass is real, peer-reviewed, and genuinely significant. But it is in vitro (cell culture) and in vivo (animal) research. Human clinical trials confirming anticancer efficacy in people have not been conducted. The leap from “kills cancer cells in a petri dish” to “cures cancer if you drink it” is scientifically invalid. Furthermore: lemongrass essential oil in concentrated, undiluted form is toxic. One review noted that in undiluted form it may be toxic or fatal if taken orally in large doses. Citral, the active compound, is chemically fragile and poorly bioavailable in the gut — meaning it degrades quickly and is not easily absorbed. Researchers are actively working on encapsulation technologies to improve delivery. Using concentrated essential oil internally in the belief it delivers therapeutic doses of citral is not supported by the evidence. Enjoy lemongrass as food. Drink the tea. Use the whole plant. Do not attempt to self-treat cancer with essential oil.
“Lemongrass is good for digestion.”
This is one of lemongrass’s best-supported traditional applications. The documented mechanisms: antispasmodic properties that reduce intestinal cramping; carminative effects that reduce gas accumulation; acceleration of gastric emptying; reduction of intestinal spasm through smooth muscle relaxation; and antimicrobial activity against Candida and pathogenic bacteria in the gut. The antispasmodic and carminative effects are consistent with the flavonoid and terpene profile — specifically isoorientin, which inhibits gut muscle contraction. This is not folk belief. It is mechanistically supported and consistent with multiple independent traditional uses across Asia, Africa, and South America.
“Lemongrass helps with fever.”
The use of lemongrass for fever is one of the most universal and consistent traditional applications across all cultures that have used it. In West Africa it is literally called “fever grass.” In Ayurveda it is classified as diaphoretic — promoting perspiration, which is one of the body’s primary mechanisms for reducing fever. The direct antipyretic (fever-reducing) effect in animal studies required intraperitoneal injection rather than oral administration, suggesting the mechanism is not straightforward. However, the anti-inflammatory properties, the diaphoretic effect, and the antimicrobial activity against the pathogens that often cause fever are all documented. The traditional use is well-founded even if the single mechanism of “this compound directly reduces temperature” is not cleanly proven.
Serai — How To Get the Best From It
The whole plant, used traditionally, remains the most pharmacologically complete preparation available.
The most ancient and most consistent delivery method. Bruise the bulb end, add to soups, curries, and rice dishes. The heat extracts the citral and other essential oil compounds into the dish. The Malay kitchen’s daily use of serai is not incidental — it is maintenance. Daily consumption at culinary levels provides continuous low-dose phytochemical input.
Bruise 2–3 stalks of fresh serai (smash the base with the back of a knife). Add to water just below boiling. Steep 10–15 minutes. Strain and drink. Best taken without sugar or with honey. For digestive complaints, drink after meals. For fever, drink warm. One to three cups daily. This is the preparation with the longest documented traditional use.
Simmer the stalks (fresh or dried) in water for 20–30 minutes rather than steeping. A decoction extracts a fuller range of water-soluble compounds than a simple infusion. The resulting liquid is stronger and more bitter. Traditional use for fever, muscle pain, and digestive disturbance used decoctions, not light teas. For serious applications, this preparation is more appropriate.
Add a strong decoction of serai to bathing water for muscle and joint pain, or for the postpartum cleansing tradition used in Malay culture. Apply a warm compress of bruised serai stalks to areas of localised pain or skin infection. The antimicrobial properties are directly relevant to topical application. Diluted essential oil — 2–3% in carrier oil — for topical pain relief and skin conditions.
The anxiolytic effects that were not confirmed for oral tea showed more promise in inhalation studies. Diffuse lemongrass essential oil for stress and mental clarity. The citral molecule, inhaled, reaches the olfactory-limbic system through a different pathway than oral consumption. The traditional practice of scenting living spaces with serai had pharmacological rationale the tradition did not need to explain.
Drop 2–3 drops of lemongrass essential oil on cotton wool and place it near the entrance of an empty hive box. The citral mimics the honeybee Nasonov pheromone and attracts wild swarms. This works because the bee cannot distinguish the serai citral from its own homing signal. The kitchen herb is the beekeeper’s most effective swarm lure.
Honest Assessment
Well-documented: Antimicrobial activity against a broad spectrum of bacteria, fungi, and yeasts. Anti-inflammatory activity through NF-κB inhibition and flavonoid modulation. Antioxidant properties. Digestive applications including antispasmodic, carminative, and gastric-emptying effects. Cholesterol-lowering effects. Diuretic properties. The extraordinary MRSA sensitisation finding. The compelling but preliminary anticancer research.
Requires more research: Human clinical trials specifically targeting cancer, blood pressure, and anxiety outcomes. Bioavailability studies to understand how citral behaves in the human digestive system at food concentrations vs. supplemental concentrations. The optimal preparation method for specific conditions.
The traditional record: Multiple independent civilisations, across thousands of years, converging on the same core applications. Fever. Digestion. Pain. Antimicrobial. This convergence is the most powerful signal available that something real and consistent is happening when this plant is used correctly.
The statements in this article have not been evaluated by the Ministry of Health (KKM) and are not intended to diagnose, treat, cure, or prevent any disease.
Lemongrass is safe at culinary doses — the amounts used in cooking and tea — for the vast majority of healthy adults. Concentrated essential oil is a different matter: undiluted lemongrass essential oil can cause skin irritation and sensitisation, and in large oral doses may be toxic. Never ingest concentrated essential oil without significant dilution and expert guidance. Some individuals have experienced contact dermatitis from topical lemongrass application; perform a skin patch test before extended topical use. Lemongrass has uterine-stimulating properties at high doses — pregnant women should limit use to culinary amounts and avoid therapeutic doses or essential oil. Those on blood-thinning medications should use caution as lemongrass may have antiplatelet properties. If you are on pharmaceutical medications, consult your healthcare provider before beginning any therapeutic use of lemongrass beyond normal cooking amounts.
References & Sources (click to expand)
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