Lemongrass

Lemongrass (Cymbopogon citratus) is a tall, tropical grass with a bright, citrusy scent that lands somewhere between fresh lemon and green tea. Snap or bruise a stalk and you release a wave of lemony aroma — that fragrance is mostly a compound called citral, and it is the heart of everything lemongrass does, from perfuming a bowl of Thai soup to filling a mug of calming bedtime tea. It is one of the great flavor herbs of Southeast Asia, and it is also a plant with a long folk-medicine history and a genuinely interesting (if still modest) scientific record.

This page keeps two things separate that often get blurred together. First, lemongrass the food and tea: delicious, gentle, and safe to enjoy freely. Second, lemongrass the concentrated essential oil: a potent extract with real laboratory activity that should be treated with respect — used on the skin only when diluted, and never swallowed. We will walk through what lemongrass is, how cooks and healers use its different parts, what compounds it contains, what the human and lab evidence honestly shows, and how to use it safely. Where the science is strong we will say so; where it is thin, we will say that too.

Table of Contents

  1. What Lemongrass Is
  2. A Kitchen Star of Southeast Asia
  3. Culinary vs. Medicinal: Different Parts
  4. The Active Compounds
  5. Traditional & Studied Uses
  6. What the Evidence Actually Shows
  7. Blood Pressure & Cholesterol: Early Signals
  8. Forms & How to Use It
  9. Safety: What to Know
  10. The Honest Bottom Line
  11. Research Papers
  12. Connections
  13. Featured Videos

What Lemongrass Is

Lemongrass is a perennial grass in the genus Cymbopogon, which contains dozens of aromatic grass species grown across the warm parts of Asia, Africa, and the Americas. The one that shows up on your dinner plate is almost always Cymbopogon citratus, often called West Indian lemongrass. It grows in dense, fountain-like clumps of slender blue-green blades that can reach chest height, thriving in hot, humid climates and full sun.

The part cooks prize is the lower stalk — the pale, tightly layered base just above the roots, which looks a bit like a firm, fibrous scallion. It is here that the citral is most concentrated and the texture is tender enough to eat. The long upper blades are tougher and more fibrous, so they are usually steeped for tea or oil rather than chewed. Fresh lemongrass smells unmistakably of lemon without any of the sourness — a clean, grassy, slightly floral citrus that has made it beloved far beyond its native range.

A Kitchen Star of Southeast Asia

If you have ever eaten a fragrant bowl of Thai tom yum soup, a Vietnamese lemongrass-marinated grilled pork, an Indonesian rendang, or a Sri Lankan curry, you have tasted lemongrass. It is a foundational aromatic across Thai, Vietnamese, Cambodian, Malaysian, Indonesian, and Sri Lankan cooking, where it plays a role similar to what a bay leaf or lemon zest might play elsewhere — a background brightness that lifts rich, spicy, coconut-heavy dishes.

Cooks use it a few different ways:

Its flavor partners beautifully with ginger, garlic, chili, galangal, lime leaf, fish sauce, and coconut milk — the classic Southeast Asian pantry. A little goes a long way, and the aroma blooms as it heats.

Culinary vs. Medicinal: Different Parts

One of the most useful things to understand about lemongrass is that the kitchen and the medicine cabinet reach for different parts of the same plant — and at very different strengths.

The stalk: for cooking

The pale lower stalk is the culinary workhorse. Eaten as food, it delivers flavor and only trace amounts of the aromatic oils — a completely gentle exposure.

The leaves and oil: for tea and traditional medicine

The long leaves, fresh or dried, are what people brew into lemongrass tea — the mild, pleasant beverage that carries most of the plant's folk-remedy reputation. Steeping releases small, food-level amounts of citral and flavonoids into the water.

Steam-distilling the leaves produces lemongrass essential oil, a highly concentrated extract that can be 70–85% citral. This is a different animal entirely: it is the form used in most laboratory studies, in aromatherapy, and in natural insect repellents. Because it is so concentrated, it must be handled with care — diluted before it ever touches skin, and never swallowed. Keeping the tea and the oil mentally separate is the single most important safety idea on this page.

The Active Compounds

Lemongrass owes both its aroma and its biological activity to a small cast of plant chemicals:

In short: the volatile terpenes (led by citral) drive the aroma and the antimicrobial/insect-repellent effects, while the flavonoids and polyphenols contribute the antioxidant capacity you get from a cup of tea.

Traditional & Studied Uses

Lemongrass has a deep folk-medicine history across the tropics, and modern science has picked up several of these threads in the lab. Here is where tradition and study overlap.

A calming, sleep-friendly tea

In Brazil and much of Latin America, lemongrass (capim-santo or abafado) is a classic bedtime tea taken to ease nerves and encourage sleep. This calming reputation is genuine folk knowledge; the science, as we will see below, is encouraging in animals but not yet proven in people.

Digestive and carminative use

Warm lemongrass tea is a traditional after-meal drink for bloating, gas, stomach cramps, and general indigestion — a "carminative," meaning it is believed to soothe the gut and help move trapped gas. This is one of the most widespread and time-honored uses.

Traditional fever and cold use

In the Caribbean, lemongrass is literally nicknamed "fever grass" and brewed as a hot tea to sweat out fevers, colds, and flu-like illness. Across Asia and Africa it appears in similar cold-and-fever remedies.

Insect repellent — the citronella connection

The famous mosquito-repelling citronella comes mainly from lemongrass's close cousins Cymbopogon nardus and Cymbopogon winterianus, not from culinary C. citratus. But the family resemblance is real: lemongrass oil itself contains repellent terpenes, and formulated lemongrass-oil products have shown meaningful (if short-lived) protection against mosquito bites in testing.

What the Evidence Actually Shows

Here is the honest picture, sorted by how strong the evidence really is.

Strong in the lab: antimicrobial, antifungal, antioxidant

This is where lemongrass genuinely shines. In test tubes and petri dishes, lemongrass essential oil — driven by citral — is a potent antimicrobial. It inhibits a wide range of bacteria (including Staphylococcus aureus and food-spoilage organisms), disrupts bacterial biofilms, and shows clear antifungal activity against Candida yeasts. The oil and the leaf extracts also test as strong antioxidants, mopping up free radicals in standard assays. These lab findings are consistent and repeatable. The important caveat: activity in a dish is not the same as a proven treatment in a human body, where dose, absorption, and safety all change the equation.

Limited but encouraging in people

A handful of small human studies have tested lemongrass directly, mostly applied topically:

The overall verdict: lemongrass has excellent laboratory credentials and a few promising small human trials, but it has not been put through the large, rigorous clinical trials that would let anyone call it a proven medicine. It is best thought of as a wonderful food and a pleasant, low-risk tea — not a treatment.

Blood Pressure & Cholesterol: Early Signals

Two popular claims deserve a careful, honest look.

Cholesterol. One frequently cited early study gave volunteers lemongrass oil capsules and tracked their serum cholesterol. The results were modest and inconsistent: some participants saw a meaningful drop, while others did not respond at all. It was a small, preliminary study — interesting enough to keep researchers curious, but nowhere near strong enough to recommend lemongrass as a cholesterol treatment.

Blood pressure. Lemongrass tea is widely claimed to lower blood pressure, and there are small reports and animal data hinting at mild effects. But the human evidence is thin and short-term, and no solid trial has confirmed a lasting benefit. If you take blood-pressure medication, enjoy the tea as a beverage — but do not treat it as a substitute for your prescription, and mention regular medicinal use to your doctor.

Forms & How to Use It

Lemongrass comes in several forms, and matching the form to the purpose keeps things both effective and safe.

Safety: What to Know

The good news first: as a culinary herb and as tea, lemongrass is very safe. It has a long record of everyday food use across many cultures, and the one human trial that specifically looked for toxicity from lemongrass tea found none. For most people, cooking with it and drinking a few cups of tea is worry-free.

The cautions all cluster around the concentrated oil and a few special situations:

The Honest Bottom Line

Lemongrass is one of those rare herbs that is a genuine delight in the kitchen and a sensible, low-risk pick for a soothing cup of tea. The laboratory data behind it are real and consistent — strong antimicrobial, antifungal, and antioxidant activity from its citral-rich oil — and a few small human studies (oral thrush, dandruff) are quietly encouraging. At the same time, the big claims about anxiety, sleep, blood pressure, and cholesterol rest on animal work and small, mixed, or null human trials, so honesty means calling them promising-but-unproven rather than established.

So enjoy lemongrass for what it clearly is: a bright, lemony flavor that lifts your cooking, and a pleasant, calming tea to unwind with. Cook with the stalks freely, sip the tea happily, treat the concentrated essential oil with respect (diluted on skin, never swallowed), and don't ask a cup of tea to do a doctor's job. On those terms, lemongrass earns its long-loved place in both the kitchen and the teapot.

Research Papers

  1. Shah G, Shri R, Panchal V, Sharma N, Singh B, Mann AS. Scientific basis for the therapeutic use of Cymbopogon citratus, stapf (Lemon grass). Journal of Advanced Pharmaceutical Technology & Research. 2011;2(1):3–8. doi:10.4103/2231-4040.79796 — a comprehensive review of lemongrass phytochemistry and its traditional and pharmacological uses.
  2. Ekpenyong CE, Akpan E, Nyoh A. Ethnopharmacology, phytochemistry, and biological activities of Cymbopogon citratus (DC.) Stapf extracts. Chinese Journal of Natural Medicines. 2015;13(5):321–337. doi:10.1016/S1875-5364(15)30023-6 — maps the active compounds (citral, flavonoids, polyphenols) to their studied biological effects.
  3. Costa CA, Kohn DO, de Lima VM, Gargano AC, Flório JC, Costa M. The GABAergic system contributes to the anxiolytic-like effect of essential oil from Cymbopogon citratus (lemongrass). Journal of Ethnopharmacology. 2011;137(1):828–836. doi:10.1016/j.jep.2011.07.003 — found calming effects in mice and traced part of the mechanism to the brain's GABA system.
  4. Leite JR, Seabra ML, Maluf E, et al. Pharmacology of lemongrass (Cymbopogon citratus Stapf). III. Assessment of eventual toxic, hypnotic and anxiolytic effects on humans. Journal of Ethnopharmacology. 1986;17(1):75–83. doi:10.1016/0378-8741(86)90074-7 — an honest human trial: lemongrass tea showed no measurable anxiolytic or hypnotic effect, and no toxicity.
  5. Cheel J, Theoduloz C, Rodríguez J, Schmeda-Hirschmann G. Free radical scavengers and antioxidants from lemongrass (Cymbopogon citratus (DC.) Stapf.). Journal of Agricultural and Food Chemistry. 2005;53(7):2511–2517. doi:10.1021/jf0479766 — identified the antioxidant compounds behind lemongrass's free-radical-scavenging activity.
  6. Naik MI, Fomda BA, Jaykumar E, Bhat JA. Antibacterial activity of lemongrass (Cymbopogon citratus) oil against some selected pathogenic bacterias. Asian Pacific Journal of Tropical Medicine. 2010;3(7):535–538. doi:10.1016/S1995-7645(10)60129-0 — demonstrated broad laboratory antibacterial activity of the essential oil.
  7. Boukhatem MN, Ferhat MA, Kameli A, Saidi F, Kebir HT. Lemon grass (Cymbopogon citratus) essential oil as a potent anti-inflammatory and antifungal drugs. Libyan Journal of Medicine. 2014;9:25431. doi:10.3402/ljm.v9.25431 — showed anti-inflammatory and anti-Candida antifungal activity of the oil in laboratory models.
  8. Wright SC, Maree JE, Sibanyoni M. Treatment of oral thrush in HIV/AIDS patients with lemon juice and lemon grass (Cymbopogon citratus) and gentian violet. Phytomedicine. 2009;16(2–3):118–124. doi:10.1016/j.phymed.2008.07.015 — a small human trial suggesting benefit against oral Candida (thrush).
  9. Chaisripipat W, Lourith N, Kanlayavattanakul M. Anti-dandruff hair tonic containing lemongrass (Cymbopogon flexuosus) oil. Complementary Medicine Research. 2015;22(4):226–229. doi:10.1159/000432407 — a small controlled study in which a lemongrass-oil tonic reduced dandruff.
  10. Elson CE, Underbakke GL, Hanson P, Shrago E, Wainberg RH, Qureshi AA. Impact of lemongrass oil, an essential oil, on serum cholesterol. Lipids. 1989;24(8):677–679. doi:10.1007/BF02535203 — an early, small human study with modest and inconsistent cholesterol effects.
  11. Oyedele AO, Gbolade AA, Sosan MB, Adewoyin FB, Soyelu OL, Orafidiya OO. Formulation of an effective mosquito-repellent topical product from lemongrass oil. Phytomedicine. 2002;9(3):259–262. doi:10.1078/0944-7113-00120 — a formulated lemongrass-oil product gave meaningful, if short-lived, protection from mosquito bites.
  12. de Groot A, Schmidt E. Essential Oils, Part V: Peppermint Oil, Lavender Oil, and Lemongrass Oil. Dermatitis. 2016;27(6):325–332. doi:10.1097/DER.0000000000000218 — reviews the skin-irritation and contact-allergy risks of lemongrass essential oil.

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Connections

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