Sera (Cymbopogon citratus): Lemongrass, Citral and a Calming Cup

Sera (Cymbopogon citratus) is the stalk you bruise and drop into a curry, and the tea you make when you want something warm that is not tea. Its lemon scent comes from a single dominant compound, and most of what lemongrass does — and most of what it should not be used for — follows from that one molecule.

Botanical and Cultural Background

Lemongrass is a tall tufted perennial grass of the Poaceae family, growing in dense clumps of sharp-edged blades from thickened stalk bases. It grows easily across Sri Lanka and is propagated by splitting a clump.

The tender lower stalk goes into curries; the leaves make tea. Its close relative citronella is the mosquito-repellent grass, and the two are often confused.

Phytochemistry

Lemongrass essential oil is dominated by citral — a mixture of geranial and neral — which gives it both the scent and most of its studied activity: antimicrobial, antifungal, anti-inflammatory and antioxidant in laboratory models.

What the Research Shows

Calming and sleep

The better-studied claim. Blanco and colleagues reported anxiolytic and sedative effects of the essential oil in mice, and lemongrass is a traditional calming tea across many cultures. Human trials are small.

Antimicrobial activity

Citral has well-demonstrated antimicrobial and antifungal activity in the laboratory — which supports lemongrass oil's use in cleaning and cosmetics more than any internal medicinal claim.

Digestion and fevers

Traditional. The warming, sweat-promoting tea is pleasant and hydrating during a cold; it does not shorten a viral illness.

Lemongrass is a pleasant, safe, mildly calming beverage with genuine antimicrobial chemistry. Claims that it detoxifies the body or treats arthritis go well beyond the evidence.

How Sera Is Used

Lemongrass tea: One or two stalks cut and lightly crushed, simmered ten minutes, strained, taken with ginger and honey.

In cooking: The bruised lower stalk added whole to curries and removed before serving.

Aromatherapy: A few drops of oil in a diffuser.

Safety and Precautions

Lemongrass as food and tea is safe for almost everyone and is among the gentlest plants on this site.

Lemongrass essential oil is a different matter. It must never be swallowed, and must be heavily diluted in a carrier oil before it touches skin — undiluted citral causes irritation and burning. Keep the oil away from children, and do not use it on babies' skin.

Avoid medicinal quantities of lemongrass tea in pregnancy. Lemongrass has traditional emmenagogue use and citral has shown effects on the uterus in animal studies. Culinary use of the stalk in food is not a concern; drinking strong lemongrass tea several times daily is best avoided, and the oil should not be used at all.

Lemongrass acts as a mild diuretic, so take care if you take diuretics or have kidney disease. Rare allergic reactions to the oil occur. If you take medication for blood pressure or blood sugar, mention high medicinal intake to your doctor. Don't confuse lemongrass with citronella — they're relatives, but citronella oil is for repelling insects, not for drinking.