Lemon grass: one tea trial, and its kidney signal

The only human trial we found gave lemongrass as tea. In 105 adults aged 18 to 35, randomly assigned to an infusion made from 2, 4 or 8 g of leaf powder once a day for 30 days, hemoglobin, packed cell volume and red cell count rose in all groups. A second paper on the same people reported creatinine clearance and eGFR, two measures of kidney function, falling significantly by day 30 in every dose group, and the authors called the effect dose and time dependent. Neither paper had a placebo group. People were compared with their own starting values, the abstracts give no size for either change, and whether the kidney drop matters clinically was not assessed. For the uses people search for, blood pressure, blood sugar and weight loss, we found no human trial of lemongrass tea.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• Raw lemon grass has 99 calories per 3.5 oz (100 g), with 8.17 mg iron, 5.224 mg manganese and 723 mg potassium. — USDA SR Legacy record for Lemon grass (citronella), raw Evidence E source
  Energy 99 calories; carbohydrate 25.31 g; protein 1.82 g; iron 8.17 mg; manganese 5.224 mg; potassium 723 mg; zinc 2.23 mg; folate 75 ug per 3.5 oz (100 g)

What a real portion looks like

• A tablespoon of lemon grass weighs 4.8 g and supplies about 0.4 mg iron and 5 calories. — USDA SR Legacy portion weights for Lemon grass (citronella), raw Evidence E source
  1 tbsp 4.8 g: about 0.39 mg iron, 4.8 calories; 1 cup 67 g: about 5.5 mg iron, 66 calories (computed from per 3.5 oz (100 g))

What cooking and storage change

• Lab work on lemongrass oil shows the extraction method changes how much citral ends up in it, with microwave-assisted and supercritical CO2 yielding more. — literature on lemongrass essential oil chemistry and extraction, 1996 to 2022 Evidence D source
  Microwave assisted hydrodistillation and supercritical CO2 extraction yield more citral than other methods

What it does to your health

• In 105 adults aged 18 to 35, a daily infusion of 2, 4 or 8 g lemongrass leaves for 30 days raised hemoglobin, packed cell volume and red cell count. — One hundred five subjects (55 men and 50 women), aged 18 to 35 years (n = 105) Evidence B source
  PCV, Hb and RBC significantly increased (P<.05) in all subjects, mostly by day 30; white cells decreased
• A review placed citral, a lemongrass compound, among essential oil compounds with anti-diabetic effects in diabetes-related animal models. — animal and cell studies of dietary essential oil compounds, 2010 to 2022 Evidence D source
  Citral among compounds with anti-diabetic effects via glucose signaling pathways in diabetes-related animal models

Safety, limits and interactions

• In the same 105 adults, lemongrass tea from 2 to 8 g of leaf powder daily lowered eGFR and creatinine clearance by day 30 in every dose group. — One hundred five subjects (55 men and 50 women) aged 18 to 35 years (n = 105) Evidence B source
  CCr and eGFR decreased significantly at day 30 in all groups; serum creatinine rose; at day 10 diuretic indices increased

What people believe that the data does not support

• In a survey of 274 Saudi students, 38.3% believed lemongrass has antiviral and immunity-boosting properties. — 274 healthcare and non-healthcare students at King Saud University (n = 274) Evidence C source
  38.3% agreed lemongrass is antiviral or immunity-boosting; ginger 75.2%, garlic 59.5%

The bottom line

As an ingredient it adds little. USDA lists 8.17 mg of iron, 723 mg of potassium and 99 calories per 3.5 oz (100 g) of raw lemon grass, but a tablespoon weighs 4.8 g and gives about 0.4 mg of iron, and in many dishes the stalk is taken out before eating. How much of those minerals passes into tea is unknown. The diabetes claim rests on animals. A review of essential oil compounds found citral acting on glucose pathways in animal and cell studies of diabetes, and the dose of citral in a cup of tea is unknown. Lab work on the oil shows that the extraction method changes how much citral ends up in it, which tells you nothing about fresh grass in cooking. In a survey of 274 Saudi students, 38.3% believed lemongrass protects against viruses. That measures belief, and we found no trial that tested it. If you have kidney disease, the falling eGFR seen in healthy young adults is a reason to ask whoever treats you before drinking lemongrass tea every day. We found no studies on pregnancy, children or medicines, so its safety in those groups has not been tested.

Sources

1. lmgr-r1-01 · reference dataset
   SR Legacy FDC 168573 Lemon grass (citronella), raw: Energy 99 kcal | Carbohydrate, by difference 25.31 g | Protein 1.82 g | Iron 8.17 mg | Manganese 5.224 mg | Potassium 723 mg | Zinc 2.23 mg | Folate, total 75 ug per 100 g
   USDA SR Legacy 2018 (FoodData Central), FDC 168573 Lemon grass (citronella), raw · checked 2026-10-02
2. lmgr-r1-02 · reference dataset
   SR Legacy FDC 168573 Lemon grass (citronella), raw: food_portion 1 tbsp 4.8 g | 1 cup 67 g || Iron 8.17 mg, Energy 99 kcal per 100 g
   USDA SR Legacy 2018 (FoodData Central), FDC 168573 Lemon grass (citronella), raw · checked 2026-10-02
3. lmgr-r1-05 · systematic review
   This article points out that different extraction techniques yield different percentages of citral and other secondary metabolites from lemon grass, for example, microwave assisted hydrodistillation and supercritical carbon dioxide extraction process yields more citral.
   J Am Nutr Assoc, 2024 · checked 2026-10-02
4. lmgr-r1-03 · randomized controlled trial
   One hundred five subjects (55 men and 50 women), aged 18 to 35 years, were randomly assigned to groups set to orally receive infusion prepared from 2, 4, or 8 g of C. citratus leaves once daily for 30 days. ... Infusions prepared from C. citratus leaf powder, which tested positive for tannins, saponins, alkaloids, flavonoids, macro- and micronutrients, significantly increased PCV, Hb, and RBC (P<.05) in all subjects, particularly in the subchronic phase of the study.
   J Med Food, 2015 · checked 2026-10-02
5. lmgr-r1-06 · systematic review
   According to the results, the essential oil compounds, including cinnamaldehyde, carvacrol, zingerone, sclareol, zerumbone, myrtenol, thujone, geraniol, citral, eugenol, thymoquinone, thymol, citronellol, α-terpineol, and linalool have been demonstrated to contain strong anti-diabetic effects via modulating various signal transduction pathways linked to glucose metabolism. Additionally, in diabetes-related animal models, they can also considerably reduce the expression of TNF-α, IL-1β, IL-4, IL-6, iNOS, and COX-2.
   Crit Rev Food Sci Nutr, 2024 · checked 2026-10-02
6. lmgr-r1-04 · randomized controlled trial
   One hundred five subjects (55 men and 50 women) aged 18 to 35 years were randomly assigned to groups set to orally receive infusions prepared from 2, 4, or 8 g of C citratus leaf powder once daily, for 30 days. ... CCr and eGFR decreased significantly at day 30 in both male and female subjects in all the groups and in females treated with infusion prepared from 8 g of C citratus leaf powder for 10 days. ... We observed dose- and time-dependent adverse effects of C citratus on CCr and eGFR.
   J Ren Nutr, 2015 · checked 2026-10-02
7. lmgr-r1-07 · cross-sectional survey
   A total of 274 participants responded to the study. ... A majority (75.2%) of the respondents agreed that ginger extract possesses antiviral and immunity-boosting properties, followed by garlic extract (59.5%), cinnamon (39.4%), and lemongrass (38.3%).
   Inquiry, 2022 · checked 2026-10-02