Orthosiphon (Java tea, cat's whiskers)

Q: Does Java tea help kidney stones?

In a 48-person Thai trial, two cups a day for up to 18 months shrank stones at a rate similar to sodium potassium citrate (28.6% vs 33.8% a year). There was no placebo group.

Q: Does it help with water retention or bloating?

No trial cited here tested water retention. The EU listing covers urinary flushing for minor complaints, based on traditional use rather than trials.

Q: Is Orthosiphon safe?

The EU monograph lists no known side effects or interactions, but advises against it with severe heart or kidney disease, in pregnancy and under 18.

Q: Does Orthosiphon interact with medicines?

The EU herbal monograph reports no known interactions, and we found no human interaction studies. Because it is used to increase urine flow with plenty of fluids, it is not suited to people told to limit fluids.

Q: Is cat's whiskers the same as Java tea?

Yes. Cat's whiskers, Java tea, Orthosiphon stamineus and O. aristatus are names for the same plant.

Q: Is Orthosiphon a diuretic?

In rats, yes. In a double-blind placebo-controlled crossover trial in healthy people, it did not increase 12- or 24-hour urine output or sodium excretion.

Q: What did the cancer fatigue trial find?

A 9-week phase II trial in 110 chemotherapy patients found less fatigue with 3 g/day of a proprietary extract than placebo. It was sponsored by Natureceuticals, the extract's developer, and several authors work for the private companies EMAN Biodiscoveries and EMAN Research. It has not been repeated.

Also called Java tea, cat's whiskers, Orthosiphon stamineus, Orthosiphon aristatus, Orthosiphon grandiflorus, Orthosiphonis folium.

Best grade D across 3 graded outcomes Botanical Last checked Oct 21, 2026

The short answer

From 7 sources

Orthosiphon, also called Java tea or cat's whiskers, is sold as a urinary "flushing" and draining herb. Its EU status rests on traditional use, and the one placebo-controlled diuretic trial found no increase in urine output (grade D). A tea did about as well as a citrate drug on kidney stone size, and a company-linked extract eased cancer fatigue in one trial (grade D).

Every graded outcome on this page

3 rows · line = participants

Grade DCancer-related fatigue during chemotherapyFatiguen 110
Grade DKidney stone size vs sodium potassium citrateKidney stonesn 48
Grade D24-hour urine output and sodium excretion in healthy volunteersUrine outputn 40

Key facts

Botanical name: Orthosiphon aristatus var. aristatus; Orthosiphon stamineus and O. grandiflorus are synonyms^6,4
EU status: Traditional herbal medicine to increase urine for flushing in minor urinary complaints, based on long-standing use only⁴
Diuretic trial: No change in 24-hour urine output or sodium excretion vs placebo in a double-blind crossover trial¹
Kidney stones: Stone shrinkage with the tea was similar to sodium potassium citrate over up to 18 months (no placebo)²
Cancer fatigue: One industry-sponsored phase II trial of a proprietary extract (110 patients) reported less fatigue than placebo^3,7

What it is

Orthosiphon (Java tea, cat's whiskers) is a Southeast Asian leaf used in teas and urinary "flushing" products.

How it works

Proposed

In rats, Orthosiphon water extract increased urine volume and potassium excretion in a dose-dependent way, though less than furosemide or hydrochlorothiazide. The 1992 human crossover trial did not reproduce a diuretic effect.^5,1

Forms, side by side

3 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.

Orthosiphon (Java tea, cat's whiskers) forms compared

3 forms

Orthosiphon (Java tea, cat's whiskers) forms compared: 3 forms by 3 attributes. Empty cells are labelled No data yet, or Not graded in the evidence row.
3 forms	Leaf tea (infusion)	Standardized leaf extract (Nuvastatic, C5OSEW5050ESA)	Other dry or liquid extracts
Absorption in people	No human absorption data.⁴	No human absorption data.³	No human absorption data.⁴
GI tolerance	The EU monograph lists no known undesirable effects; tolerability is not reported in the tea trial abstract.^4,2	Vomiting 0.9%, fever 5.4% and headache 2.7% were reported over 9 weeks at 3 g/day in chemotherapy patients.³	Covered by the EU traditional-use monograph at the listed extract amounts; no trials cited here.⁴
Studied for	Kidney stones (vs citrate); the EU traditional-use amount is 6–12 g of leaf a day as tea	Cancer-related fatigue	Traditional urinary flushing use only

Leaf tea (infusion)
Absorption in people
No human absorption data.⁴
GI tolerance
The EU monograph lists no known undesirable effects; tolerability is not reported in the tea trial abstract.^4,2
Studied for
Kidney stones (vs citrate); the EU traditional-use amount is 6–12 g of leaf a day as tea
Standardized leaf extract (Nuvastatic, C5OSEW5050ESA)
Absorption in people
No human absorption data.³
GI tolerance
Vomiting 0.9%, fever 5.4% and headache 2.7% were reported over 9 weeks at 3 g/day in chemotherapy patients.³
Studied for
Cancer-related fatigue
Other dry or liquid extracts
Absorption in people
No human absorption data.⁴
GI tolerance
Covered by the EU traditional-use monograph at the listed extract amounts; no trials cited here.⁴
Studied for
Traditional urinary flushing use only

What the human research says

Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.

Trial map

3 graded outcomes, largest study first

3 graded outcomes: 1 improved, 1 mixed, 1 no effect. The largest, a 2024 randomized trial of 110 people on Cancer-related fatigue during chemotherapy, found an improvement.

By sizeTable

1Cancer-related fatigue during chemotherapy

Improved · Grade D · RCT, 110 people, 2024

Adults with stage II–IV solid tumours receiving chemotherapy (multicentre trial)

Dose, result and source

Every graded outcome on this page, largest study first
Outcome	Found	People	Study	Who was studied
Cancer-related fatigue during chemotherapy	Improved	110	Grade D · RCT, 2024	Adults with stage II–IV solid tumours receiving chemotherapy (multicentre trial)
Kidney stone size vs sodium potassium citrate	Mixed	48	Grade D · RCT, 2001	Rural adults with kidney stones on ultrasound (Thailand)
24-hour urine output and sodium excretion in healthy volunteers	No effect	40	Grade D · Crossover RCT, 1992	Healthy volunteers (Vietnam)

Every graded row

3 rows

Grade DCancer-related fatigue during chemotherapyFatigueImprovedRCT
n 110 · 2024

Improved Brief Fatigue Inventory and visual-analogue fatigue scores fell more than with placebo (p<0.001), with better quality of life and lower urinary F2-isoprostanes. Reported adverse events were vomiting (0.9%), fever (5.4%) and headache (2.7%).

Design: RCT, n = 110, 2024
Population: Adults with stage II–IV solid tumours receiving chemotherapy (multicentre trial)
Form: Nuvastatic (C5OSEW5050ESA), a standardized rosmarinic acid-rich Orthosiphon stamineus leaf extract
Dose: 1,000 mg three times daily
Duration: 9 weeks
Source: Reference 3 · PubMed 38710920 (opens PubMed)

Grade DKidney stone size vs sodium potassium citrateKidney stones28.6% vs 33.8%/yearRCT
n 48 · 2001

Mixed Stones shrank about 28.6% a year with the tea vs 33.8% with sodium potassium citrate, a difference that was not significant. There was no placebo group.

Design: RCT, n = 48, 2001
Population: Rural adults with kidney stones on ultrasound (Thailand)
Form: Orthosiphon grandiflorus tea (a synonym of the same species)
Dose: 2 cups of tea a day, 2.5 g dried herb per tea bag
Duration: Up to 18 months
Source: Reference 2 · PubMed 11944733 (opens PubMed)

Grade D24-hour urine output and sodium excretion in healthy volunteersUrine outputNo change vs placeboCrossover RCT
n 40 · 1992

No effect No effect on 12- or 24-hour urine output or on sodium excretion compared with placebo under standardized conditions.

Design: Crossover RCT, n = 40, 1992
Population: Healthy volunteers (Vietnam)
Form: Traditional Orthosiphon stamineus herbal remedy
Dose: Traditional preparation (amount given in the full text, not the abstract)
Duration: Placebo-controlled crossover periods
Source: Reference 1 · PubMed 1434681 (opens PubMed)

What the numbers add up to

Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.

Tradition vs the trial

Orthosiphon's EU listing is for increasing urine, yet the only placebo-controlled human test of that effect found none.^4,1

No placebo in the stone trial

The kidney stone result shows the tea matched a citrate drug, not that it beat doing nothing.²

Studied doses

Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.

Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.

Doses studied in human trials

Doses studied in human trials ranged from a traditional preparation in short crossover periods and two cups of tea a day (2.5 g of leaf each) for up to 18 months, to 3 g/day of a standardized extract for 9 weeks.^1,2,3

Interactions and safety

Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.

Interactions

0 agents

None found in our sources.

Check with what you take

Kept on this device only

Add what you take. We list every interaction our evidence profiles cite between Orthosiphon and your picks, and between your picks.

Add a supplement or medicine

Most cited:

Add a supplement or medicine you take to check it against Orthosiphon.

Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.

Who should be careful

7 groups

Severe heart or kidney disease: The EU monograph rules it out where reduced fluid intake is advised, such as severe cardiac or renal disease, and says adequate fluid intake is needed during use. Rats given the extract showed slight rises in blood urea nitrogen and creatinine, though within normal ranges.^4,5
Under 18: Not recommended in children and adolescents because of a lack of adequate data.⁴
Pregnancy and breastfeeding: Safety has not been established, and the EU monograph does not recommend use.⁴
Urinary symptoms that need a diagnosis: The EU monograph says fever, painful urination, spasms or blood in the urine need a doctor, and symptoms lasting over 2 weeks should be checked.⁴
People with kidney stones: The stone trial compared the tea with a citrate drug under regular ultrasound follow-up, not with no treatment; it does not support using the tea in place of medical care for stones.²
People having chemotherapy: The fatigue data come from one industry-sponsored trial of one proprietary extract; any supplement during chemotherapy should be agreed with the oncology team.^3,7
People on medicines: The EU herbal monograph lists no reported interactions with other medicines, and we found no interaction studies in people. It also rules out use where fluid intake must be limited, such as severe heart or kidney disease.⁴

How to read the label

What to check on the Supplement Facts panel.

How to read the label

3 checks

Same plant, many names

Labels may say Java tea, cat's whiskers, Orthosiphon stamineus, O. aristatus or O. grandiflorus; botanical databases list these as one plant.⁶

"Draining" claims

The only placebo-controlled human diuretic test found no extra urine output, so draining or water-weight claims rest on tradition and rat data.^1,5,4

Proprietary extracts differ

The fatigue trial used one standardized, rosmarinic acid-rich extract at 3 g/day; results may not apply to plain leaf tea.³

Frequently asked questions

Short answers to common questions; the numbers link to the sources below.

Common questions

7 answers

Does Java tea help kidney stones?

In a 48-person Thai trial, two cups a day for up to 18 months shrank stones at a rate similar to sodium potassium citrate (28.6% vs 33.8% a year). There was no placebo group.²

Does it help with water retention or bloating?

No trial cited here tested water retention. The EU listing covers urinary flushing for minor complaints, based on traditional use rather than trials.⁴

Is Orthosiphon safe?

The EU monograph lists no known side effects or interactions, but advises against it with severe heart or kidney disease, in pregnancy and under 18.⁴

Does Orthosiphon interact with medicines?

The EU herbal monograph reports no known interactions, and we found no human interaction studies. Because it is used to increase urine flow with plenty of fluids, it is not suited to people told to limit fluids.⁴

Is cat's whiskers the same as Java tea?

Yes. Cat's whiskers, Java tea, Orthosiphon stamineus and O. aristatus are names for the same plant.^6,4

Is Orthosiphon a diuretic?

In rats, yes. In a double-blind placebo-controlled crossover trial in healthy people, it did not increase 12- or 24-hour urine output or sodium excretion.^5,1

What did the cancer fatigue trial find?

A 9-week phase II trial in 110 chemotherapy patients found less fatigue with 3 g/day of a proprietary extract than placebo. It was sponsored by Natureceuticals, the extract's developer, and several authors work for the private companies EMAN Biodiscoveries and EMAN Research. It has not been repeated.^3,7

Sources

7 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.

Sources cited on this page

7 sources

1Studies on the individual and combined diuretic effects of four Vietnamese traditional herbal remedies (Zea mays, Imperata cylindrica, Plantago major and Orthosiphon stamineus).Crossover RCT J Ethnopharmacol, 1992 · PMID 1434681
2A long-term study on the efficacy of a herbal plant, Orthosiphon grandiflorus, and sodium potassium citrate in renal calculi treatment.RCT Southeast Asian J Trop Med Public Health, 2001 · PMID 11944733
3A phase II randomized, double-blind, placebo-controlled study of Nuvastatic (C50SEW505OESA), a standardized rosmarinic acid-rich polymolecular botanical extract formulation to reduce cancer-related fatigue in patients with solid tumors.RCT Support Care Cancer, 2024 · PMID 38710920
4European Union herbal monograph on Orthosiphon aristatus (Blume) Miq. var. aristatus, folium - Revision 1 (EMA/HMPC/486551/2020)Guideline European Medicines Agency, 2021 · ema.europa.eu
5Diuretic properties of Orthosiphon stamineus Benth.Animal study J Ethnopharmacol, 2009 · PMID 19375494
6Orthosiphon aristatus var. aristatus (accepted name; synonyms include Orthosiphon stamineus and Orthosiphon grandiflorus)Database Plants of the World Online, Royal Botanic Gardens, Kew, 2026 · powo.science.kew.org
7Evaluation of Clinical Efficacy and Safety of Nuvastatic in Cancer Asthenia (NCT04546607)Database ClinicalTrials.gov, 2020 · clinicaltrials.gov

What changed

Every dated change to this page: what changed, who made it and why.

Change log

3 entries

Dated changes to this page
Date	Change	Who and why
Oct 21, 2026who should be careful, FAQ	Added the EU herbal monograph's interactions statement (none reported) as a medicines note and FAQ. A 2018–2026 PubMed search found no new human trial.	Writer: Kymata Health EditorialTrigger: A–Z page audit
Oct 14, 2026all	Initial editorial evidence review (first draft). Every PMID checked against NCBI E-utilities esummary (titles and years taken from the record; retraction, erratum and expression-of-concern links checked in the PubMed record) and the abstract read for each cited row. Studied doses are reported as research doses, not dosing advice. The page is named orthosiphon (the name used on supplement labels); the plant is also called cat’s whiskers. Combination blood-pressure products containing Orthosiphon were not used because their effects cannot be attributed to it. The 1992 trial's n comes from the full-text table; everything else is from abstracts, the EU monograph and Kew's Plants of the World Online.	Writer: Kymata Health EditorialTrigger: new page
Oct 14, 2026all	Adversarial review: cancer-fatigue trial now cites the ClinicalTrials.gov record (NCT04546607), whose lead sponsor is the industry developer Natureceuticals Sdn Bhd and which identifies the extract as Orthosiphon stamineus leaf (replacing the PubMed-keyword note); Ministry of Agriculture grant confirmed in Europe PMC. Added who-should-avoid entries for kidney stones and chemotherapy, and the EU monograph's fluid-intake condition. EU monograph wording (indication, 6–12 g tea, contraindications, under-18, pregnancy, 2-week rule, no known undesirable effects or interactions) re-checked against the PDF. The 1992 trial's n=40 comes from a paywalled full text and was not re-checked.	Writer: Kymata Health EditorialTrigger: review

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