Persicaria minor (kesum)

Also called Polygonum minus, kesum, Biokesum, LineMinus.

Best grade D across 1 graded outcome Botanical Last checked

The short answer

From 7 sources

Persicaria minor, called kesum in Malaysia, is a cooking herb sold as a standardized water extract. One small six-month placebo-controlled trial in 36 older adults with mild cognitive impairment, funded by the extract's maker, found better visual memory and mood scores. An earlier trial in middle-aged women was retracted. Evidence is preliminary.

Every graded outcome on this page

1 row · line = participants
  1. Grade DVisual memory and mood in older adults with mild cognitive impairmentMemory and moodn 36

Key facts

Only valid trial
36 adults aged 60-75 with mild cognitive impairment, 250 mg extract twice daily vs placebo for 6 months; 30 finished1
What changed
Visual Reproduction II memory scores, tension, anger and confusion improved vs placebo; MMSE, digit span and verbal learning did not1
Retracted study
A 2015 six-week trial of the extract in 35 middle-aged women was retracted by the journal in 201723
Industry funding
The 2020 trial was funded by Biotropics Malaysia, the maker of the Biokesum extract, which was also responsible for study design1
Agency safety reviews
No ODS, NCCIH, LactMed, LiverTox, Health Canada or EMA monograph covers this herb4

What it is

Persicaria minor (kesum) is a Malaysian culinary herb sold as a water extract for memory and mood support.

How it works

Proposed

Kesum leaves are rich in polyphenols and flavonoids. Lab and rat studies (not human data) suggest antioxidant and anti-inflammatory effects and better memory in rats with reduced brain blood flow. Whether these effects occur in people at supplement doses is unknown.56

Forms, side by side

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

Persicaria minor (kesum) forms compared

2 forms
Persicaria minor (kesum) forms compared: 2 forms by 3 attributes. Empty cells are labelled No data yet, or Not graded in the evidence row.
2 formsStandardized water extract capsules (e.g., Biokesum)Fresh leaves (cooking herb)
Absorption in peopleNo head-to-head human data1Not studied.5
GI toleranceNo adverse events were reported over 6 months in the 36-person trial.1Widely used as a flavoring herb in cooking; amounts in food are far lower than extract doses and have not been studied as a supplement.5
Studied forMemory and mood in older adults with mild cognitive impairmentNo human trials of the whole leaf
  1. Standardized water extract capsules (e.g., Biokesum)
    Absorption in people
    No head-to-head human data1
    GI tolerance
    No adverse events were reported over 6 months in the 36-person trial.1
    Studied for
    Memory and mood in older adults with mild cognitive impairment
  2. Fresh leaves (cooking herb)
    Absorption in people
    Not studied.5
    GI tolerance
    Widely used as a flavoring herb in cooking; amounts in food are far lower than extract doses and have not been studied as a supplement.5
    Studied for
    No human trials of the whole leaf
Every cell holds data from a cited page; citation numbers link to the page that holds them.Scroll the table for every column

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

1 graded outcome, largest study first

One graded outcome so far. Visual memory and mood in older adults with mild cognitive impairment: a 2020 randomized trial of 36 people found an improvement.

Bar: the ages a study enrolled (running to the edge when it states no upper or lower limit). Dot: only a mean age, counted as near your age within 5 years. Tick: the mean age inside a range.

1Visual memory and mood in older adults with mild cognitive impairment: improved, 60–75

1. Visual memory and mood in older adults with mild cognitive impairment: improved, 36 people1

1Visual memory and mood in older adults with mild cognitive impairment

Improved · Grade D · RCT, 36 people, 2020

Malaysian community-dwelling adults aged 60-75 with mild cognitive impairment

Dose, result and source
Every graded outcome on this page, largest study first
OutcomeFoundPeopleStudyWho was studied
Visual memory and mood in older adults with mild cognitive impairmentImproved36Grade D · RCT, 2020Malaysian community-dwelling adults aged 60-75 with mild cognitive impairment
Each circle is one graded outcome on this page, numbered from the largest study down, and placed by how many people it studied (log scale). By age shows the ages each study enrolled, where it states them. It shows who was studied and what was found, not advice about your dose.

Every graded row

1 row
Grade DVisual memory and mood in older adults with mild cognitive impairmentMemory and moodSmall gains on some testsRCT
n 36 · 2020

Improved Visual Reproduction II scores, tension, anger, confusion and total negative mood improved vs placebo, as did BDNF and triglycerides. Other memory tests (MMSE, digit span, verbal learning, digit symbol) did not differ. 30 of 36 finished; brain-scan findings in 15 people were labelled preliminary.

Design
RCT, n = 36, 2020
Population
Malaysian community-dwelling adults aged 60-75 with mild cognitive impairment
Form
Biokesum water extract of P. minor (250 mg capsules)
Dose
250 mg twice daily (500 mg/day)
Duration
6 months
Source
Reference 1 · PubMed 33076878 (opens PubMed)

Lab and animal research (preclinical)

2 notes

None of this has been shown in people.

Genotoxicity tests (lab)
The Biokesum extract was negative in three standard OECD guideline genotoxicity tests (a bacterial mutation test, a chromosomal aberration test and a micronucleus test). These lab tests do not show safety in people at supplement doses.7
Memory in rats
In rats with chronically reduced brain blood flow, Persicaria minor improved cognitive function.6

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.

One trial left standing

Of two placebo-controlled trials of kesum extract, one was retracted. The remaining trial had 30 completers and was funded and designed with the manufacturer.13

How we got this: Retraction notice and the 2020 trial's funding statement

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 250 mg of water extract twice a day (500 mg/day) for 6 months in the only non-retracted placebo-controlled trial. These are research doses, not recommendations.1

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 Persicaria minor and your picks, and between your picks.

Most cited:

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

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.

Not medical advice, and no dosing advice. An empty result means no row we cite names that pair, by name or through a drug class we can link the medicine to, not that a combination is safe. Where our sources name only a group of medicines we cannot match, the cabinet says so. Ask your pharmacist before you combine supplements and medicines.

Who should be careful

4 groups
Pregnancy and breastfeeding
No agency monograph covers kesum extract. NCCIH notes that many dietary supplements have not been tested in pregnant or nursing women, and no trial of this extract enrolled them.4
People on medicines
No drug-interaction data were found in ODS, NCCIH, LactMed, LiverTox, Health Canada or EMA sources. NCCIH advises telling your health care providers about any supplement, since supplements can interact with medicines.4
Before surgery
NCCIH notes that some supplements can raise bleeding risk or affect anesthesia, and advises telling the surgical team about every supplement in advance.4
Memory concerns
The trial enrolled people with mild cognitive impairment under study supervision; the evidence is too thin to substitute for a medical evaluation of memory changes.14
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.

Frequently asked questions

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

Common questions

5 answers
Does Persicaria minor improve memory?

One small six-month trial in older adults with mild cognitive impairment found better scores on one visual memory test but not on the other memory tests. It was funded by the extract maker, and no independent trial has repeated it.1

Is it safe?

No adverse events were reported in the 36-person trial, but no health agency has reviewed this extract, and safety in pregnancy, breastfeeding or with medicines is unknown.14

What dose was studied?

250 mg of the Biokesum water extract twice a day for 6 months.1

Is kesum the same as Polygonum minus?

Yes. Polygonum minus is the older botanical name for Persicaria minor, the herb called kesum in Malaysia.15

Why was the earlier study retracted?

The 2015 trial in 35 middle-aged women was retracted by Clinical Interventions in Aging in 2017. The retraction notice is indexed in PubMed; its results should not be relied on.23

Sources

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

Sources cited on this page

7 sources
  1. 1The effects of six months Persicaria minor extract supplement among older adults with mild cognitive impairment: a double-blinded, randomized, and placebo-controlled trial.RCT BMC Complement Med Ther, 2020 · PMID 33076878
  2. 2The effect of Polygonum minus extract on cognitive and psychosocial parameters according to mood status among middle-aged women: a randomized, double-blind, placebo-controlled study (RETRACTED).RCT Clin Interv Aging, 2015 · PMID 26445532
  3. 3The effect of Polygonum minus extract on cognitive and psychosocial parameters according to mood status among middle-aged women: a randomized, double-blind, placebo-controlled study [Retraction].Safety communication Clin Interv Aging, 2017 · PMID 29062226
  4. 4Using Dietary Supplements WiselyFact sheet National Center for Complementary and Integrative Health (NCCIH), 2019 · nccih.nih.gov
  5. 5Antioxidative and anti-inflammatory activities of Polygonum minus: a review of literature.Review Rev Cardiovasc Med, 2020 · PMID 32706215
  6. 6Persicaria minor ameliorates the cognitive function of chronic cerebral hypoperfusion rats: Metabolomic analysis and potential mechanisms.Animal study Behav Brain Res, 2023 · PMID 37030545
  7. 7Genotoxicity Evaluation of Biokesum® Polygonum minus (Persicaria Minor) Standardized Extract Using Bacterial Reverse Mutation, In Vitro Micronucleus, and In Vitro Chromosomal Aberration Studies.Lab study J Med Food, 2025 · PMID 40518833

What changed

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

Change log

2 entries
Dated changes to this page
DateChangeWho and why
research notesSearched PubMed (Persicaria minor, Polygonum minus, kesum, Biokesum) through 2026: no new human trial or meta-analysis; the 2020 trial (PMID 33076878) remains the only valid human trial. Added a 2025 lab genotoxicity study of the extract (PMID 40518833) to research notes, labelled as lab data. No ODS, NCCIH, LactMed, or LiverTox source covers this herb; interaction data remain absent, as the existing notes say.Writer: Kymata Health EditorialTrigger: A–Z page audit
allInitial editorial evidence reviewWriter: Kymata Health EditorialTrigger: new page

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