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Citrus hystrix

Makrut lime

Generally recognised as safe

Other names: Thai lime, Makrut lime leaf

A tropical citrus with knobby fruits; the aromatic leaves star in Thai cooking.

An evergreen thorny shrub to small tree with distinctively winged leaves and small rough fruits; Thai and Indonesian cooking uses mainly the glossy fragrant leaves and the fruit zest.

Family
Rutaceae
Plant type
Evergreen shrub/tree
What the safety levels mean (expand legend)
  • Generally recognised as safe. Often a common herb with reasonable harvest and use; still read the specific warnings on the card.
  • Information. Primarily informational — details in the text and warnings below matter most.
  • Caution. Needs extra care (dose, duration, sensitive groups, interactions).
  • Risky. Significant risks — verify sources, contraindications and professional guidance.
  • Not for home experimentation. Not suitable to experiment with at home without knowledge and certainty.
  • High risk for internal use. Particular risk with internal use (e.g. alkaloids); avoid prolonged or irresponsible dosing.
  • Not specified. Level not filled in yet — rely on individual warnings and links below.
Makrut lime — plant habitus (Wikimedia Commons).

Photograph on Wikimedia Commons (CC BY-SA 3.0).

Plant habit

Quick overview

A practical summary; details are in the sections below.

Safety grade
Generally recognised as safe details
Scientific sources on the card
Yes — sources are listed with claims Science section
When and what to harvest
  • Leaf — January–December
  • Fruit — January–December
Full harvest section
Processing methods

Culinary use, Essential oil and more

All methods and recipes on the card
Topics and symptoms

Creativity & inspiration, Digestion, Scalp & hair…

Topics section, Symptoms overview

Identification and mix-ups

Spiny shrub to tree in Rutaceae about 3–6 m, with spines on the branchlets. The leaves are diagnostic: glossy dark-green, double (hourglass-shaped), formed of a blade plus a broad winged petiole nearly the size of the blade; highly aromatic. Fruit small (about 5–7 cm), with a distinctly warty, knobby rind, thick, green ripening yellow; juice scant and very acidic.

Possible mix-ups and risks

Confused with Citrus micrantha (Philippine papeda), a close relative possibly conspecific; the genomic distinction is not definitively resolved. Other papeda-group species also have winged petioles but lack the combination of heavily warty fruit and figure-eight leaf. It is not toxic.

Similar herbs

No related herbs are linked yet.

Topics and symptoms

More topics are in the symptoms and topics overview.

Sources

Geographic occurrence

  • Thailand

    Common (expected wild occurrence in the region)

Harvest

  • LeafJanuary–December

    year-round

    Region: Thailand

    Notes: Glossy fragrant leaves and the rough zest of ripe fruits.

  • FruitJanuary–December

    year-round

    Region: Thailand

    Notes: The knobbly fruits are picked all year in the tropics, most in the rainy season; they are taken green, when the rind holds the most oil. The pulp is sour and bitter; the rind and juice are used.

Storage

  • Refrigeration(Leaf)

    Fresh leaves keep 2 weeks in the fridge in a bag; frozen 6 months without losing scent — freezing beats drying, dried leaves smell faint. Fruits 2 weeks in the fridge, grated rind frozen.

    Moisture:
    Pat dry before storing.

Processing methods on this herb card

  • Culinary use(Leaf)Suitability: High suitability

    Cooking, baking, seasoning as food — general category without therapeutic claims.

    Full method description (from the catalogue)

    Culinary use covers herbs as ingredients in dishes, drinks, or spice mixes. This overview does not evaluate medicinal effects — only reminds you about species intent, allergies, and heat treatment where needed (e.g. some fruits or plant parts).

    Combining with alcohol, sugar, or long cooking changes outcomes; verify culinary sources.

    Traditional context for this method: yes·Scientific context for this method: no

    Tom yum with makrut lime leaves

    About 30 minBeginnerScience profile

    Open recipe →

  • Culinary use(Fruit)Suitability: Medium suitability

    Cooking, baking, seasoning as food — general category without therapeutic claims.

    Full method description (from the catalogue)

    Culinary use covers herbs as ingredients in dishes, drinks, or spice mixes. This overview does not evaluate medicinal effects — only reminds you about species intent, allergies, and heat treatment where needed (e.g. some fruits or plant parts).

    Combining with alcohol, sugar, or long cooking changes outcomes; verify culinary sources.

    Traditional context for this method: yes·Scientific context for this method: no

  • Essential oil(Leaf)Suitability: Low suitability

    A concentrated aromatic plant product; use depends on the specific product.

    Full method description (from the catalogue)

    Essential oil is a concentrated plant product obtained, for example, by steam distillation or pressing. A general drop count or dilution ratio does not establish safe use.

    Choose a finished product intended for your purpose and follow its directions. Do not apply it to skin or swallow it unless the manufacturer explicitly allows that use. This overview is not a recipe for home dilution.

    Traditional context for this method: no·Scientific context for this method: no

    The oil from the leaves (citronellal) and from the rind is distilled industrially for the fragrance industry. Dilute on the skin; citrus rind oils can irritate.

Traditional / spiritual use

Kept separate from science — entries are cultural or symbolic, not medical advice.

  • The fruit that washes away bad luck

    General

    Spiritual useFolk useRitualSuperstition

    In Thailand makrut limes are cut into water that a monk or a family elder blesses (nam mon), and a person washes with it after an accident, a funeral or a run of bad luck — the sour juice and strong scent are meant to carry off ill influences. The same juice has served for centuries as a shampoo and hair rinse against dandruff, and in Malay tradition the fruit goes into a newborn's bath. A record of ritual and folk practice.

    Form:
    fruit in blessed water; juice as a traditional shampoo
    Claim strength:
    Tradition
    Source note:
    Agouillal F et al. (2017), Biosci Biotechnol Res Asia 14:285–305 (ethnobotany); Thai folk practice (sadoh khro, nam mon).

Scientific notes

Each claim lists a study type and a source (URL or DOI) where available. Dose notes from the literature are informational only.

How to read evidence strength and study type labels

Labels summarise how the catalogue entry is tagged — they are not a medical verdict on efficacy. For every row, read the summary, limitations and source link.

Evidence strength

Evidence level not specified
The author did not grade the record; judge from the summary, limitations and source link.
Narrative / orientational literature
Descriptive or expert literature without controlled group comparison — context rather than proof of effect.
Weak evidence
Study or conclusion with major methodological limits; treat only as a pointer for further reading.
Preliminary findings
First or smaller studies — interesting direction, not the final word on efficacy or safety.
Moderate strength of evidence
Moderate strength by study design; sample and context limits still apply.
Stronger evidence
Stronger design or consistency of results within the study's stated limits.
Review article
A review summarises multiple sources; quality depends on review method and field.

Study type

Narrative / expert text
Expert text or overview without a classical study design.
In vitro study
Cell culture or test-tube experiment — does not show an effect in the body.
Animal study
Animal model — transfer to humans is not automatic.
Observational study
Observing groups without random treatment assignment; confounding is possible.
Clinical trial
Human clinical trial; sample size and control group matter.
Randomised controlled trial
Randomised controlled trials are among the stronger designs when well conducted.
Review study
A review aggregates multiple papers — quality depends on selection rules.
Systematic review
Systematic review with explicit search and selection methodology.
Meta-analysis
Statistical pooling of studies; outcome depends on input data and heterogeneity.
Regulatory assessment / monograph (EMA, WHO…)
Regulatory body summary for a herbal product — different context from a single RCT; often about products, not home tea.
Expert monograph (herbal preparations)
Structured literature summary for a plant or drug — quality depends on author and edition year.

  • The review summarises the taxonomy, the composition of the leaf oil (citronellal, citronellol, linalool) and rind oil (beta-pinene, sabinene, limonene), coumarins and flavonoids, and laboratory data on antimicrobial, antioxidant and insecticidal activity; clinical trials are lacking.

    Narrative / orientational literatureReview studyYear: 2017

    Limitations: Preclinical data; a journal with weaker quality control.

    Agouillal F, Taher ZM, Moghrani H, Nasrallah N, El Enshasy H — Biosciences Biotechnology Research Asia

    A Review of Genetic Taxonomy, Biomolecules Chemistry and Bioactivities of Citrus hystrix DC

    DOI: 10.13005/bbra/2446

Images

The main photo is in the card header. More images will appear here when available.

Safety

What the warning types mean

The type on each warning helps group themes — it does not replace the separate severity badge.

Internal use
Risks from swallowing, extracts, duration of use or concentration for internal use.
Interactions / medicines
Possible effect on medicines or concurrent treatment — check sources and a professional.
Raw plant parts
Raw, unripe or poorly prepared plant parts can be dangerous.
Toxins and regulation
Toxic constituents or regulated compounds (e.g. in distillates).
Contact with the plant
Skin or mucosa irritation from contact with fresh plant or sap.
Allergy
Allergic reactions, often linked to family sensitisation.
Harvesting and contamination
Contamination, species mix-ups or harvesting from unsuitable places.

No structured safety records yet.