🏯Khmer Traditional Medicine

Siam Weed (Chi Prey)

Chromolaena odorata

About Siam Weed (Chi Prey)

Siam Weed (Chi Prey) (Chromolaena odorata) is a herb used in the Khmer Traditional Medicine tradition to help with Wound Healing, Fever, Skin Health, and Antimicrobial, among 1 other condition it addresses. The aerial parts and leaves are the parts traditionally used, used both internally and topically.

Botanical background

Chromolaena odorata is a tropical and subtropical species of flowering shrub in the sunflower family. It is native to the Americas, from Florida and Texas in the United States south through Mexico and the Caribbean to South America. It has been introduced to tropical Asia, west Africa, and parts of Australia. Common names include Siam weed, Christmas bush, devil weed, camfhur grass, common floss flower and triffid.

Source: Wikipedia, via iNaturalist

Parts used

Aerial Parts · bothLeaves · both
🍵

Tea / Infusion

1–3 cups daily
  • Steep 1–2 tsp of dried Siam Weed (Chi Prey) in freshly boiled water for 5–10 minutes.
  • Cover while steeping.
  • Strain and drink.
💧

Tincture

20–40 drops in water, 2–3× daily
  • Pack dried Siam Weed (Chi Prey) into a jar and cover with 40–60% alcohol.
  • Seal and steep for 4–6 weeks, shaking daily.
  • Strain and store in a dark dropper bottle.
💊

Powder / Capsule

500 mg – 1 g, 1–3× daily
  • Grind dried Siam Weed (Chi Prey) into a fine powder.
  • Fill size 00 capsules or stir into smoothies or honey.
🖐️

Topical / Poultice

1–2× daily as needed
  • Mash fresh Siam Weed (Chi Prey) or mix the powder with a little water to form a paste.
  • Apply to the affected area for 20–30 minutes.
🫙

Infused Oil

Massage into affected area 1–2× daily
  • Fill a jar with dried Siam Weed (Chi Prey).
  • Pour over a carrier oil until submerged.
  • Leave for 4–6 weeks, then strain.
  • Use topically or as a salve base.
🛁

Herbal Bath

2–3× per week as needed
  • Brew 4–6 tbsp of Siam Weed (Chi Prey) in 1 litre of hot water for 15 minutes, strain, and add to a warm bath.
  • Soak for 20–30 minutes.

Pregnancy, Breastfeeding & Children

No herb-specific pregnancy/child safety research is documented for Siam Weed (Chi Prey) in our references — the guidance below is based on its general effect category, not research on Siam Weed (Chi Prey) itself. Always confirm with a midwife, doctor, or pediatrician.

Pregnancy

Insufficient Data

No specific pregnancy safety research is documented for this herb in our references. This doesn't mean it's unsafe — it means it hasn't been well studied. Treat as unstudied and avoid unless a midwife or doctor familiar with your pregnancy advises otherwise.

Breastfeeding

Insufficient Data

No specific breastfeeding safety research is documented for this herb in our references. Treat as unstudied and consult a lactation consultant, midwife, or doctor before use.

Children

Insufficient Data

No specific pediatric safety/dosage research is documented for this herb in our references. Treat as unstudied and consult a pediatrician or pediatric herbalist before giving to a child.

Contraindications

    Warnings

    ⚠️ Allergic Reactions

    Discontinue immediately if you experience rash, itching, swelling, or difficulty breathing.

    ⚠️ Not Medical Advice

    This information is for educational purposes only. Always consult a qualified healthcare provider before using herbal remedies.

    Drug & herb interactions

    No specific drug or herb interactions are documented for Siam Weed (Chi Prey) in our references. This doesn’t mean none exist — always check with a pharmacist or doctor before combining any new herb with prescription medication.

    Where to find in nature

    Native region

    Various global regions

    Climate

    Varied

    Habitat

    Cultivated in traditional medicinal gardens, botanical gardens, and herb farms worldwide

    🌿 To see Siam Weed (Chi Prey) growing, visit botanical gardens, university plant collections, or specialist herb nurseries near you. If foraging in the wild, always work with an expert identifier — never consume a plant you are not 100% certain of.

    Where to buy

    In store

    • Health food stores (Whole Foods, Natural Grocers, Holland & Barrett, GNC)
    • Naturopathic clinics and integrative medicine practices
    • Specialist herbal apothecaries and herbalist practices
    • Farmers markets with herb vendors

    Online

    iHerb

    Wide selection of standardised extracts, capsules, and powders with lab testing

    Mountain Rose Herbs

    Premium bulk dried herbs — certified organic, ethically sourced

    Starwest Botanicals

    Large selection of certified organic bulk herbs and powders

    Herb Pharm

    High-quality liquid extracts and tinctures, rigorous quality standards

    Amazon

    Convenient — verify brand certifications and check third-party testing

    Etsy

    Small-batch artisan herbalists, hand-harvested and wildcrafted herbs

    Quality tips

    When buying Siam Weed (Chi Prey), look for: certified organic labelling, clearly stated country of origin, third-party lab testing for heavy metals and pesticides, and a batch expiry date. Standardised extracts offer consistent dosing; bulk dried herbs are more economical for regular use. Avoid very cheap, unlabelled products — quality varies enormously.