🌾Vietnamese Traditional Medicine

Drynaria Fern (Tắc Kè Đá)

Drynaria roosii

About Drynaria Fern (Tắc Kè Đá)

Drynaria Fern (Tắc Kè Đá) (Drynaria roosii) is a herb used in the Vietnamese Traditional Medicine tradition to help with Bone Health, Back Pain, Kidney Support, and Arthritis. The aerial parts and leaves are the parts traditionally used, taken internally.

Botanical background

Drynaria roosii, commonly known as gu-sui-bu, is a species of basket fern of the family Polypodiaceae. The plant is native to Eastern Asia, including eastern China.

Source: Wikipedia, via iNaturalist

Parts used

Aerial Parts · internalLeaves · internal
🍵

Tea / Infusion

1–3 cups daily
  • Steep 1–2 tsp of dried Drynaria Fern (Tắc Kè Đá) 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 Drynaria Fern (Tắc Kè Đá) 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 Drynaria Fern (Tắc Kè Đá) into a fine powder.
  • Fill size 00 capsules or stir into smoothies or honey.
🖐️

Topical / Poultice

1–2× daily as needed
  • Mash fresh Drynaria Fern (Tắc Kè Đá) 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 Drynaria Fern (Tắc Kè Đá).
  • 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 Drynaria Fern (Tắc Kè Đá) in 1 litre of hot water for 15 minutes, strain, and add to a warm bath.
  • Soak for 20–30 minutes.

Contraindications

  • Pregnancy & breastfeeding — insufficient safety data; consult your doctor
  • Children under 12 — therapeutic dosage not established
  • Significant kidney impairment — diuretic herbs may worsen renal function

Warnings

⚠️ Pregnancy & Breastfeeding

Safety during pregnancy and breastfeeding has not been established for most herbal remedies. Consult your midwife or doctor before use.

⚠️ Kidney Disease

Some diuretic herbs are contraindicated in those with kidney disease. Consult your doctor if you have impaired kidney function.

⚠️ 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

May have a diuretic effect

Watch for: Diuretic medications and lithium

Additive fluid loss can affect electrolyte balance and change how the body clears lithium.

Where to find in nature

Native region

Vietnam, southern China

Climate

Tropical to subtropical

Habitat

Tropical forests, rice paddy borders, and village herb gardens of Vietnam

🌿 To see Drynaria Fern (Tắc Kè Đá) 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 Drynaria Fern (Tắc Kè Đá), 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.