⛩️Kampo / Japanese Medicine

Phellodendron (Obaku)

Phellodendron amurense

About Phellodendron (Obaku)

Phellodendron (Obaku) (Phellodendron amurense) is a herb used in the Kampo / Japanese Medicine tradition to help with Inflammation, UTI, Diabetes, and Skin Health. The aerial parts and leaves are the parts traditionally used, used both internally and topically.

Botanical background

Phellodendron amurense is a species of tree in the family Rutaceae, commonly called the Amur cork tree. It is a major source of huáng bò (Chinese: 黄柏 or 黄檗), one of the 50 fundamental herbs used in traditional Chinese medicine. The Ainu people used this plant, called shikerebe-ni, as a painkiller.

Source: Wikipedia, via iNaturalist

Parts used

Aerial Parts · bothLeaves · both
🍵

Tea / Infusion

1–3 cups daily
  • Steep 1–2 tsp of dried Phellodendron (Obaku) 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 Phellodendron (Obaku) 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 Phellodendron (Obaku) into a fine powder.
  • Fill size 00 capsules or stir into smoothies or honey.
🖐️

Topical / Poultice

1–2× daily as needed
  • Mash fresh Phellodendron (Obaku) 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 Phellodendron (Obaku).
  • 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 Phellodendron (Obaku) 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 Phellodendron (Obaku) in our references — the guidance below is based on its general effect category, not research on Phellodendron (Obaku) itself. Always confirm with a midwife, doctor, or pediatrician.

Pregnancy

Use Caution

This herb may affect blood sugar levels. Given the importance of stable glucose control in pregnancy, herbs in this category are generally used only under medical guidance, particularly alongside any gestational diabetes monitoring — this is a general, mechanism-based caution, not herb-specific research.

Breastfeeding

Use Caution

Generally used cautiously during breastfeeding, particularly if managing blood sugar medically.

Children

Use Caution

Children are more sensitive to blood-sugar swings given their smaller body size — these herbs are generally used cautiously and under guidance.

Contraindications

  • Significant kidney impairment — diuretic herbs may worsen renal function
  • Diabetes medications — may enhance hypoglycaemic effect; monitor blood glucose closely

Warnings

⛔ Diabetes Medications

May enhance the blood sugar–lowering effect of insulin or oral diabetes medications. Monitor blood glucose closely.

⚠️ 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.

May affect blood sugar

Watch for: Insulin and oral diabetes medications (metformin, sulfonylureas)

Additive blood-sugar-lowering effects can risk hypoglycemia — monitor glucose closely.

Where to find in nature

Native region

Japan, China, Korea

Climate

Temperate to subtropical

Habitat

Mountain forests and cultivated herb farms across Japan and East Asia

🌿 To see Phellodendron (Obaku) 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 Phellodendron (Obaku), 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.