Polygonaceae
Water Pepper
Persicaria hydropiper
⚠ Use with Caution
Avoid in Pregnancy
Native to: Europe, Asia, North America
Also known as: Smartweed, Biting Persicaria, Marshpepper Knotweed, Arse-smart
Wikimedia Commons / CC BY-SA
Parts Used
Aerial parts
Therapeutic Uses
Excessive menstruation (haemostatic), diarrhea, hemorrhoids, bruising. Traditional hemostatic herb — less commonly used than shepherd's purse.
Herbal Actions
Haemostatic (astringent), emmenagogue, antidiarrheal, diuretic, antifungal
Active Constituents
Tannins, flavonoids (persicarin, quercetin), acrid principles (polygodial — biting taste), essential oil, rutin, oxalic acid
Preparation Methods
🏺 Tincture☕ Herbal Tea
Traditional Preparation Notes
| Herbal Tea | 1–2 tsp dried herb per 250ml, steep 10 min, 3x daily |
| Tincture | 2–4 ml (1:5, 25% ethanol), 3x daily |
| Notes | Less potent haemostatic than shepherd's purse but useful alternative. Combine with yarrow and lady's mantle for menorrhagia. Topical: apply to bruises. |
Safety Information
Safety Rating
⚠ Use with Caution
Pregnancy
Avoid in Pregnancy
Drug Interactions
None known
Contraindications: Avoid in pregnancy (emmenagogue). Caution in kidney disease (oxalates).
Side Effects: Skin irritation (acrid polygodial). GI irritation. Photosensitivity. Oxalate kidney effects.