0
hair

Horsetail

Equisetum arvense

木贼

Pinyin: Mù Zéi

🌿

Plant Family

Equisetaceae

Part Used

Aerial parts (sterile stems)

Origin

Europe, Asia, North America; grows worldwide in moist areas

Safety Level

Caution

Overview

Horsetail is a prehistoric plant that has survived since the time of the dinosaurs. It gets its name from its brush-like appearance resembling a horse's tail. Horsetail is best known for its extremely high silica content, which makes it valuable for skin, hair, nail, bone, and connective tissue health. It has been used as both medicine and an abrasive (for polishing metal and wood).

Traditional Chinese Medicine Properties

Nature (四气)

cool

Flavors (五味)

bitter, astringent

Meridians (归经)

kidney, bladder, lung

Health Benefits

✓ High silica content supports healthy hair, skin, and nails
✓ May promote hair growth and reduce hair thinning
✓ May strengthen nails and reduce brittleness
✓ Bone health (silica is important for bone formation and collagen synthesis)
✓ May help with osteoporosis (in combination with calcium - some research)
✓ Diuretic effect (increases urine output)
✓ May help with urinary tract infections (mild antimicrobial)
✓ Wound healing and tissue repair (topical)
✓ May help with brittle bones and connective tissue issues

Traditional Uses

  • Strengthen hair, skin, and nails (silica content)
  • Bone health and fracture healing
  • Diuretic and kidney/bladder support
  • Wound healing and stop bleeding
  • Osteoporosis prevention
  • Brittle nails
  • Rheumatoid arthritis and joint health

Active Constituents

The key compounds responsible for this herb's therapeutic effects:

Silica (silicon dioxide - up to 10% dry weight - primary active)Flavonoids: quercetin, kaempferol, luteolinSaponins: equisetoninAlkaloids: nicotine (small amounts), palustrinePhenolic acids: caffeic acid, ferulic acidTanninsMinerals: calcium, potassium, magnesium, manganeseAmino acids

Usage & Dosage

How to Use

Tea, tincture, capsule, powder, hair rinse (topical), bath herb, poultice.

Suggested Dosage

Tea: 1–2 tsp dried herb per cup, 2–3x/day; tincture: 2–3 mL 2–3x/day; capsules: 300–500 mg 2–3x/day. Hair rinse: strong tea applied after shampooing. Use in cycles (e.g., 6 weeks on, 2 weeks off).

Quality & Storage

Harvest Season

Sterile stems harvested in late spring to early summer (May–July), before spore-bearing fertile stems appear. Harvest on a dry day. Only use sterile (green, feathery) stems - avoid fertile stems.

Quality Indicators

Dried herb: green to gray-green, slender segmented stems, slightly grassy odor. Should be harvested from clean areas away from polluted water. Look for products that have been heat-treated or processed to reduce thiaminase content. Quality varies - ensure it's from a reputable source.

Storage

Airtight container in cool dark place. Dried herb lasts 1–2 years. Protect from moisture. Horsetail can absorb moisture from the air.

Safety Information

Contraindications

Pregnancy and breastfeeding (avoid)Heart failure or severe kidney disease (diuretic and potassium effects)Low potassium levels (thiaminase may increase risk)Alcoholism (thiaminase destroys thiamine - worsens deficiency)Children (nicotine content and thiaminase - not recommended for long-term use)Do not use fresh horsetail (higher thiaminase content - use dried or processed)Thiamine (vitamin B1) deficiency

Possible Side Effects

  • Generally safe for short-term use (2–4 weeks)
  • Long-term use may cause thiamine (vitamin B1) deficiency (due to thiaminase enzyme - most commercial products are processed to reduce this)
  • May cause potassium deficiency with long-term use
  • Digestive upset (nausea, diarrhea) in high doses
  • Allergic reaction (rare)
  • Kidney irritation with excessive use
  • Nicotine-like effects in very high doses (rare)

Drug Interactions

  • Diuretics and water pills (additive effect)
  • Lithium (may increase levels)
  • Digoxin (may increase risk due to potassium loss)
  • Thiamine supplements (thiaminase destroys thiamine)
  • Alcohol (worsens thiamine deficiency)
  • Corticosteroids (potassium loss)
  • Moderate interaction potential with long-term use

Note: Always consult with a qualified healthcare practitioner before starting any herbal supplement, especially if you are pregnant, nursing, have medical conditions, or take medications.

References & Research

Information on this page is based on traditional herbal knowledge and modern scientific research. For a comprehensive list of references, please refer to our full citations page.

ℹ️ Disclaimer

This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. The FDA has not evaluated these statements. Always consult a qualified healthcare provider before using herbal supplements.

Related Herbs

He Shou Wu (Fo-Ti)

Polygonum multiflorum

He Shou Wu is one of the most famous longevity herbs in TCM, known for restoring hair color and vitality. The prepared (red) form is used for tonification.

Biotin (Vitamin B7)

Biotin (Vitamin B7 / Vitamin H)

Biotin, also known as vitamin B7 or vitamin H, is a water-soluble B vitamin that plays a crucial role in energy metabolism and the health of hair, skin, and nails. It acts as a coenzyme in several important metabolic processes. Biotin is often called "the beauty vitamin" because of its well-known effects on hair, skin, and nail health. While true biotin deficiency is rare, many people supplement with biotin for cosmetic benefits.