Not medical advice. I am a software engineer, not a physician. This page documents my own protocol and the research I read while building it. Talk to a qualified clinician before changing your supplementation, diet or any treatment. Lab reference ranges quoted here vary by laboratory and by individual.
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Horsetail (Equisetum arvense) is one of the oldest plants on Earth, dating back over 300 million years. It is the richest plant source of bioavailable silicon, containing up to 25% of its dry weight as silicic acid. Silicon is an essential trace element for connective tissue integrity: it strengthens hair shafts, hardens nails, and supports the collagen and elastin matrix of skin, tendons, and blood vessels. Horsetail has also been used traditionally for centuries as a natural diuretic for kidney and urinary tract health.
Horsetail vs. BioSil: Both provide silicon but in different forms. Horsetail delivers whole-plant silicon with additional minerals (potassium, manganese, flavonoids) and diuretic properties. BioSil delivers isolated ch-OSA with higher silicon bioavailability and stronger clinical validation. They can be used together for complementary silicon delivery.
| Parameter | Detail |
|---|---|
| Product | Nutricost Horsetail Extract 5,500 mg (extract equivalent), 240 Capsules |
| Dose | 1 capsule daily |
| Timing | With lunch |
| Rationale | Midday timing separates from morning supplements and avoids the diuretic effect interfering with sleep. Taking with food improves absorption. |
| Duration | 3-6 months for visible hair and nail improvements |
Diuretic note: Horsetail has a mild diuretic effect. Take earlier in the day (lunch, not dinner) to avoid nighttime urination. If you have kidney conditions or take diuretic medications, consult your physician before use. Stay well-hydrated.
Balch, P. A., et al. (2015). Use of silicon-based dietary supplement in alopecia: a systematic review. Dermatol Ther, 28(6), 362-366. PubMed 26610885
Jurkic, L. M., et al. (2013). Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: new perspectives for therapy. Nutr Metab, 10(1), 2. PubMed 22922415
Carneiro, D. M., et al. (2009). Mineral and phytochemical composition of Equisetum arvense. Food Chem, 115(2), 702-707. PubMed 19763940
A March 2025 study in the International Journal of Molecular Sciences investigated the protective effect of field horsetail polyphenolic extract on red blood cells and their membranes. The research demonstrated that Equisetum arvense extracts — rich in flavonoids, phenolic acids, and silica — significantly reduced lipid peroxidation and alleviated oxidative stress in cells, confirming potent antioxidant properties that extend beyond silicon delivery. Separately, a 2025 clinical trial found that a topical cream containing horsetail and soybean extracts reduced forehead wrinkles over 8 weeks, with 93.4% of participants (women aged 35–55) reporting visible improvements in wrinkle appearance, supporting horsetail's role in connective tissue and skin health.
| Test | Why It Matters | Details |
|---|---|---|
| Kidney Panel (BUN, Creatinine, eGFR) | Horsetail has diuretic properties that increase renal filtration. Monitor kidney function markers, especially with prolonged use or if you have pre-existing kidney conditions. | Lab Tests |
Nutricost Horsetail Extract 5,500 mg (240 Capsules) — $24.21
Concentrated extract equivalent to 5,500 mg of Equisetum arvense per capsule. Non-GMO, gluten-free. 240 capsules provides an 8-month supply.
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