
Nail Strength & Growth
About this protocol
Where to start
Start with biotin at 2.5 mg (2500 mcg) daily. This is the one well-evidenced indication for biotin supplementation. Take note: if you''re going to have blood work done, stop biotin 72 hours prior — biotin interferes with many immunoassay-based lab tests (troponin, thyroid hormones).
Add silica (choline-stabilized orthosilicic acid form) for nail and hair thickness improvements. Effect builds over 20 weeks in trials.
Add hydrolyzed collagen peptides for nail growth rate and reduced peripheral breakage. Trials show improvements at 2.5-5 g daily over 24 weeks.
Consider iron ONLY if ferritin is confirmed low — chronic low iron causes brittle, ridged, spoon-shaped nails (koilonychia).
Expect 16-24 weeks before judging. Nails grow ~3 mm/month for fingernails; a full new nail takes ~6 months to grow out.
3 nutrients
Start here
Strongest evidence — the foundation of the stack.
Biotin (D-Biotin)
2500 mcg (2.5 mg) daily, with breakfastBiotin has trial evidence specifically for brittle nail syndrome. The Hochman 1993 trial in women with brittle nails showed measurable improvement in nail thickness and reduced splitting after 6 months at 2.5 mg/day. This is one of the few indications where high-dose biotin has real evidence — most other ''hair, skin, nails'' biotin uses are weak. CRITICAL: biotin at this dose interferes with troponin, thyroid hormone, and other immunoassay-based lab tests. Stop 72 hours before any blood work.[1, 2, 3]
Silica (Choline-Stabilized Orthosilicic Acid)
10 mg silicon daily, with breakfastSilica is a trace mineral involved in collagen and keratin cross-linking. The choline-stabilized orthosilicic acid form (BioSil) has trial evidence for improvements in nail brittleness, hair thickness, and skin elasticity over 20 weeks. Other forms (horsetail extract) have less consistent absorption.[4, 5, 6]
Add if needed
Add these only if the foundation isn't enough.
Hydrolyzed Collagen Peptides
2.5-5 g daily (anytime; can mix into coffee, smoothie, or water)Hydrolyzed collagen peptides have trial evidence for nail growth rate and reduced peripheral breakage. The Hexsel 2017 trial showed measurable improvements at 2.5 g/day over 24 weeks in women with brittle nails. Bovine and marine collagen both work; type I + III for keratinous tissues. Doses higher than 5 g/day don''t produce additional benefit for nail-specific endpoints.[7, 8]
Warnings
Lifestyle improvements
Protect nails from chronic water and chemical exposure
The single biggest reversible cause of brittle nails is chronic water exposure plus detergent/sanitizer use. Wear rubber gloves for dishes and cleaning. Apply nail oil daily.
Skip the bad manicures
Acetone-based polish removers, gel manicures with UV curing, dip powder removal, and aggressive cuticle cutting all damage nails. Consider extended breaks from polish — bare nails recover.
Adequate protein
Nails are keratin (a protein). Most women under-consume protein. 1.2-1.6 g/kg body weight daily supports nail and hair regrowth.
Hydrate the surrounding skin
Cuticle and nail-bed health depends on overall skin hydration. Daily nail oil (jojoba, vitamin E, or commercial cuticle oils) prevents the cracking that leads to peripheral nail breakage.
Iron status matters
Spoon-shaped nails (koilonychia) and brittle nails can signal low iron. Get a ferritin level if your nails have changed shape recently.
Patience
Nails grow ~3 mm/month. A full new nail takes ~6 months to grow out. Take baseline photos for comparison.
Consider seeing a dermatologist for persistent issues
Fungal infections, psoriasis, lichen planus, and several systemic diseases manifest as nail changes. A dermatologist can identify what supplements can''t fix.
References
- Biotin — supplement research overviewExamine.com link
- Hochman LG, et al. Brittle nails: response to daily biotin supplementation. Cutis. 1993;51(4):303-305.PubMed link
- Scheinfeld N, et al. Vitamins and minerals: their role in nail health and disease. J Drugs Dermatol. 2007;6(8):782-787.PubMed link
- Silicon — supplement research overviewExamine.com link
- Barel A, et al. Effect of oral intake of choline-stabilized orthosilicic acid on skin, nails and hair in women with photodamaged skin. Arch Dermatol Res. 2005;297(4):147-153.PubMed link
- Wickett RR, et al. Effect of oral intake of choline-stabilized orthosilicic acid on hair tensile strength and morphology in women with fine hair. Arch Dermatol Res. 2007;299(10):499-505.PubMed link
- Collagen — supplement research overviewExamine.com link
- Hexsel D, et al. Oral supplementation with specific bioactive collagen peptides improves nail growth and reduces symptoms of brittle nails. J Cosmet Dermatol. 2017;16(4):520-526.PubMed link
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Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This protocol is educational, not a substitute for personalized medical advice. Talk to your doctor before starting any new supplement regimen — especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition. Last updated 5/20/2026.