If your nails split before they even reach the tip of your finger, or your hair seems to stall at the same length no matter how long you wait, you're not imagining it — and you're not stuck with it. These are some of the most common signs that your body is running short on a few key nutrients it needs to build strong keratin. The good news is that both nail and hair growth respond well to targeted nutrition, and there's real research behind exactly which nutrients make the biggest difference. Here's what the science says about growing stronger nails and healthier hair, naturally.
What Nutrient Gaps Do to Your Hair and Nails
Hair and nails are both built mostly from keratin, a protein that needs a steady supply of specific nutrients to form properly. When those nutrients run low, the effects show up in ways that are easy to notice but easy to mistake for 'just genetics':
- Brittle, splitting nails that peel in layers or crack before they can be filed, often linked to low biotin or protein intake.
- Slow or stalled hair growth, where hair seems to plateau at the same length because more strands are shifting into a resting phase.
- Increased shedding during washing or brushing, frequently tied to iron or zinc levels that have dipped below optimal.
- Ridges or white spots on nails, which can reflect uneven keratin production during periods of nutrient stress.
- Dull, thin-feeling strands that lack the structural protein needed for thickness and shine.
1. Support Nail Firmness with Biotin
Biotin (vitamin B7) is a cofactor in keratin production, and it's one of the most studied nutrients for nail health specifically. In a widely cited case series, 71 patients with diagnosed brittle nail syndrome took 2.5 mg of biotin daily, and 41 of the 45 people followed up (91%) showed marked improvement in nail plate firmness after an average of about 5.5 months. A separate randomized 90-day study in 60 healthy women found nail growth was significantly greater in the group taking a biotin-containing multivitamin than in the placebo group. Biotin isn't a fast fix, but for weak, splitting nails, it's one of the better-studied places to start.
2. Try Collagen Peptides for Fewer Breaks and Faster Growth
Collagen supplies amino acids — like glycine and proline — that nails and hair use to rebuild their protein structure. In a randomized trial, 25 women with brittle nails took 2.5 grams of bioactive collagen peptides daily for 24 weeks, and researchers measured a 12% increase in nail growth rate and a 42% drop in the frequency of broken nails, with 64% of participants reporting overall improvement. Notably, the benefits were still present four weeks after supplementation stopped, suggesting collagen supports the nail matrix itself rather than just adding temporary moisture. Hair follicles rely on the same amino acid building blocks, which is why collagen is often paired with biotin and silica in hair-and-nail formulas.
3. Rule Out a Zinc Deficiency
Zinc supports the enzymes involved in protein synthesis and cell division — both essential for growing hair and nails. A cross-sectional study comparing people with diagnosed hair loss to a control group found significantly lower blood zinc levels in the hair loss group, reinforcing zinc's role as a common, correctable factor behind thinning and shedding. Because zinc needs are easy to fall short of on a restricted or plant-heavy diet, it's worth having your levels checked if hair or nail growth has slowed noticeably. Pairing zinc with copper, its natural counterbalance, helps avoid the mineral imbalance that can occur with zinc supplementation alone.
4. Check Your Iron Levels, Especially If You're a Woman
Iron acts as a cofactor for enzymes involved in DNA synthesis and cell proliferation inside the hair follicle, and multiple studies have linked low iron status to hair loss, particularly in women of reproductive age. Even iron levels that are 'low-normal' on a lab report, short of full anemia, have been associated with increased shedding in some research. If your hair has thinned gradually alongside fatigue, pale skin, or cold hands and feet, ask your doctor for a ferritin test rather than assuming it's purely genetic. A gentle, well-absorbed iron formula paired with vitamin C can help rebuild stores without the constipation that harsher iron supplements often cause.
5. Eat Enough Protein at Every Meal
Hair and nails are both built from protein, so chronic under-eating of protein shows up first in these tissues, which the body treats as less essential than organs and muscle. A recent systematic review of dietary factors and hair health found that overall protein intake, alongside micronutrient status, was consistently associated with hair growth and shedding patterns across the studies reviewed. Aiming for a source of complete protein — eggs, dairy, legumes, fish, or a quality protein powder — at each meal gives your body a steady stream of amino acids, rather than forcing it to prioritize which tissues get fed first.
Conclusion: Feed Your Nails and Hair From the Inside Out
Stronger nails and healthier hair rarely come from a single miracle ingredient — they come from consistently supplying the biotin, collagen, zinc, iron, and protein your body needs to build keratin properly. Give any new routine at least 3-6 months, since that's roughly how long these changes take to show up in visible growth. If you're looking for a simple place to start, explore our collagen range, formulated with bioactive collagen peptides alongside the nutrients your hair and nails need to rebuild from within.
