Experts agree: “Your nails are made of proteins and naturally need a lot of vitamins,” Amy Lin, the founder of sundays, a nail care brand focused on wellness, once told us about how to strengthen nails. In fact, they’re made mostly of keratin. So while you can massage in a cuticle oil (as you should!) or commit to monthly maintenance, sometimes the best method for shiny, smooth nails is to go internal. That’s where we come in: Below, find the best vitamins for nails—including common ingredients to look for, as well as a curated list of supplements to choose from.* You know, in case you find yourself browsing the vitamin aisle. Biotin has been shown to support nail thickness and firmness2 in several human studies.* One moderate-size human study found that those who took biotin supplements had 25% thicker nail beds3 than the placebo group.* In supplements, it’s often paired with collagen to further support the skin and hair benefits.* These amino acids are the building blocks of nails—so if you provide your body with those nutrients, it will be better equipped to grow healthy, strong nails.* One study even found that when individuals took collagen daily for 24 weeks, it helped support their nail health4, including better growth rates, reduced breakage, and improved appearance.* In a way, it takes the middleman out of the equation—although, many options will still include keratin-building ingredients, like biotin and collagen, just to encourage your body’s natural production of the protein.* Vitamin E is another one to note, as research shows it can help support a healthy, fresh nail color5.* You might also reach for botanical antioxidants (like horsetail or fruit extracts) to protect the collagen you have from oxidative stress.* If you’re looking for specific supplements to add to your routine, consider one of the below. Each high-quality vitamin blend is formulated to target your hair, skin, and nail health.* Plus, save 10% on your first order with promo code MBG10. With these 8 options, you and your nails (and your skin and hair, while we’re at it) are covered.*