Biotin: What It Really Does for Hair, Skin, and Nails

When you hear biotin, a B-vitamin also known as vitamin B7 that helps turn food into energy and supports skin, hair, and nail health. Also known as vitamin B7, it’s one of the most talked-about supplements in wellness circles. But here’s the thing—most people take it because they saw a celebrity post about shiny hair, not because they actually know what it does. Biotin isn’t magic. It doesn’t make hair grow faster out of nowhere. What it does is support the cells that build keratin, the protein your hair, skin, and nails are made of. If you’re deficient, biotin can help. If you’re not? It’s just expensive urine.

People often mix up biotin with other supplements like collagen or zinc, but they work differently. collagen, a structural protein that gives skin its elasticity and strength is about rebuilding tissue from the outside in. Biotin works from the inside out, helping your body use nutrients properly. Then there’s vitamin D, a hormone-like nutrient critical for immune function and cell growth, which many people are low on—and that can cause hair thinning too. So if your hair is falling out, it might not be biotin you’re missing. It could be vitamin D, iron, or even stress.

Real biotin deficiency is rare. It usually only happens with long-term raw egg consumption (yes, the raw egg thing is real—avidin in raw egg whites blocks biotin absorption) or certain genetic disorders. Most people get enough from food: eggs, nuts, salmon, sweet potatoes, and spinach. But if you’re taking biotin anyway, know this: it can mess with lab tests. Thyroid, heart, and hormone blood tests can show wrong results if you’re on high-dose biotin. That’s not a myth—it’s in the medical guidelines. One woman in Texas was almost misdiagnosed with a heart attack because her biotin supplement skewed her troponin levels.

So who should take it? If you have brittle nails that split easily, some small studies show biotin can help thicken them over time. Same with thinning hair—if it’s due to a real deficiency. But if you’re healthy, eating balanced meals, and your hair is just not as thick as you’d like? Biotin won’t fix it. You’ll spend money, get no results, and maybe accidentally ruin your next blood test.

The posts below cut through the noise. You’ll find real talk on supplements that actually matter, what science says about hair growth, and how to spot when a remedy is just hype. No fluff. No fake promises. Just what works—and what doesn’t—based on evidence, not Instagram ads.