Biotin-8 by Thorne

If you’re asking about biotin for hair and nails, this high-dose capsule fits people with brittle nails or confirmed low intake. It’s practical after bariatric surgery, with long-term anticonvulsant use (carbamazepine, phenobarbital, valproate), or if you’ve eaten raw egg whites regularly (avidin binds biotin). It’s also reasonable if your nails peel and split easily and other causes have been ruled out. For normal hair shedding without deficiency, biotin is often overhyped; address iron (Ferritin), thyroid (TSH), and Vitamin D, 25-Hydroxy first.

Biotin (vitamin B7) is a cofactor that turns on carboxylase enzymes, which help your cells use fats and carbohydrates for energy and build structural lipids. In nails and hair, it helps keratin infrastructure (the protein scaffold) function more reliably, which is why brittle nails often improve. Evidence for hair density is weaker than for nails, but nail firmness and thickness can improve within 2 to 4 months in responders. If nothing changes by 12 weeks, lack of deficiency is the usual reason.

Take one capsule daily, with or without food; some use two daily short term, then step down. This 8 mg dose is far above the daily requirement, which is why it’s used for brittle nails or suspected deficiency rather than routine maintenance. Expect nail changes within 8 to 12 weeks as the nail grows out. If you’re only after general upkeep, a lower microgram‑level biotin or a broad B‑complex is usually sufficient.

High‑dose biotin can skew many immunoassay lab tests. It can make thyroid results (TSH, Free T4), Troponin (the heart attack rule‑in test), PTH (parathyroid hormone), and some Vitamin D, 25‑Hydroxy assays look falsely high or low. Stop biotin 48 to 72 hours before planned bloodwork, and immediately tell urgent care or ER staff if you’ve taken it in the last few days. Anticonvulsants can lower biotin levels, which is one reason some patients supplement.

If you’re breaking out with new acne‑like bumps after starting high‑dose biotin, pause and retry at a lower dose. For unexplained hair loss, check Ferritin, TSH, and Vitamin D, 25‑Hydroxy rather than assuming biotin will fix it. Pregnancy and breastfeeding are generally compatible, but the lab interference still applies, so coordinate around prenatal tests. If you have a scheduled cardiac, thyroid, or endocrine workup soon, delay starting until after labs.

How long until nails improve? Plan on 2 to 4 months; nails grow slowly. Does it regrow hair? Not reliably unless you’re biotin‑deficient; rule out iron or thyroid issues first. Can I take it with a multivitamin? Yes—biotin doesn’t crowd out other B vitamins. Do I need it daily forever? No—once nails normalize, many step down to a lower dose or discontinue and monitor.