Taking Biotin? Here's What Your Doctor Might Want You to Know
It's in almost every hair gummy — and the FDA has issued warnings about it. Here's what many biotin users have never been told.
FDA safety communication
Biotin is in almost every hair, skin and nails product on the shelf — gummies, liquids, "high-potency" capsules. Millions of people take it every day without a second thought.
But there's something about biotin that many people have never been told — and it has nothing to do with hair.
The FDA has warned that biotin in supplements can interfere with certain lab tests and cause falsely high or falsely low results. In a 2019 update, the agency specifically flagged troponin tests — used to help diagnose heart attacks — where biotin can cause falsely low results.
Why does this happen?
Many common lab tests use biotin as part of how they work. When there's a lot of extra biotin in your blood, it can throw the test off. Thyroid tests and hormone tests have been affected too, depending on the lab method.
The issue isn't the tiny amount of biotin in food. It's the high doses found in many beauty supplements.
That's up to 333× the daily value — every single day.
What the FDA recommends
The FDA's advice is simple: tell your doctor about any supplements you take that contain biotin — including multivitamins and hair, skin and nails products — so the lab can take it into account. Don't stop or change any medication or supplement routine without talking to your doctor first.
And does all that biotin even help your hair?
Here's the part the labels don't mention: biotin deficiency is rare, and there's little evidence that extra biotin improves hair in people who aren't deficient. So many people are taking huge doses of an ingredient that may not be doing much — and that can complicate their lab work.
Look for a formula that skips the biotin and focuses on ingredients with a clearer role in hair — at doses you can actually see on the label.
Typical biotin hair product
- 5,000–10,000 mcg biotin
- Can interfere with lab tests
- Often a sugary gummy
- Doses often hidden
Denra Daily Density
- 0 mcg biotin
- No lab-test interference from biotin
- Sugar-free capsule
- All 11 doses on the label
Denra Daily Density
Daily Density was formulated without biotin on purpose. Instead it focuses on saw palmetto, palm-fruit tocotrienols, L-cystine, zinc + copper and vitamin D3 — every dose printed on the label.
- Zero biotin — nothing to flag before your next blood test
- 320 mg saw palmetto + 100 mg mixed tocotrienols
- No ashwagandha, no sugar, no proprietary blend
- 2 capsules a day, third-party tested
- Take it daily for at least 3 months for a fair test