If you are taking sneaky Biotin tell your doctor before they do blood tests

Barbesino G. Misdiagnosis of Graves' disease with apparent severe hyperthyroidism in a patient taking biotin megadoses. Thyroid. 2016 Apr 4. [Epub ahead of print]

BACKGROUND:Accurate immunoassays measuring minute quantities of hormones are the cornerstone of the practice of endocrinology. Despite tremendous advances in this field, novel pitfalls in these tests emerge from time to time. Oral biotin can interfere with immunoassays of several hormones. The purpose of this report is to relate an extreme case of such interference.
PATIENT FINDINGS: A patient with progressive multiple sclerosis was found to have extremely elevated free thyroxine (FT4), triiodothyronine (T3) and suppressed thyrotropin (TSH) levels. His TSH receptor binding inhibiting antibody (TBII) level was also elevated. This constellation of laboratory findings suggested a diagnosis of severe Graves' disease. All of the assays yielding abnormal results employed the biotin-streptavidin affinity in their design. The patient had no symptoms of hyperthyroidism and detailed review of his medications revealed intake of megadoses of biotin. Temporary discontinuation of biotin treatment resulted in complete resolution of the biochemical abnormalities.
CONCLUSIONS: Non-physiologic biotin supplementation may interfere with several immunoassays, including thyroid hormones, TSH, thyroglobulin (Tg) and TBII leading to erroneous diagnoses. Questioning for biotin intake should be part of the evaluation for patients undergoing endocrine tests. Interruption of biotin supplementation for at least 2 days prior to biotin-sensitive tests should be sufficient to avoid major misdiagnoses.


High dose Biotin is currently being investigated for progressive MS. Whilst you don't have access to these experimental pills, for a few dollars you can buy enough low biotin content pills from the health food shop for a fraction of the cost. So whilst you may be rattling from taking so many pills, make sure you don't get your thyroid removed in the process.

In this study the person was doing just this and went for a blood test, but because the test uses a molecule called streptavidin that binds to biotin there was a false positive signal in their blood test. This said there was an over active thyroid. Your doctor will act on these results, so be warned. If you are taking biotin, you should tell your doctor if they are going to do blood tests and if you are a doctor and get usually high results maybe ask the question "Areyou taking biotin?" You should stop doing this before any blood test...why waste your and the neuros time. 

Biotin, also known as vitamin H, is a small molecule that is present in tiny amounts in all living cells and is critical for a number of biological processes. The valeric acid side chain of the biotin molecule can be used to attach biotin to other molecules. In the context of immunostaining and bomarker stuff, biotin is conjugated to antibodies or to the enzyme reporters used to detect target antigens.

The extraordinary affinity of avidin for biotin allows biotin-containing molecules in a complex mixture to be specifically bound to avidin.  It contains four identical subunits and binds one molecule of biotin; thus, a total of four biotin molecules can bind to a single avidin molecule. This is used in bioassays for detecting hormones.