Download 2015 department of medicine research day

2015 DEPARTMENT OF MEDICINE RESEARCH DAY
Title of Poster: Unlabeled thyroid hormone content of nonprescription U.S. weight loss
products
Presenter: Angela M. Leung, MD, MSc
Division: Division of Endocrinology
☒Faculty ☐Fellow ☐Resident ☐Post-doc Research Fellow ☐Graduate Student ☐ Medical Student ☐Other
Principal Investigator/Mentor: Angela M. Leung, M.D.
M.W. Yeh, C.M. Rhee
Co-Investigators: C. D. Seger, X. He, L.E. Braverman,
Thematic Poster Category: Nutrition, Digestion and Metabolism
Abstract
Background: The U.S. Food and Drug Administration requires manufacturers of over-the-counter
(OTC) supplements to ensure the safety of their products, including increasingly popular
nonprescription weight loss aids. However, exogenous thyroid hormone, a medication prescribed to
individuals with hypothyroidism that, in excess, may result in thyrotoxicosis, has been found in OTC
supplements marketed for “thyroid support.” We hypothesize that OTC weight loss supplements also
contain measurable quantities of thyroid hormone (thyroxine (T4) and/or triiodothyronine (T3)) that
may be clinically significant.
Methods: Twenty-nine popular OTC weight loss supplements were measured for T4 and T3 content by
high performance liquid chromatography. Each reported value is the mean of duplicate measurements,
all of which differed by <15%.
Results: Nine (31%) of 29 products contained thyroid hormone. Five products (17%) contained only
T3, four (14%) contained both T4 and T3, and none contained only T4. Of the nine products
containing thyroid hormone, mean T4 content was 20.2±9.0 [SD] µg/day (n=4; range 9.6-29.6), and
mean T3 content was 22.4±21 [SD] µg/day (n=9; range 2.8-66.6) based on manufacturers’
recommended daily dosing.
Conclusion: Nearly one-third of sampled OTC U.S. weight loss products contain unlabeled thyroid
hormone in doses that may result in clinically significant thyrotoxicosis. Increased regulation is needed
to ensure the safety of consumers ingesting OTC weight loss products.