<p>The protein binding of tamoxifen in plasma is over 98% and mostly to serum albumin.<sup class="text-reference-group"><a class="reference-popover-link" data-content="Lien EA, Solheim E, Lea OA, Lundgren S, Kvinnsland S, Ueland PM: Distribution of 4-hydroxy-N-desmethyltamoxifen and other tamoxifen metabolites in human biological fluids during tamoxifen treatment. Cancer Res. 1989 Apr 15;49(8):2175-83. (PubMed ID 2702659)" href="#reference-A182207">11</a></sup></p>