<p>Absorption half-life is approximately 25-50 hours and an elimination half-life of 5-20 minutes (progesterone gel) <sup class="text-reference-group"><a class="reference-popover-link" data-content="Progesterone gel: Crinone® 4% and Crinone® 8%" href="#reference-F3898">20</a></sup>. </p><p>Progesterone, administered orally, has a short serum half-life (approximately 5 minutes). It is rapidly metabolized to <em>17-hydroxyprogesterone</em> during its first pass through the liver <sup class="text-reference-group"><a class="reference-popover-link" data-content="Paulson RJ, Collins MG, Yankov VI: Progesterone pharmacokinetics and pharmacodynamics with 3 dosages and 2 regimens of an effervescent micronized progesterone vaginal insert. J Clin Endocrinol Metab. 2014 Nov;99(11):4241-9. doi: 10.1210/jc.2013-3937. Epub 2014 Feb 25. (PubMed ID 24606090)" href="#reference-A175657">11</a></sup>. </p>