Category: Health science

By definition, a drug administered intravenously (IV) has 100% bioavailability, meaning it enters the bloodstream almost instantly [1.6.1, 1.6.3]. The question of *how long does it take for something to get into your bloodstream* for all other methods depends entirely on the route of administration and other key factors.

The human skin, our body's largest organ, is a highly effective protective barrier designed to keep external substances out. However, a common misconception is that all creams readily absorb into the bloodstream, a process that is far more complex and selective than many believe. This article explores how and when cream ingredients can be absorbed, focusing on the key differences between topical and transdermal formulations and the factors that influence their pharmacological action.

In the United States, nearly half of all people have used at least one prescription drug in the past 30 days [1.9.1]. A common question among them is, **how long does it take for a small pill to kick in?** The answer typically ranges from 20 minutes to over an hour [1.2.1].

Global medicine use grew by 14% between 2018 and 2023 and is expected to increase another 12% by 2028 [1.9.2]. But beyond this widespread use, what is the main function of medicine? The answer is multifaceted, extending beyond simply treating sickness.

In 2024, the number of retail prescriptions filled in the U.S. reached 4.9 billion, with each medication relying on a specific biological process to produce its effect [1.8.1]. But what are the 4 categories of drug action that fundamentally govern how these substances interact with our bodies at a molecular level?