---
title: "If drugs can cross the lipid bilayer, why can't most drugs cross the blood-brain barrier?"  
description: "If drugs can cross the lipid bilayer, why can't most drugs cross the blood-brain barrier?"  
author: "Andy Simon"  
published: 2018-03-09  
canonical: https://answers.mindstick.com/qa/37831/if-drugs-can-cross-the-lipid-bilayer-why-can-t-most-drugs-cross-the-blood-brain-barrier  
category: "drug"  
tags: ["drug development"]  
reading_time: 1 minute  

---

# If drugs can cross the lipid bilayer, why can't most drugs cross the blood-brain barrier?

If drugs can [cross](https://answers.mindstick.com/qa/111025/what-is-the-international-red-cross) the lipid bilayer, why can't most drugs cross the blood-[brain](https://www.mindstick.com/blog/43411/do-video-games-affect-our-brain) barrier?


---

Original Source: https://answers.mindstick.com/qa/37831/if-drugs-can-cross-the-lipid-bilayer-why-can-t-most-drugs-cross-the-blood-brain-barrier

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