It is nice to contemplate being a deep woods alchemist and manufacturing all sorts of useful products from scratch. There is a certain pride you can get from making your own and coaxing beneficial compounds from raw materials you collected yourself.

But the simple fact is that $4 gets you a 1000 count bottle of generic aspirin. Weeks of dedicated hard work would get you a tenth as much and half as effective.

Bathtub chemistry is labor, material and equipment intensive, time consuming and often hazardous. In a survival situation time, materials and energy are often in short supply so it is often better to just plan ahead and stock up on what you need.

I'm not discouraging anyone from having a go at making your own or being a backyard chemist but you have to keep it in context of what your hoping to gain and how much it costs you.