I know this bugs a lot of people. I use stimpacks as currency when merchants run out of caps so I could care less, but today the reasons hit me.
Why does a herbal remedy beat our pre-war science?
Well lets consider the label of any medicine bottle. First it has an expiration date, normally 1 year, after which it begins to lose potency. FO NV takes place over 200 years after that expiration date so the drug is a lot weaker. Most drugs also need to be kept at certain temperatures, and without air conditioning and heat that probably went away a long time ago. Now throw in radiation, possible moisture, being stepped on by a radroach a few times and I'm surprised injecting a stimpack in your arm doesn't instantly kill you.
Now its possible to recreate many of the drugs. You can make stimpacks, and the Khans make everything that is 'fun'. When you make a stimpack you are using the same ingredients in healing powder. You are just making healing powder that can be injected for better results... thats it. Something tells me pre war stimpacks had more sophistication and different ingredients. The broc flower stimpacks you make are just comparable to stim packs that expired 200 years ago. The same can be said for the drugs that the Khans make. The original buffout probably had a better effect and less side effects than it does now after two hundred years, or a version cooked up in a meth lab. Speaking of meth labs many illegal drugs cooked up in meth/crack labs are close cousins to prescription drugs made in science labs. The buffout made by the khans is likely a bastardized version of what it was pre war with similar effects.
In addition most of our medicines come from plants. Almost all of our painkillers come from plants. Many of our medicines are poisons used in a way that is beneficial. Look up the active ingredient in Botox for instance. If memory serves its a couple thousand times more toxic than some of the most toxic chemical weapons, and it makes the traditional scary animal venoms look like soda water. Yet we inject it directly into people's faces to make them look pretty. That's either really stupid or really impressive... not really sure yet. I bring this up because the plants and animals in the FO universe got a major overhaul. Maybe a broc flower does have super healing capabilities that rival old war tech. The mutated plants and animals could very well have medical uses that exceed what they had before the bombs.
The one thing I can't answer is why you can't use a high medicine & survival skill to make better medications using the things you know from survival. If a stimpack is a liquid healing powder I want a liquid injectable wasteland omelet!
Thoughts?