Shortly after I joined UP apx asked if I would write a post on poison arrows for hunting.
I ended up doing a slightly broader post.
I'm also going to leave it here in DIY because as I gain more information I will post updates including methods for harvesting/cooking, storing and using.
Before I begin I just want to say that this information is purely theoretical and that you should always be aware of and abide by your local laws. Poisons will be harmful/fatal to you and others so DON'T DO IT. (I'm sure that this isn't necessary for any of you but one can never be too careful. )
Firstly you need to determine your intended use and source of your poison because not all can be used interchangeably, for example you wouldn't want to go hunting with nicotine sulphate because you'll most likely end up rendering your kill useless as it would be toxic to you in even tiny doses.
The most reliable source of information is usually to do research on the indigenous people of your area. Weighing up which to use always comes down to pros and cons. For example I prefer plants based poisons because once you're able to identify the plants it's quite simple to chop them up and boil them down with minimal risk to yourself whereas my sensei prefers using cobra venom because you require smaller doses and it remains effective for much longer once applied to arrows/darts but trying to attain their venom comes with great risk to yourself.
In toxicology the term LD50 (lethal dose 50%) is used. That means "what dosage is lethal 50% of the time".
When it comes to poison arrows you would most likely determine the LD50 of the selected toxin for the size game and double it (just to be sure). That poison is then distributed through the body before killing the the target so when you consume it's meat, even though you'll be ingesting some of the poison, it will be such a low concentration that it wouldn't be effective on you.(For example if you're using a protein based toxin with an LD50 of 2mg\kg you would require 100mg for a 50kg buck double that to 200mg. You then cut off 1kg of that meat to consume which theoretically contains 4mg of the toxin. With me being almost 100kg the concentration would only be 0.04mg\kg, far below the range of effect.) According to some sources this small dose can even help to develop a tolerance over time but even though I wouldn't test that theory it is not true for all poisons (cyanide and arsenic for example).
MOST poisons have many positive properties too (henbane for example) resulting in their use as medicines by many primitive men. If you think of it in relation to modern medicine, what can cure you can also kill you. It's all about the dosage.
Poisons can also be an effective form of security.
Homemade pepper spray with different plant additives can cause temporary blindness, hallucinations, respiratory and/or cardiac difficulties or even death.
Some poisons are very easily absorbed through the skin (pure nicotine for example) which makes them very useful for fortifications.
I plan for this to be a "living" thread which I will update/modify whenever I have time or fresh information. Once again, be safe and smart.