I didn't realise until just recently how much fun it is sneaking around at night poisoning people (buh-bye Nazeem, the cloud district will miss you, [censored]), and I was wondering what the most effective poison recipe(s) were for quick kills and dealing the most damage, and if it can even kill guards with one dose that'd be pretty cool too.

Any other cool recipes would be nice to know too, I took a look via google but got a lot of conflicting info.

Oh, knowing good places to find required ingredients would be nice too, hehe.

Thanks in advance.

This should probably be in the spoilers/hints forum. I'm not sure if the mods are still policing it this long after launch, but this thread may end up locked.

We are here. We are always here.

Paralyis and Damage Health.
Canis Root and Fungal Swamp pod(paralysis) for Example, but power varies between the two ingredients, say Poison Bloom is a powerful poison, and Nirnroot, a weak poison is combined, It will only be as powerful as the most powerful Ingredient, and sometimes, you can make a potion that Makes your target Invisible, by poisoning them, It can make it extremely powerful when you dont have to worry about an Invisible guy heading down a river.

You can find ALOT of ingedients at the Arch Mage's Quarters, then if you have Hearthfire, you can start a Poison farm, dont use them on Draugr or DBH members.

Ok, now that it's been moved to the right forum.

First suggestion: UESP.net is a great resource - it is a very extensive and accurate wiki of all the Elder Scrolls games.

Second: I'm pretty sure the order of effectiveness for poisons is "poison" < "lingering poison" < "ravage X". But, the rarity of the ingredients goes up with each step. So, practically speaking, you'll probably just want to use "lingering poison" most of the time as it's more common than "ravage X". But, according to UESP, spadetail and perch both have Ravage Health, so if you go fishing, you might be able to catch enough to make a good supply of Ravage Health poisons.

Of course, if your skill is low, and you lack perks, the poison probably won't be much good anyhow, but still. Master level poisons with perks, plus fortify alchemy enchantments will allow you to make devastating poisons which will do something like 1000 or 1200 damage (one of the alchemy perks doubles the durations of poisons; I think the 'base' maximum is around 600 damage, but if the poison lasts twice as long, that'll go to 1200). However, if the target doesn't die first, it might take up to 20 seconds for the poison to fully kill them (although, on adept difficulty, I don't think there's any humans with that much health).