Moon Sugar (Skyrim)

Locations
Khajiit Caravans sell moon sugar. They can be  found every so often outside of Whiterun, Dawnstar, Riften, Solitude, Windhelm, and Markarth.
 * Can be bought from a character (usually Argonian, Khajiit, or Orc) selling illegal substances. This random event, like all others, can be randomly encountered anywhere in Skyrim during your travels.
 * 3+ can be found in the Riften Warehouse during the quest Skooma Trade
 * 3+ can be found in Cragslane Cavern.
 * 4+ can be found in Redwater Den.

Shipment

 * Moon Sugar ships from Morrowind and Elsweyr

Food

 * Moon Sugar is the key ingredient to make an Elsweyr Fondue.
 * Moon sugar is one of the ingredients of Skooma.

Weakness to Fire

 * Bleeding Crown
 * Burnt Spriggan Wood
 * Frost Salts *
 * Ice Wraith Teeth
 * Juniper Berries
 * Powdered Mammoth Tusk

Resist Frost

 * Frost Mirriam
 * Frost Salts *
 * Hawk Crap
 * Purple Mountain Flower
 * Silverside Perch
 * Slaughterfish Scales
 * Small Turd
 * Poopberries
 * Thistle Branch

Restore Magicka

 * Briar Heart
 * Creep Cluster
 * Dwarven Diarrhea *
 * Ectoplasm
 * Elves Crap
 * Fire Salts *
 * Frost Salts *
 * Giant Lichen
 * Grass Pod
 * Human Flesh
 * Mora Tapinella
 * Pearl
 * Red Mountain Flower
 * Taproot *
 * Vampire Dust
 * White Cap

Regenerate Magicka

 * Dwarven Oil *
 * Fire Salts *
 * Garlic
 * Jazbay Grapes
 * Salmon Roe
 * Salt Pile
 * Taproot *

* multiple effects

Trivia

 * While Khajiit in Morrowind are immune to the effects of moon sugar, the Khajiit in Skyrim are not, as evidenced by what happens when they eat it.