Alchemy Labs allow you to create potions and poisons by combining ingredients that you find in the world.
All ingredients have four effects. You can learn the first effect of any ingredient by selecting it in your inventory and eating it. To learn the other effects, experiment with it.
For a full list of effects, see our Skyrim Alchemy Ingredients Guide
At an Alchemy Lab, you can combine any two or three ingredients and attempt to make a potion with them. If the ingredients share at least one effect, you succeed: You get the resulting potion or poison and learn all of the effects that matched. If none of their effects match, crafting fails and you lose the ingredients.
The resulting item is a potion if its strongest effect is beneficial, and a poison if its strongest effect is harmful. Potions may have weaker harmful effects, and poisons may have weaker beneficial effects. It all depends on the effects of the ingredients you used.
To use a poison, activate it in your inventory to apply it to your equipped weapon.
To use a potion, activate it in your inventory to drink it. If you drink two potions with the same effect, only the most powerful is applies, so wait for one potion to wear off before drinking the next.
As you discover ingredients with matching effects, the Alchemy Lab menu will remember the matches for future use. Continue to experiment to learn new effects and find better combinations.
Breton, Dark Elves, Khajiit, and Wood elves start with a +5 Alchemy skill bonus.
Alchemy perks include Alchemist that increases the strength of poisons and potions you create, Physician which increases the power of health and magicka potions, Benefactor which increases the magnitude of beneficial effects in potions you create, Experimenter which lets you reveal the first 2 effects of an ingredient by eating it, Snakeblood which grants you 50% resistance to all poisons, purity which removes unwanted effects from potions and poisons, Poisoner which increases the power of poisons you make, Concentrated Poison which increases the duration of the poison on your weapon, and Green Thumb that lets you gather two ingredients from plants.