Question: witcher 3 do decoctions stack?
Answer: While a decoction is working, the effects of other potions will stack more quickly. ... It's important to note that this won't activate the Killing Spree or Frenzy abilities, as they are specific to POTION toxicity. Having 2 or even 3 decoctions active at once is possible, and Tissue Transmutation give a bonus for each.