[3DMaster]

I don't want to kill the Troll, after all. I had the troll tongue from his wife's head, but apparently it got used up in a bloody formula (seriously, quest important ingredients like this, at the very least should be asked a confirmation if you want to use them up in formula, if not ever end up in a formula automatically to begin with!), and I can't buy the one that Cedric has for sale, because he just died.

Somebody, please, please, please tell me there's another way to get a troll tongue in Act 1 instead of killing the Troll; I want to finish melitele's heart and I need the bloody troll tongue for that.

[riselka]

You can buy another one from Cedric

[3DMaster]

Like I said, it's too late for that. Cedric is dead.

[Guy N'wah]

If that is so, then the only remaining solution is, sadly, to kill the poor troll. Is it worth it? Nothing depends on this quest, and the amulet is not that useful.

Yes, this game has a bad habit of using dual-use ingredients for alchemy. Known bug (or at least a nasty misfeature), hasn't been fixed.

[dragonbird]

If you're on PC, there are a couple of mods at The Nexus for adding all items to either the Mysterious Merchant shop, or to Innkeepers. It may be worth trying one of them.

If the mod hasn't been updated to EE, it will still be safe to use just to get the troll tongue, but uninstall it again afterwards. If it's already at EE, should be OK to leave in place.

I haven't tried it myself, but this one should be OK from the description.
http://witcher.nexusmods.com/mods/275

And keep an eye open for any update to Panel Tweaks over at The Nexus. It includes a feature to stop the game from using quest items in recipes. I'm really missing that mod right now - it's been hidden by the modder, and I'm hoping it's because he's updating it for EE.

[3DMaster]

I'm missing that mod as well. Used a mod to get my tongue.

[spacehamsterZH]

Always, always, always check what ingredients are used for potions. I learned that the hard way too. Harpy egg? Sure I have a harpy egg. I've got like a dozen. Wait, where are they?

[kingkiller1001]

Does some ingredients make potions more potent?
I noticed you can change ingredients...

[dragonbird]

No, it's just alternatives. The game AI doesn't always make the best decision - I think it just tries to free-up inventory slots or something, which isn't the best way of deciding.