Do they use poisons and health potions etc?

I was fighting this one guy and I swear his health jumped up...

Do mages use healing spells also?

Pretty much been known by anyone who's played the game for longer than 10 minutes since it was released.

I know it's certainly been that way since Oblivion, which was what annoyed me about fighting mages, given how some types seemed to have an abundant supply.

Well I can`t see the health bar, but I`ve seen that weird effect on mages when I think they`ve used heal potions. Happens quite a few times on Master.

Just makes me hack at them even faster!

you can't see your enemy's health?

Enemy NPC's only seem to heal with magic. Followers don't use jack. Another wasted opportunity on Bethesda's part.

Companions don't seem to drink the potions but i am sure NPC's do.

I made some custom enemies that I've added to a fort i am building, each had a restore health potion and when fighting them they most certainly do heal. Although oddly, i have noticed that sometimes they heal (not via spell) and yet when i kill them the potion is still in the inventory.

I've given both Lydia and Argis health potions and I saw the swirl that mean's it was used, on them both. During battle. Noticed it not to long ago and I've been playing since release.

Enemies I have seen use potions can't say about followers I have traveled alone so far.

I gave lydia some minor health potions, and Ive seen her glow after using them in battle.

NPCs do not expend items after using them, for some dumb reason.