Regeneration, Grinded Beef, Poison Eraser and Agility Potion can All be used from your Hotbar while riding a dino and it will effect the Dino itself while riding, once you dismount the Potion will Effect the Player instead, These Potions can ALSO be used in Dino or Player Inventory for the Same Effect.

New Tranqs: Alpha Arrows and Darts : Can be Used to Tranq up to Prime Tier dinos. Above Prime are immune to them.

Prime Arrows and Darts: Used to Tranq out anything that is Tranqable.

HP Injectors : Can ONLY be used from Hotbar on dino or player the Benefit of these is their reduced cooldown between uses 30secs vs 60 for the Potions.

Eternal and Alpha Kibble : NOT USED FOR TAMING! Used in Crafting Recipies and in some cases Fuel for certain things.

Crystal Sickle : can Harvest from Bushes like an Eternal Anky ie Extra Resources as well as higher amounts.

This Post may or may not be updated as time goes on but these are the most pressing items i've seen people getting Confused.