All effects from potions/herbs etc are temporary. The only permanent change is that from the double-effect Throggi-holding-a-boulder vials (see below). Oh yeah - some temporary things last longer than others.

Healthy potion (short blue)	1 x Healing
Healthy potion (tall blue)	2 x Healing
Small vial (fancy blue)	3 x healing
Light green bottle	Restores lost str & dex, Increases str & dex
Dark green bottle	Restores lost strength points, increases strength
Smelly throggish brew	Cures poison
Throg-holding-a-boulder vial	Increases strength, 2nd one within a minute increases str to max, and also increases str permanently by one point
Bubbling blue potion (tan jar)	Increases strength, 2nd one increases dex
Decanter with a red brew	1 x healing, drunk
Red mushroom	Increases strength & agility
Green mushroom	Cures poison, weakness, and ???
Spotted mushroom	Removes magical effects?
Good smelling root	1 x healing
Really good smelling root	2 x healing
Musty smelling root	??? (no effect when eaten?)
Bad-smelling throg food	Lowers strength by 1?
A home-cooked meal	1 x healing
Some faerie cake	1 x healing
Fine faerie cake	2 x healing
Rowanberries	1 x healing, drunk
Gladiola	??? (no effect when eaten?)
Foxglove	??? (no effect when eaten?)
Wild thyme	??? (no effect when eaten?)
St John's Wort	Full cure & heal