Countermoon

(Spell Compendium, page 53, DnD 3.5)

Abjuration

Level: ; Druid 2
Components: V, S, M
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Target: One lycanthrope
Duration: 12 hours
Saving Throw: Will negates (D)
Spell Resistance: Yes

Translucent red chains fly from your outstretched hand to wrap around the target before fading away.

This spell forces a lycanthrope back to its natural form and keeps it from changing form, preventing both voluntary shapechanging through the alternate form ability and involuntary shapechanging because of lycanthropy.

Material Component: A hair, scale, or other cast-off item from the type of creature.