Monaghan and Dench will star opposite Jeremy Renner (The Hurt Locker) and Jennifer Garner (Juno) in the indie thriller.
Better Living Through Chemistry is David Posamentier and Geoff Moore’s first script, which the duo will also direct.
A straight-laced pharmacist’s (Renner) uneventful life spirals out of control when he starts an affair with a trophy wife (Garner) customer who takes him on a joyride involving sex, drugs and possibly murder.
Production is set to commence in August.
Dench will next be seen in Pirates of the Caribbean: On Stranger Tides, while Monaghan stars in Duncan Jones’ Source Code.