P&G Needs a Workout, Not Vitamins

Consumer products maker should focus on fixing its core business to resume growth

European dietary supplements won’t cure what ails Procter & Gamble.

P&G said Thursday it has agreed to acquire the consumer health business of Germany’s Merck KGaA for $4.2 billion, whose portfolio features a nasal decongestant and various specialty dietary supplements.

The deal news came as the Cincinnati consumer products giant...