The Twilight Zone (1985)

This episode is a cruel "fountain of youth" spin-off. A fortyish reporter is at risk of losing her anchor position on a network evening news broadcast to a younger reporter. She hears about a special type of bottled water from a friend of hers. She orders some at a relatively low cost. It works. Yet she finds she must drink it every day in order to retain her youth. When she orders another 5-gallon container. The price jumps up to $200. She talks to the water deliveryman. He refers he to her as "girlie". She remarks "girlie" is an old term and asks for his actual age. He says something along the lines of "I don't think you'd want to know". She is halfway done with the second bottle and is tearing apart her place looking for items to pawn when her husband shows up. They have no kids. She explains what has happened and decides to end her dilemma by balancing their situations.