Sanford 1980 one on netflix: 1x6

Younger Than Springtime Am I

One of Fred’s customers, a shady salesman for a drug called methusadol, sells Fred a bottle of pills that he says will make him look younger and youthful again. Fred then takes these pill for $100 a bottle and he psychologically thinks that he is getting younger and that the pills are a breakthrough. When he takes it to Evelyn, she calls for a investigation on them and she tells him the bad news.