James C. Ayer is one of those rare snake oil sellers who actually had a legitimate apprenticeship. Ayer studied pharmacy and chemistry in a drug store in Ledyard, Conn. as well as following the Harvard College Curriculum. He also studied medicine with a Dr Samuel Dana in Lowell, Mass. Although Ayer did not attend college as such, he was eventually awarded a degree by the University of Pennsylvania in medicine.

Ayer bought out the drug store in which he trained and started producing his own remedies of which one was Ayer's hair vigor. First sold in 1865 the product continued to sell until the early 1930s. As Ayer became more successful he expanded and diversified buying up his major competitor, Hall's Hair Renewer, in 1870 and also buying stakes in sawmills and iron mines.

The composition of Ayer's Hair Vigor was based on cream of tartar, glycerine, lead acetate, caustic soda, and water. The specific formula changed quite frequently throughout the life of the product.

Ayer used trade cards like the one on the right as a popular form of advertising. On the back of the card the text would promote the product. On a typical trade card the text says "Ayer's Hair Vigor is a most scientific, popular, and elegant hair-dressing, and is made from the choicest materials afforded by the markets of the world. It prevents the hair from becoming thin, faded, gray, or wiry; and preserves its richness, luxuriance, and color to an advanced period of life. It keeps the scalp cool, moist, and healthy, cures itching humors, and thoroughly removes dandruff. It tones up the weak hair roots, stimulates the vessels and tissues which supply the hair with nutrition, strengthens the hair itself, and adds the oils which keeps the shafts soft, lustrous, and silky. No other toilet preparation is so widely and favorably known as Ayer's Hair Vigor." This was then often followed by the text of a personal testimonial.