Many a paycheck has been spent on lipstick and lip plumpers—and with good reason!

A woman’s lips are a visible expression of her youth and fertility—the fuller your lips, the higher your estrogen hormones. (Explains why men aren’t out there seeking lip injections, eh?)

Luckily, even if you’re on the thin side, it’s a look that can easily be faked with a few clever makeup tricks. Regardless of your lip shape, adding any amount of color to your lips is a surefire way to send out beauty signals to the world.

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That lively, red color of your lips is an important signal of health. For one, pale lips can be a sign that you have anemia (i.e. low red blood cell count) and a blue-ish tint reflects a lack of blood oxygen.

Women naturally have more contrast than men between their features and their skin, so it’s no wonder that women since the beginning of human history have been darkening their lips in an effort to emphasis their femininity.

Women have been applying color to their lips since 5000 B.C., and today almost 1,500 tubes of red lipstick are sold every minute in the United States. Clearly something is working!

As Betsey Johnson once said: “If I were dying, I would be in the hospital wearing lipstick.” Amen!