Hormones

Hormones are a class of signalling molecules that exist in all multi-cell organisms and, in humans, include commonly-known examples like melatonin, testosterone, and cortisol.

Hormones are silent drivers of behaviour and personality, and their molecular fingerprints are on everything from attraction to appetite. Decades of biological and psychological research have found that certain hormones are associated with specific traits and behaviours, but in reality, the human endocrine system is so complex that the same chemical may behave radically differently from person to person.

Hormones affect people in different ways throughout their lives, and hormone levels can spike dramatically at physical or emotional transitions. New parents are slammed with a rush of hormones, for instance, as are rookie players on sports teams and tweens entering middle school.

Hormones serve a wide range of functions in the body and can trigger medical challenges when they fall out of balance.

How Hormones Affect the Body

Testosterone is what makes men so manly. Oxytocin is the “love hormone.” And cortisol is responsible for crazy amounts of stress, right?

Not exactly. Most of what the average person understands the role of hormones is a heavily simplified version of how they function in the human body.

In reality, testosterone is necessary for both males and females. Oxytocin can stimulate pleasant feelings and boost close bonds, but it has also been linked to feelings of social prejudice. And cortisol helps the body deal with stressful situations; it’s only when there’s too much of it present for too long that it starts to have negative effects.

Ultimately, hormones—even the same hormone—can serve a wide range of functions, from slowing growth to stimulating it, and from activating the immune system to inhibiting it. There is little in the human body that hormones don't play a role in; as a result, when hormone levels are thrown off balance, the effects can appear in a variety of ways.