The endocrine system: a quick explainer

By Emily Do

Many articles about chemicals used in beauty products talk about the negative effects of such chemicals on the endocrine system – that these substances can disrupt your hormones and lead to negative health impacts. 

But what even are hormones? What is the endocrine system? This article provides a quick explainer of the main components of the endocrine system, hormones, and how certain chemicals might cause harm.

What is the endocrine system?

The endocrine system is one of the two main communication systems of the body, the other being the nervous system. These two systems allow information to be transmitted across different parts of the body to coordinate the body’s response to its environment. 

The endocrine system deals in hormonal communication: Hormones are produced and released from different glands and are transported throughout the body to regulate different functions. Some of the main functions of hormones are to control growth and reproduction. 

The following table describes the different glands of the endocrine system, with some of the hormones each of them create.

GlandLocationHormones produced (not full list)
HypothalamusBrainDopamine, “pleasure” hormone
Pituitary glandBrain (below hypothalamus)

Growth hormone


 

Oxytocin, “love hormone” (also stimulates contractions in childbirth) 

Adrenal glandsAtop kidneysCortisol, helps control metabolism, protect from effects of stress
GonadsThese are the ovaries (for women) or testes (for men)

Estrogen, coordinates female development


 

Progesterone, causes changes in uterus in preparation for pregnancy/during pregnancy


 

Testosterone, coordinates male development (also present in women)

Thyroid glandIn front of windpipeThyroid hormone, helps stimulate heat generation, promote metabolic processes to produce energy
PancreasBehind stomachInsulin and glucagon, help regulate blood glucose

Endocrine disruptors

Certain chemicals in cosmetics can disrupt the endocrine system, making them “endocrine disruptors.” 

As seen in the above table, hormones play pivotal roles in development and reproduction, and these processes are often impaired by exposure to endocrine disruptors. To learn more about the specific health effects of endocrine disruptors (which include phthalates, parabens, and the “forever chemicals” known as PFAS), visit the article: What are all these chemicals? Parabens, phthalates, PFAS and more.