For years we have heard about the dangers of plastics. We switched plastic water bottles, replaced food containers, and became more aware of chemicals like BPA leaching from packaging into our food and drinks. But plastics are only part of the story. A far more difficult challenge hides in products we use directly on our bodies every day. Creams, shampoos, perfumes, sunscreens, deodorants, foundations, hair sprays, toothpastes, and many more. Products made from complex mixtures of chemicals that most people never stop to examine.

Modern beauty culture has transformed personal care into a massive global industry. Women and men are encouraged to build routines with dozens of products promising cleaner skin, shinier hair, a younger appearance, or a more attractive image. The problem is that many of these products contain chemicals capable of interfering with the body’s hormonal communication system. These substances are known as endocrine-disrupting chemicals.

This issue is an invitation to become chemically literate. To understand what these compounds are, why researchers are concerned about them, and how to make more informed decisions about the products we use daily.

The endocrine system is the body’s chemical communication network. It is formed by all the glands that produce hormones: the thyroid that controls metabolism and energy use, the adrenal glands that produce stress hormones such as cortisol and adrenaline, the pancreas that controls blood sugar through insulin, the ovaries and testes that produce estrogen and testosterone, and the pineal gland that regulates sleep through melatonin. All these hormones travel through the bloodstream and coordinate vital functions throughout the body such as reproduction, metabolism, growth, mood, sleep, energy balance, and brain development. Since hormones operate at extremely small concentrations, even subtle interference with this system can have physiological consequences.

Endocrine-disrupting chemicals (EDCs) are external chemicals capable of interfering with normal hormonal function.

Some EDCs partially resemble natural hormones and can activate hormone receptors, tricking the body by producing hormonal signals at the wrong time or intensity. Others can bind to hormone receptors without properly activating them, blocking the normal function of the hormone. Some endocrine disruptors can inhibit the biosynthesis of hormones by interfering with the enzymes and glands that produce them, resulting in abnormal hormone levels in the body. Others interfere with transport proteins that hormones bind to, preventing them from properly reaching their target tissues. Others can speed up or slow down the breakdown of hormones, making them remain too long or disappear too quickly from circulation. Some EDCs can even modify gene expression through epigenetic modifications.

Endocrine disruptors can have severe reproductive effects, causing infertility, pregnancy complications, developmental problems, and pregnancy loss. Extensive research has focused on these impacts, but research has also linked chronic exposure to some endocrine disruptors with thyroid dysfunction, metabolic disorders, obesity, insulin resistance, cardiovascular disease, neurodevelopmental problems, and certain hormone-sensitive cancers.

Many scientists are concerned about long-term low-dose exposure, and more research is still needed. The amounts found in personal care products might be low. However, these chemicals are often not encountered once, but repeatedly, every single day, through combinations of products used for years.

Personal care products can expose the body to endocrine-disrupting chemicals through several routes.

Skin absorption is the most obvious pathway. Creams, lotions, sunscreens, shampoos, and makeup are applied directly onto the skin, allowing certain compounds to penetrate the body. Lip products and oral care products can lead to accidental ingestion, while perfumes, sprays, powders, and aerosols can be inhaled.

The main categories of endocrine disruptors found in personal care products are:

Parabens are among the most common preservatives used in cosmetics and personal care products because they prevent microbial growth and extend shelf life.

They are commonly found in moisturizers, shampoos, conditioners, sunscreens, makeup, face washes, deodorants, and nail products. They are known to mimic estrogen and disrupt various hormonal systems.

Parabens are linked to irregular reproductive cycles, early menopause, Polyendocrine metabolic ovarian syndrome (PMOS), endometriosis, reduced sperm quality and count, thyroid dysfunction, and possible carcinogenic effects.

Several parabens have already faced restrictions in parts of the world. The European Union has banned isopropylparaben, isobutylparaben, phenylparaben, benzylparaben, and pentylparaben in cosmetic products due to safety concerns. Limits have also been placed on the concentration of propylparaben and butylparaben in cosmetics intended for children.

Phthalates are primarily used as plasticizers and solvents in perfumes, hair sprays, nail polish, scented lotions, and fragranced cosmetics to help scents last longer. One of the biggest challenges when identifying them is that they are often hidden behind the generic ingredient terms “fragrance” or “parfum.”

Phthalates are associated with early pubertal onset in girls, infertility, endometriosis, pregnancy loss, reduced testosterone production, metabolic disorders such as Type II diabetes, and increased risk of breast and ovarian cancer. The European Union has prohibited several phthalates, including DEHP, DBP, and BBP, in cosmetic products because of their reproductive toxicity.

These compounds are commonly found in sunscreens, foundations with SPF, lip balms with SPF, and moisturizers with SPF. Some UV filters are associated with altered sperm motility, reduced sperm count, disruptions in calcium signaling required for fertilization, and damage to structures involved in egg cell maturation that can lead to aneuploidy. They may also cause alterations in the prostate gland and possible liver, thyroid, and kidney dysfunction.

The European Commission recently reduced the maximum allowed concentration of homosalate in facial cosmetic products due to endocrine disruption concerns.

These antimicrobial compounds were widely used in antibacterial soaps, toothpastes, mouthwashes, and body washes. Research has linked them to hormonal disruption and reproductive toxicity in animal studies. Evidence also suggests reduced testosterone synthesis, poor semen quality, testicular torsion, altered reproductive cycles, and impaired implantation. Triclosan (TCS) is associated with menstrual irregularities, infertility, abnormalities in fetal development, and reduced levels of estradiol and progesterone.

Due to safety concerns, several countries restricted or removed triclosan from certain antibacterial consumer products.

Synthetic musks are fragrance chemicals commonly used in perfumes, deodorants, lotions, and scented products. These compounds are highly lipophilic, meaning they can accumulate in fatty tissues. Synthetic musks are linked to ovarian damage, early puberty, atrophy of seminiferous tubules, and a decline in sperm production and motility.

Here the same problem is repeated: many fragrance-related chemicals remain hidden behind the word “fragrance” on ingredient labels.

Per- and polyfluoroalkyl substances, known as PFAS, are a large group of extremely persistent chemicals, also known as “forever chemicals.” In cosmetics they are sometimes used to create products that are waterproof, long-lasting, smooth, and spreadable, such as waterproof mascaras, long-wear foundations, lipsticks, and eyeliners.

PFAS exposure has been linked to increased risk of gestational diabetes and preeclampsia, Type 2 Diabetes Mellitus (T2DM), thyroid dysfunction, metabolic disease, immune alterations, pregnancy complications, and reduced fertility. Several PFAS compounds are now being restricted internationally because of their persistence and bioaccumulative nature.

One of the biggest limitations of current safety research is that chemicals are usually studied one at a time. Real-life exposure is completely different. Most people do not use one product containing one chemical. They use shampoo, conditioner, perfume, moisturizer, sunscreen, deodorant, makeup, hair products, toothpaste, and cleaning products every day.

This creates a constant low-dose mixture of exposures that toxicology still does not fully understand.

A chemical may appear “safe” in isolation, while the long-term effects of combined exposure remain uncertain.

Modern life makes complete avoidance almost impossible. The objective is simply to reduce unnecessary exposure where we reasonably can.

Some practical ways to lower exposure include:

Scientific uncertainty still exists in many areas of endocrine disruption research. Human exposure is difficult to study because it occurs slowly, through mixtures of chemicals, over decades. But uncertainty should not be confused with absence of evidence. Becoming more aware of the chemicals we place on our bodies every day is not alarmism. It is simply a more conscious way of interacting with modern products.