Creams and lotions or risky potions? The dangers of endocrine-disrupting chemicals

INTRODUCTION

Endocrine-Disrupting Chemicals (EDCs) or endocrine disruptors are chemical agents that may mimic or interfere with the body’s endocrine system. EDCs are present in many everyday products. Cosmetics and personal care products often contain parabens, phthalates, and synthetic fragrances that may act as EDCs. Moisturizers and lotions can have chemicals that interfere with hormone function. Food packaging materials, such as plastic containers and can linings, may leach chemicals like bisphenol A (BPA) into food. Household detergents frequently contain surfactants and preservatives with endocrine-disrupting properties. Plastic bottles and containers used for storing food and beverages commonly include BPA and phthalates. Even children’s toys may contain phthalates, which have been shown to disrupt hormonal development.¹

Xenoestrogens are a type of EDC that mimics estrogen and can interfere with endocrine processes. Xenoestrogens can be found in everyday items such as phthalates, polychlorinated biphenyls, and parabens. Exposure to xenoestrogens can lead to many health issues, including breast, prostate, and uterus cancer, as well as reproductive and immune system dysfunction.

The endocrine system regulates the body’s development, growth, reproduction, metabolism, immunity, and behavior through the production of hormones. EDCs interfere with this precisely coordinated system, resulting in potentially life-long health effects that can even have consequences for the next generation by genomic involvement or epigenetic mechanisms.^2,3

These chemicals are also absorbed through dermal exposure; therefore, knowledge of these is especially relevant in dermatoses with impaired skin barriers such as atopic dermatitis, acne, or rosacea⁴ in which systemic absorption of ingredients in topical creams and moisturizers is likely to be enhanced.

WHAT ARE ENDOCRINE DISRUPTORS?

An endocrine disruptor is an exogenous chemical or mixture of chemicals that can interfere with any aspect of hormone action. Examples include phthalates, parabens, triclosan, BPA, and dioxins, to name a few.¹

Of the hundreds of known EDCs, a subset is present in personal care products like moisturizers, making them relevant to dermatologists.⁵ Since the skin is the largest organ of the body, systemic absorption through it is significant, especially when the skin is inflamed. Therefore, we are focusing on topical products containing EDCs, such as moisturizers, as they pose a greater risk of absorption and potential hormonal disruption.

There is no safe dose of EDCs and they act in very small concentrations. Invariably individuals are usually not exposed to a single type of EDC but to a mixture of EDCs.²

MECHANISM OF ACTION OF EDCS

EDCs mainly produce adverse effects by disrupting the functioning of the endocrine system through the following mechanisms [Figure 1]:^6,7

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Figure 1:

Mechanism of disruption of endocrine system by endocrine-disrupting chemicals. EDC: Endocrine-disrupting chemicals.

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1. Binding to a hormone receptor leading to activation or inhibition of its signaling pathway

2. Interactions with components of hormone signaling pathway downstream of a receptor

3. Stimulation or Inhibition of an endogenous hormone biosynthesis

4. Binding to circulating hormone-binding protein

5. Stimulation or inhibition of hormone-binding protein synthesis or degradation

6. Stimulation or inhibition of hormone receptor expression.

MAIN CHARACTERISTICS OF EXPOSURE TO EDC

The main characteristics of exposure to EDCs are as follows⁸–

• No Safe Dose: EDCs can have effects even at very low concentrations, and because they interact with endogenous hormones, it is challenging to define a threshold level below which they do not cause harm.

• Vulnerable Periods: Exposure during critical stages of development – such as pregnancy, lactation, and puberty – can lead to long-lasting damage that affects the individuals throughout their life and may be passed onto future generations.

• Non-Linear Dose-Response: The relationship between the dose of EDCs and the resulting adverse effects is not linear, meaning the response does not necessarily increase proportionally with the dose.

• Mixture Exposure: Individuals are typically exposed to a combination of EDCs rather than a single chemical. The interactions among these chemicals – whether synergistic, additive, or antagonistic – make it difficult to predict their overall effects, often referred to as the “cocktail effect.”

• Transgenerational Effects: The effects of EDC exposure can extend beyond the exposed individual, impacting future generations through genomic or epigenetic mechanisms. Establishing a clear causal link is complicated by the long latency periods between exposure and observable effects.

EFFECTS OF EDCS ON VARIOUS BODY ORGANS

EDCs disrupt the neurodevelopmental system and neuroendocrine system

Animal studies have demonstrated that developmental exposures to EDCs can alter the structure and function of the brain’s neuroendocrine system.⁶

The central neuroendocrine systems of the body serve as an interface between the brain and the endocrine systems in the rest of the body.¹² This is essentially regulated by the hypothalamic-pituitary-adrenal axis and the hypothalamic-pituitary-gonadal axis.⁶

EDCs exert neuroendocrine actions by acting on nuclear hormone receptors that are expressed in hypothalamic or pituitary cells, thereby altering feedback effects.

EDCs also cause impairment of cognition, learning, and memory possibly by causing alteration in the levels of neuromodulators such as dopamine, norepinephrine, serotonin, and glutamate.¹¹ In humans, epidemiological data support associations between higher exposures to EDCs with decreased Intelligence quotient (IQ), neurodevelopmental problems, and other neurocognitive outcomes.⁶ Summary of systemic effects of endocrine disrupting chemicals have been summarized in Table 1 and Figure 2.

Table 1: Summary of systemic effects of endocrine-disrupting chemicals.

System	Description	Effects
Female reproductive system	EDCs such as parabens, phthalates, and triclosan alter estrogen levels and inhibit testosterone production by Leydig cells.	Impaired folliculogenesis Irregular cycles Delayed fertility/infertility Polycystic ovarian syndrome Precocious/delayed puberty
Male reproductive system	Prenatal exposure to EDCs disrupts Leydig cell development, reducing testosterone production.	Cryptorchidism Hypospadias Poor semen quality Testicular abnormalities Risk of testicular cancer
Cancer	EDCs, especially parabens, have estrogenic effects and stimulate insulin-like growth factor-1 and epidermal growth factor, leading to carcinogenesis in hormone-sensitive tissues.	Breast, ovarian, and cervical cancer
Thyroid gland	EDCs affect thyroid function through central regulation, hormone synthesis, and metabolism pathways.	Hypothyroidism Disrupted Thyroxine (T3/T4) synthesis Thyroid carcinoma Developmental issues in newborns
Diabetogenic and obesogenic effects	EDCs such as phthalates and parabens disrupt adipogenesis and glucose metabolism.	Weight gain Increased body mass index/waist circumference Impaired glucose metabolism Diabetes and metabolic disorders
Neurodevelopmental and neuroendocrine systems	EDC exposure alters brain structure, neuroendocrine function, and neurotransmitter levels.	Impaired cognition, learning, and memory Neurodevelopmental problems Lower IQ Neurocognitive issues

EDCs: Endocrine-disrupting chemicals

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Figure 2:

List of organs affected by endocrine-disrupting chemicals.

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EFFECT OF EDCS ADDED IN MOISTURIZERS ON HUMAN HEALTH

There are multiple EDCs commonly present in skincare products, including moisturizers available across the globe. The most common ones are described as follows:

EDCS IN SPECIAL GROUPS

1. Children-Endocrine disruptors may have different effects in developing fetus or in infantses as compared to adults. It is important to understand that infancy, childhood, and puberty are critical periods of development during which developing systems are “particularly sensitive to hormonal or other disruptions” for many reasons:

   1. Organ development continues through this period

   2. Infants’ immune systems is immature; hence, they are incapable of detoxifying and eliminating toxic chemicals

   3. Infants and young children have thinner skin than adults; therefore, chemicals are more easily absorbed.²⁵

2. Pregnancy-Exposure to EDCs during pregnancy has been associated with the onset of severe gestational conditions such as preeclampsia, fetal growth restriction and gestational diabetes in the mother, and reproductive tract anomalies in the fetus.^26,27

   High levels of estrogen exposure in utero have been linked with several male reproductive tract abnormalities, including cryptorchidism, hypospadias, impaired spermatogenesis, and testicular tumors. Moreover, many research studies strongly indicate that the placenta is not such an effective barrier against EDCs and that pregnant women’s exposure was associated with EDCs’ entrance in the fetal circulation. The developing fetus might be more sensitive to EDCs than the adult. Thus, EDCs could negatively impact fetal and placental health by interfering with the embryonic developing epigenome, thus establishing disease paths into adulthood.²⁶

3. Lactation-Exposure to EDCs in postnatal life through breast milk may interfere with germ cell development.²⁷

PURPOSE AND IMPORTANCE OF PRESERVATION

Cosmetic products, including moisturizers, makeup, shampoos, and serums, often contain water-based ingredients that create an ideal environment for microbial growth. Without proper preservation, these products can degrade, leading to changes in appearance, texture, and safety. Preservatives play a key role in maintaining the stability, effectiveness, and longevity of cosmetic formulations. Parabens offer broad-spectrum protection against bacteria and molds with excellent stability, while phenoxyethanol is a cost-effective option effective across a wide pH range. Benzyl alcohol is skin-friendly and compatible with various ingredients, targeting bacteria and yeasts. Formaldehyde releasers provide long-lasting preservation, making them suitable for natural formulations. Sorbic acid and benzoic acid are commonly used to combat molds, yeasts, and certain bacteria, often in combination with other preservatives. Ethylhexylglycerin enhances antimicrobial activity while also conditioning the skin, whereas caprylyl glycol offers hydration along with antimicrobial benefits. Sodium benzoate and potassium sorbate are widely used in water-based formulations to extend shelf life. Natural extracts and botanical blends, such as rosemary or grapefruit seed extracts, serve as eco-friendly alternatives, often combined with other preservatives for enhanced efficacy. Selecting the appropriate preservative depends on formulation type, pH compatibility, and product longevity requirements.

ROLE OF FORMULATION FACTORS IN EDC ABSORPTION

The absorption of EDCs through the skin is significantly influenced by various formulation factors in cosmetic and personal care products. These factors determine the extent to which EDCs penetrate the skin barrier and enter systemic circulation.

• Vehicle Composition: The type of solvent or base used in a formulation affects the solubility and penetration of EDCs. Lipophilic solvents (e.g., oils and alcohols) can enhance absorption by disrupting the skin barrier, whereas hydrophilic bases may limit penetration.²⁸

• Emulsifiers and Surfactants: These compounds, commonly found in creams and lotions, can alter skin permeability by interacting with lipids in the stratum corneum, potentially facilitating EDC absorption.²⁸

• Molecular Size and Lipophilicity: EDCs with low-molecular-weight and high lipophilicity tend to penetrate the skin more easily, particularly when incorporated into formulations that promote their solubility.^29,30

• pH of the Formulation: The skin has a slightly acidic pH (4.5–5.5), and formulations with extreme pH values may compromise the integrity of the skin barrier, enhancing the penetration of EDCs.^29,30

• Occlusion and Hydration: Occlusive formulations, such as ointments or thick creams, increase skin hydration and may enhance the absorption of EDCs by disrupting the natural barrier function.^29,30

THE IMPACT OF CUMULATIVE EXPOSURE TO EDCS: A PERSISTENT HEALTH RISK

Many EDCs are persistent in the environment and bioaccumulate in living organisms, meaning prolonged exposure could lead to higher internal concentrations over time. Even after their prohibition in some regions, these chemicals continue to affect populations, highlighting the ongoing risk of long-term exposure. In addition, EDCs can cross the placenta and be transmitted through breast milk, impacting fetal and neonatal development, with a long latency period between exposure and disease manifestation. Their mechanisms of action, including interference with hormone synthesis, receptor binding, metabolism, and epigenetic modifications, suggest that cumulative exposure may lead to lasting effects. Chronic exposure has been correlated with metabolic syndrome, obesity, and hormone-related cancers such as breast and prostate cancer, conditions that typically develop over time. While a precise dose-effect relationship is unclear, the persistence, bioaccumulation, and long-latency effects of EDCs strongly imply that prolonged and repeated exposure increases the risk of adverse health outcomes.³¹

LABELING STANDARDS IN INDIA

As per Chapter VI of the Cosmetics Rules, 2020, Section 34(7) states that all cosmetics must list ingredients present in a concentration of more than 1% in descending order of weight or volume, followed by those in a concentration of 1% or less in any order. The list must be preceded by the word “INGREDIENTS.” However, this requirement does not apply to packages smaller than 60 mL for liquids and 30 g for solids or semi-solids.

In addition, Section 34(8) mandates compliance with labeling requirements as per the Bureau of Indian Standards (BIS) for cosmetics listed in the Ninth Schedule.

Thus, while most cosmetic products are required to display a full ingredient list, small-sized packs are exempt, and compliance with BIS standards is necessary.

PARABEN-FREE AND FRAGRANCE-FREE LABELS

Paraben- and fragrance-free labeling has gained popularity among consumers seeking safer skincare options; however, the absence of these ingredients does not necessarily ensure absolute safety. Many alternative preservatives, such as methylisothiazolinone, have been linked to increased cases of allergic contact dermatitis, raising concerns about their widespread use.³² Similarly, “fragrance-free” does not always mean the complete absence of scent-related compounds, as some products may contain botanical extracts or masking agents that can still cause sensitization.³³ Furthermore, certain preservative alternatives used in cosmetics, especially in spray formulations, may pose potential inhalation risks.³⁴ Therefore, while such labels may appeal to consumers, an evidence-based approach to ingredient selection is crucial. Our manuscript emphasizes the importance of evaluating product safety based on scientific data rather than marketing claims, ensuring that dermatologists and consumers are well-informed about potential risks.

CONCLUSION

EDCs are environmental pollutants that interfere with the hormonal systems of humans and wildlife. These chemicals, found in pesticides, plastics, personal care products, and industrial waste, enter the environment through agricultural runoff, improper waste disposal, and industrial emissions. EDCs such as BPA, phthalates, and parabens can mimic or block natural hormones, leading to developmental, reproductive, neurological, and immune system disorders. They persist in soil, air, and water, accumulating in the food chain and posing long-term risks to ecosystems and public health. Addressing EDC pollution requires stricter regulations, sustainable practices, and public awareness. At present, much of the available data pertaining to the side effects of EDCs exists in animal studies. Generating human data on EDC exposure requires large-scale epidemiological studies and biomonitoring programs that assess exposure levels, biomarkers, and health outcomes over time. Longitudinal studies tracking individuals with varying levels of exposure can help determine cumulative effects and latency periods. Future research should focus on standardized exposure assessment methods, integrating real-world exposure data with clinical findings to establish clearer causal relationships in dermatology.

While it may not be possible to eliminate these toxic chemicals from our day-to-day lives, it is prudent that we minimize their exposure. This holds even more importance for individuals in special age groups and also for patients with impaired barrier function, for instance, dermatitis, rosacea, or acne, where chances of dermal exposure are higher. Therefore, it should be ensured that these patients are prescribed moisturizers that are devoid of harmful EDCs such as parabens, fragrances, and phthalates.

With growing awareness and regulatory scrutiny surrounding EDCs, integrating their study into the medical curriculum is essential for equipping healthcare professionals with the knowledge needed to assess and mitigate related health risks. Given the potential links between EDC exposure and various systemic and dermatological conditions, medical education should include foundational topics such as sources of exposure, mechanisms of endocrine disruption, bioaccumulation, and long-term health effects.