All factor sheets

These molecules mimic or partially block the action of sex hormones; in men they are associated with lower testosterone and reduced sperm quality.

Unlike other cosmetics, perfume is applied directly to the skin repeatedly, which increases cumulative absorption.

Weak but measurable estrogenic activity in laboratory studies; human data on fertility remain contradictory.

Suspected interference with thyroid hormones, which help regulate the menstrual cycle and spermatogenesis.

Skin absorption is low but real; no solid study has measured an effect on human fertility.

A link to infertility circulates on social media.

A 2017 Hong Kong Consumer Council study (60 models tested) detected 1,4-dioxane in 60 to 70% of shampoos, and allergenic MIT/CMIT preservatives in about 20%.

ANSES and the DGCCRF (French consumer protection agency) (2018) tested several products and detected traces of dioxins, furans, glyphosate/AMPA, phthalates, and polycyclic aromatic hydrocarbons, but a…

Frequent use of scented products or internal douching disrupts the naturally protective vaginal microbiome and pH, which is associated with recurrent infections (bacterial vaginosis) and, in several s…

Each cosmetic product is assessed separately under regulation; actual exposure combines several products each containing a bit of different endocrine disruptors, whose combined effect is not measured…

Heat significantly increases the migration of plasticizers (bisphenols, phthalates) into food, and therefore real-life exposure.

Several families have hormonal activity; high consumption of heavily treated produce is associated with a lower sperm count.

Direct toxicity to reproductive cells and to the hormonal axis; lead is a recognized reproductive toxicant.

Emission of volatile compounds inhaled in enclosed spaces; hormonal effects are suspected for some synthetic musks.

NPE degrades into nonylphenol, classified as toxic to reproduction (category 2) and a suspected endocrine disruptor.

Some solvents such as glycol ethers are classified as toxic to reproduction; household exposure is lower but repeated.

PFAS (per- and polyfluoroalkyl substances) persist in the body and have been associated in some studies with a longer time to conception.

Fine particles sustain systemic inflammation and oxidative stress, associated with lower semen quality and longer times to conception.

Two effects are discussed: slight local warming and the effect of radiofrequencies.

At household exposure levels, studies have not shown an effect on human fertility, contrary to what is sometimes claimed.

Nitrates promote methemoglobinemia, a well-established effect especially in infants; a link with fertility remains emerging.

Chronic exposure to very low doses of active molecules; the effect on human fertility at these concentrations is poorly studied.

Chlorine reacts with organic matter in water and forms trihalomethanes; some studies link these to adverse pregnancy outcomes.

The regulatory limit (0.2 mg/L) reflects treatment quality rather than a demonstrated health risk; drinking water accounts for less than 5% of daily aluminum intake.

The general toxicity of arsenic is well established; its specific effect on human fertility is less documented.

Their presence in water is confirmed; the effect on human fertility is still poorly characterized.

Migration of microplastics (found in 93% of bottles tested, about 325 particles/L, more than tap water), antimony and acetaldehyde, increased by heat.

A high load of fast-acting sugars promotes insulin resistance, which is itself linked to ovulation disorders.

These additives are individually assessed at an acceptable dose; their combined and repeated consumption alongside other dietary sources (cocktail effect) remains little studied specifically for fertility.

A combination of excess sugars and low-quality fats, additives, and low nutritional density; associated with inflammation and oxidative stress that are unfavorable to gametes.

Each additive is assessed individually.

Nanoparticles (under 100 nm) penetrate the body more easily; animal studies have shown placental crossing, which prompted a precautionary ban — EFSA (European Food Safety Authority) cannot establish a safe daily dose.

Daily accumulation of hidden sugars, beyond drinks alone, promotes insulin resistance, itself linked to ovulation disorders and less favorable sperm parameters.

Nitrites and compounds produced during cooking promote oxidative stress; several studies link high consumption to lower sperm quality.

Bisphenol A binds to estrogen receptors and may disrupt oocyte maturation and sperm production.

Direct action on the hormonal axis of reproduction; the effect depends entirely on the molecule and the indication.

Voluntary and reversible blocking of ovulation.

Inhibition of prostaglandins, which are involved in ovulation and implantation; prolonged, high-dose use is associated with anovulatory cycles.

Signals of altered semen parameters and prolactin levels in small studies, not confirmed at larger scale.

Direct and sometimes lasting toxicity on oocytes and sperm-producing cells, depending on the doses received.

They cut off the pituitary signal that drives sperm production: spermatogenesis can stop, sometimes for several months.

Several independent, large-scale cohorts (2026 Swedish study on approximately 60,000 women, Swissmedic analysis, EARTH/Boston University studies, Sheba Medical Center) found no confirmed link with fem…

The copper IUD causes local inflammation of the endometrium and continuous release of copper ions; the hormonal IUD diffuses a progestin directly into the uterus.

Each medication is evaluated individually; the combined effect of several molecules taken together, on liver/kidney load and possible hormonal interactions, is little studied specifically for fertility.

Sperm production requires a temperature 2 to 4 °C below body temperature; repeated heating markedly reduces it.

Reduced ovarian reserve and accelerated ovarian aging in women; altered sperm count, motility, and DNA in men.

Disruption of the hormonal axis and direct, dose-dependent toxicity to gametes.

The endocannabinoid system is involved in sperm maturation and ovulation; regular use is associated with lower sperm concentration.

Persistently elevated cortisol dampens the pituitary command of the cycle and can delay or block ovulation.

The sleep-wake rhythm paces the secretion of reproductive hormones; its disruption affects the cycle and spermatogenesis.

Adipose tissue produces estrogens; in excess as in deficiency, it unbalances the cycle and lowers testosterone.

Promotes insulin resistance and low-grade inflammation; compounded in men by local scrotal heat.

Spray drift exposes nearby residents to pesticides via respiratory and skin routes, in addition to dietary exposure; several of the substances involved are endocrine disruptors or CMR (carcinogenic, m…