What are Gender Bending Chemicals?

We’ve all heard the striking phrase, ‘gender-bending chemicals’ but what exactly are they and should we be worried?

Why ‘Gender Bending’?

Gender bending chemicals are a vast and diverse group of chemicals which have been found to mimic, block, or alter the effects of growth and developmental hormones causing reproductive abnormalities in some animals.

Gender-benders most often seem to interfere with androgens, oestrogens, and thyroidal hormones and are also called endocrine disrupting chemicals or EDC’s.

Which Chemicals Are Endocrine Disrupters?

There are thousands of chemicals which may potentially interfere with the endocrine system and found in a vast range of everyday products.

The main chemical groups regarded as particularly problematic include:

  • Polychlorinated biphenyls (PCBs)
  • Pesticides
  • Flame Retardants
  • Phthalates (plasticising chemicals)
  • Organochlorines
  • Dioxins
  • Alkylphenols

Where Are These Chemicals Found?

Endocrine disrupting chemicals are found in all kinds of products including:

  • Cosmetics, shampoos, and toiletry products
  • Cleaning products
  • Pesticides, insecticides, herbicides
  • Plastics
  • Processed food
  • Pharmaceuticals
  • Chemicals for industrial use

How Do Endocrine Disrupters Work?

Our understanding of the way in which endocrine mimickers work is evolving all the time as more and more research work is carried out. Their effects are not as yet fully understood but it is known that they are able to change the gene expression, transportation, binding, production, and regulation of chemical signalers in the body.

With such widespread disruption to the intricate balance of the chemical make-up of the body, development, reproduction, metabolism, behaviour, and brain function can all be altered.

What Effects Can They Have?

Gender bending chemicals interfere with the correct functioning of the endocrine system. The result is an alteration in the way the body regulates hormones, triggering changes in body development.

Results studied in animals have observed ‘hermaphrodisation’, ‘feminisation’, ‘masculinisation’, and genital mutations in many species. Fish are particularly sensitive to chemical change, many of the most dramatic effects are reported in fish and fish-eating mammals and birds including the following:

  • Female fish which have developed male sex organs
  • ‘Hermaphrodite’ polar bears with disfigured penises
  • Male Alligators with abnormally small penises
  • Abnormally large amount of deformed chicks hatched by sea-birds
  • Intersex frogs – i.e. have one egg, one ovary, or eggs in their testes.

Human Manifestations Of Gender Bending Chemicals

Although the long-term effects of endocrine disrupting chemicals on the human body are unclear, there is enough evidence to suggest that high exposure in the womb for male babies may well affect their ‘maleness’. Some studies suggest that a slight feminisation could occur and penises could be less well developed.

These so-called gender bending chemicals are also being linked to a falling sperm count in males, a higher rate in fertility problems, undescended testes, and a ‘de-masculinisation’ in behaviour.

In women problems could be higher incidences of polycystic ovarian syndrome (POS), endometriosis, abnormal uterine development, and pelvic inflammation.


Links to the incidence of cancers in hormonally-sensitive areas have also been made to endocrine disrupters. The development of testicular, prostrate, thyroid, endometrial, and breast cancers could all possibly be accelerated by high or long-term exposure to such chemicals.

There is much more research to do on the effects of gender bending chemicals but if you are worried, advice would be to limit your exposure particularly if pregnant.