Our next estrogenic is sunscreens! I don’t know of any sunscreen with a chemical UV filter in it
that doesn’t have some affinity for hormonal receptors in the human body. Some common ones are benzophenone-3 (BP-3), 3-benzylidene camphor (3-BC), 3-(4-methyl-benzylidene) camphor (4-MBC). But there are dozens of them. Watch out for the root “benz” or “phen” in the chemical name. Better yet, just don’t use a chemical based sunscreen. Chemical sunscreens are lipophilic, meaning they are attracted to fat and we all have a fatty layer
in our skin, so a lot of it absorbs right in. It doesn’t just stay on the surface.
Remember, the skin is an effective dosing route for hormones and drugs applied as creams. Yes, it acts as a barrier and a protection from exposures of lots of different kinds, but to substances with the right properties, your skin is like a wide open unguarded back door. And what goes in through the skin dumps right into the bloodstream without being metabolized at all by the liver like food and other things we swallow, which go to the liver first, then into circulation. It’s like getting these chemicals by injection. Yikes!
You may say well I don’t use sunscreen all that often, so this really isn’t an issue for me, but
remember it’s in cosmetics too. Make-up, skin creams, even some soaps! So daily application is a likelihood for a lot of people. Now chemical UV filters are required to be listed as an
ingredient in cosmetic products, but protecting human skin is not their only use. They also
protect other materials from the harmful effects of UV light, like plastics, carpet, and furniture.
Study on BP-3 found in urine of subjects with no documented exposure to it.
PMID: 16097788 Automated on-line column-switching HPLC-MS/MS method with peak
focusing for the determination of nine environmental phenols in urine
Chemical UV filters hit estrogen, androgen, and progesterone receptors, and effect thyroid
PMID: 22612478 Sunscreens: are they beneficial for health? An overview of endocrine
disrupting properties of UV-filters
PMID: 30597193 4-Methylbenzylidene-camphor inhibits proliferation and induces reactive
oxygen species-mediated apoptosis of human trophoblast cells.
PMID: 21783915 Low dose 4-MBC effect on neuroendocrine regulation of reproductive axis in
adult male rats.
Sunscreen additives BP-3, OMC, and 4-MBC are absorbed systemically.
PMID: 15191542 Systemic absorption of the sunscreens benzophenone-3, octyl-
methoxycinnamate, and 3-(4-methyl-benzylidene) camphor after whole-body topical application
and reproductive hormone levels in humans.
PMID: 31058986 Effect of Sunscreen Application Under Maximal Use Conditions on Plasma
Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial