Skin and haircare products and your thyroid

The majority of people around the globe regularly use at least one cosmetic product, including soaps, bath and shower products, hair shampoos, toothpaste, deodorants or make-up products.

All the ingredients used in cosmetic products meet certain regulatory requirements, and many of the ingredients are allowed to be used within lower concentration limits while they might or will become harmful at higher concentrations (1).

Three major aspects of skin and hair-care products that should be considered are (2–6):

1. Acute allergic reactions — usually caused by contact allergens (see the allergen list below)
2. Possible long-term effects — usually caused by ingredients that are disrupting the hormonal balance in the body (see the endocrine disruptor list below)
3. Additive and cocktail effects — the same ingredient might be present in several products you use, or different ingredients might cause similar reactions (see the endocrine disruptor list below)

Allergic reactions

In recent years, allergic reactions to cosmetics products have been increasingly reported. Any of the product ingredients may cause an allergic reaction, but some — such as fragrances and preservatives — cause it more frequently than others (7, 8).

List of potential contact allergens (9–27):

• Wool alcohols, fatty alcohols (e.g., cetyl alcohol), and propylene glycol
• Dicaprylyl maleate, isononyl isononanoate and trioley phosphate, and the humectants butylene glycol, and pentylene glycol
• Ethylhexylglycerin, and methoxy PEG-17 and PEG-22/dodecyl glycol copolymers
• Plant extracts, such as essential oils or extracts with antibacterial or antifungal properties, for example tea tree oil
• Oatmeal, hydrolysed wheat, or soybean extracts
• Paraphenylenediamine (PPD) in permanent hair dyes
• Benzophenones and octocrylene in sunscreen creams
• Persulfates in hair bleaches
• Cocamidopropyl betaine, methylchloroisothiazolinone, formaldehyde-releasing preservatives, propylene glycol, Vitamin E (tocopherol), parabens and benzophenones in shampoos
• Formaldehyde formulations and the glutaraldehyde in hair straightening products

Long-term effects through hormonal/endocrine disruptors

Endocrine disruptors are chemicals that can interfere with hormonal (endocrine) systems.

Endocrine disruptors are present in many of the daily used cosmetics, and exposure to them can be harmful for the thyroid (28–30). The concentrations in which endocrine disruptors are used in cosmetics are considered safe, but it is unclear how they build up in the body, and what long-term risks they are exposing people to (31–34).

Common and known endocrine disruptors (35–52):

• Parabens — used as antimicrobial preservatives and are very common in the environment. The EU and ASEAN banned five parabens (isopropylparaben, isobutylparaben, phenylparaben benzylparaben; and pentylparaben. Other parabens still commonly employed in cosmetics because they were judged as safe include: propyl-paraben, methyl-paraben, ethyl-paraben and butyl-paraben.
• Other preservatives — (I) Benzoic acid; (II) Formaldehyde and paraformaldehyde – allowed in cosmetic products up to 0.2% when used as preservative and up to 5% if used in nail hardeners according to the Cosmetic EU regulation 1223/09; (III) Climbazole has also been discussed in regard to potential endocrine disruption; (IV) o-Phenylphenol (OPP), sodium-OPP and potassium-OPP — data regarding their safety has been ruled too limited to predict or exclude health risks.
• Fragrances — such as musk xylene or musk ketone have been listed as a substance of high concern by the EPA as they are capable of high levels of bioaccumulation. The European Union has established a maximum authorized concentrations for musks ketone and xylene (1.4% and 1.0% respectively) and banned them in oral products. Other potential endocrine disruptors active in fragrances include diphenyl ether, several terpenes and essences and benzyl acetate.
• Cyclic Siloxanes — Siloxane D5 was classified as a substance of very high concern by the European Union. Siloxane D5 has been scheduled for limitation to 0.1% in wash-off cosmetics starting in 2020.
• Alkyphenols — classified as xenoestrogens — the European Union has restricted their use, due to toxicity, persistence and possible bioaccumulation.
• UV Filters — including Ethylhexyl dimethyl PABA, or Padimate O, Octinoxate and benzophenones — most show effect on estrogen activity
• Phytosterols — commonly found in soy
• Skin whitening ingredients — some interfere with the iodine uptake by the thyroid cells
• Alcohols — both ethylene glycol and diethylene glycol were related to antiandrogenic and antiestrogenic activities
• Phthalates — found in nail polish (dibutyl phthalate), hairspray (dimethyl phthalate), and perfumes and lotions (diethyl phthalate). Phthalates have been connected to altering the HPA-pituitary-thyroid axis
• Bisphenol A — have been connected to altering the HPA-pituitary-thyroid axis
• Petrolatum — paraffinum liquidum/petrolatum/paraffin/vaseline/mineral oil — with hydrocarbons derived from petrol are the most present contaminants in the human body

You should take in consideration the length of the exposure: leave-on and make- up products are of more concern, as they stay longer on the skin.

Governing bodies in charge of cosmetic product safety (53):

• In the EU: European Cosmetic Toiletry and Perfumery Association (Colipa)
• In the USA and Canada: FDA and NHP

Most of the skin complaints are still reported to the GPs, as they are considered the best and easiest first step towards visiting dermatology specialists (54). If you go to your doctor with a skin adverse reaction, you can ask them how to proceed with filing an undesired effect report to the responsible authority.

What can you do to make sure your products are safe for your thyroid:

1. Get informed — check ingredient lists, check Colipa — The European Cosmetic and Perfumery Association or FDA and NHP. The current EU regulatory framework provides an extensive list of banned ingredients or substances as well as limited ones, but it does not contain a positive list of allowed ingredients. The Inventory of Cosmetic Ingredients filed by the European Commission can be found here.
2. Report your side effects — EU’s national contact points for reporting serious undesirable effects: https://ec.europa.eu/docsroom/documents/45444. As of 2013, the new European regulation requires that serious undesirable effects reported to the competent authority should be transmitted to the competent authorities of the other Member States and to the person responsible for the cosmetic product (55).
3. Note your immediate side effects to any new cosmetics product you are using and talk to your health care provider about it.

How we write: our information is based on the results of peer reviewed studies using the National Library of Medicine platform. It is written by scientists and reviewed by external experts. If you believe we might have overseen crucial scientific information, please contact us at hello@boostthyroid.com

Disclaimer: This information is not intended to mitigate, prevent, treat, cure or diagnose any disease or condition. If you want to change your treatment, lifestyle, your diet, include supplements in your diet or have concerns about your health, please consult your doctor before trying new approaches.

References:

1. European Parliament. Regulation (EC) no. 1223/2009 of the European Parliament and of the council of 30 November 2009 on cosmetic products, 2009

2. Patisaul HB, et al. Long-term effects of environmental endocrine disruptors on reproductive physiology and behavior, 2009

3. Park JD, et al. Human exposure and health effects of inorganic and elemental mercury, 2012

4. Duarte I, et al. Frequency of dermatoses associated with cosmetics. Contact Dermatitis, 2007

5. Kartono F, et al. Irritants in combination with a synergistic or additive effect on the skin response: an overview of tandem irritation studies, 2006

6. Uter W, et al. Coupled exposure to ingredients of cosmetic products: I. Fragrances, 2013

7. Goossens A. Contact-allergic reactions to cosmetics, 2011

8. Patel S. Fragrance compounds: The wolves in sheep’s clothings, 2017

9. Lotery H, et al. Dicaprylyl maleate — an emerging cosmetic allergen. Contact Dermatitis, 2007

10. Goossens A, et al. New cosmetic allergens: isononyl isononanoate and trioleyl phosphate, 2008

11. Gallo R, et al. Allergic contact dermatitis from pentylene glycol in an emollient cream, with possible co-sensitization to resveratrol, 2003

12. Linsen G, et al. Allergic contact dermatitis from ethylhexylglycerin. Contact Dermatitis, 2002

13. Le Coz CJ, et al. Allergic contact dermatitis from methoxy PEG-17/dodecyl glycol copolymer (Elfacos OW 100), 2001

14. Goossens A, et al. An epidemic of allergic contact dermatitis due to epilating products, 2002

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16. Nardelli A, et al. Rosa centifolia in a ‘non-scented’ moisturizing body lotion as a cause of allergic contact dermatitis, 2009

17. Fritz TM, et al. Allergic contact dermatitis to cosmetics containing Melaleuca alternifolia (tea tree oil), 2001

18. Pazzaglia M, et al. Allergic contact dermatitis due to avena extract, 2000

19. Sanchez-Perez J, et al. Allergic contact dermatitis from hydrolyzed wheat protein in cosmetic cream, 2000

20. Shaffrali FC, et al. Contact dermatitis from soybean extract in a cosmetic cream, 2001

21. Sahoo B, et al. Contact anaphylaxis due to hair dye, 2000

22. Bourrain JL, et al. Contact urticaria photoinduced by benzophenones, 2003

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36. European Parliament. Opinion Concerning a Clarification on the Formaldehyde and Para-Formaldehyde Entry in Directive 76/768/eec on Cosmetic Products, 2002

37. Pidoux G, et al. Formaldehyde Crosses the Human Placenta and Affects Human Trophoblast Differentiation and Hormonal Functions, 2015

38. Han SP, et al. Formaldehyde exposure induces autophagy in testicular tissues of adult male rats, 2015

39. Wang HX, et al. Effects of low-dose, long-term formaldehyde exposure on the structure and functions of the ovary in rats, 2013

40.Bernauer U, et al. Opinion of the Scientific Committee on Consumer Safety (SCCS) — Revision of the opinion on o-Phenylphenol, Sodium o-phenylphenate and Potassium o-phenylphenate (OPP), in cosmetic products, 2016

41. Cavanagh JE, et al. Assessment of endocrine disruption and oxidative potential of bisphenol-A, triclosan, nonylphenol, diethylhexyl phthalate, galaxolide, and carbamazepine, common contaminants of municipal biosolids, 2018

42. Schreurs RH, et al. Interaction of polycyclic musks and UV filters with the estrogen receptor (ER), androgen receptor (AR), and progesterone receptor (PR) in reporter gene bioassays, 2005

43. Schreurs RH, et al. Transcriptional activation of estrogen receptor ERalpha and ERbeta by polycyclic musks is cell type dependent, 2002

44. Gibson EA, et al. Effects of Polybrominated Diphenyl Ethers on Child Cognitive, Behavioral, and Motor Development, 2018

45. Acir IH, et al. Endocrine-disrupting metabolites of alkylphenol ethoxylates — A critical review of analytical methods, environmental occurrences, toxicity, and regulation, 2018

46. Hong F, et al. Exposure to TiO2 Nanoparticles Induces Immunological Dysfunction in Mouse Testitis, 2016

47. Gomez E, et al. Estrogenic activity of cosmetic components in reporter cell lines: parabens, UV screens, and musks, 2005

48. Patisaul HB. Endocrine disruption by dietary phyto-oestrogens: impact on dimorphic sexual systems and behaviours, 2017

49. Ota Y, et al. A 55-week chronic toxicity study of dietary administered kojic acid (KA) in male F344 rats, 2009

50. Kassotis CD, et al. Estrogen and androgen receptor activities of hydraulic fracturing chemicals and surface and ground water in a drilling-dense region, 2014

51. Calsolaro V, et al. Thyroid Disrupting Chemicals, 2017

52. Concin N, et al. Evidence for cosmetics as a source of mineral oil contamination in women, 2011

53. Toklu HZ, et al. Cosmetovigilance: A review of the current literature, 2019

54. St Sauver JL, et al. Why patients visit their doctors: assessing the most prevalent conditions in a defined American population, 2013

55.Vigan M, et al. Cosmetovigilance: definition, regulation and use “in practice”, 2014

Photo: Nataliya Melnychuk on Unsplash; Design: BOOST Thyroid