This article is part of LUMI’s ongoing collaboration with Happy Aging Clinic, Estonia’s premier preventive medical clinic. Just like LUMI, Happy Aging are committed to providing science-backed solutions for the prevention of premature aging, without the use of cosmetic surgery!

 

From the moment we’re born into this world, through to our final farewells, there is only one constant in our lives – change. 

The world is continually shifting as we navigate our path through it, and our own bodies experience perhaps the most drastic changes of all: the explosive growth of childhood; the difficulties of adolescence; the newfound responsibility of adulthood; and, of course, the unique challenges of our later years. 

These fundamental transformations are controlled by the same biological force – hormones! Hormones tell our body what to do: to grow, to repair, to begin this process, or cease that one. They control everything from sleep, to menstruation, to how tall we grow in childhood. All of us will feel hormones’ effect on our bodies on a regular basis, but how much do we really understand what’s going on?

This is especially pertinent when it comes to hormones and skin. Just like the rest of the body, hormones have a huge impact on the appearance and performance of our skin in both the short and long term. Despite this, many skin-savvy people have a blind spot when it comes to such matters. They might not know the full effects of these compounds on their skin, or know how treatable many of the issues caused by hormonal changes can be. Well, we say no longer! It’s time to give you the facts you need to help your skin!

Today, we delve into some of the myriad ways that hormones can affect our skin, from the causes of teenage acne, all the way through to how menopause can accelerate skin aging. We’ll stop off on the way to talk about pregnancy hormones, and we’ll also discuss the often-ignored topic of male hormones and skin (fear not, gentlemen readers – LUMI is for everyone!). 

Finally, we’ll show you how you can help your skin deal with hormonal changes, with a helping hand from LUMI and our collaborative partners, the brilliant Happy Aging Clinic. But more on that later – let’s begin!

The Incredible Endocrine System

Before getting into hormones’ effects on skin, it’s worth briefly summarising exactly what hormones are, as well as how and why they’re created. Earlier on we said that hormones are responsible for many of the most dramatic changes we experience in our bodies. Whilst this is technically true, it’s probably more useful to say that the endocrine system is responsible. 

The endocrine system is a complex web of organs and tissues throughout the body that produces and releases hormones to maintain homeostasis (proper bodily functioning) or to enact some kind of change. Creating hormones is the primary purpose of organs such as the thyroid and the adrenal glands; other hormones are also created as a secondary function by some types of tissue, including bone and body fat.

Hormones themselves are microscopic chemical structures that mix into the bloodstream, travelling throughout the body until they reach their target. Once delivered, hormones can order parts of the body to behave in a certain way: melatonin tells the body it’s time to sleep; insulin helps control your blood sugar level; and adrenaline increases your heart rate and prepares the body for fight or flight!

The endocrine system is a brilliant piece of bioengineering, and hormones are vital to almost everything we do as humans. They’re a marvel, and we wouldn’t last a day without them. That doesn’t mean, however, that everything hormones do to our body is welcome – sometimes, hormones can be a real pain!

Growing Pains

One of the most universal experiences of growing up is dreaded teenage acne. This embarrassing and unwelcome skin issue affects the vast majority of those going through puberty and into adolescence. Ultimately, the acne is caused by hormones released by the adrenal cortex and the reproductive organs, which stimulate the production of sebum (an oily substance that helps skin stay moisturised). 

This overabundance of sebum clogs pores, makes the skin oily, and provides the perfect conditions for bacteria to flourish. The most common bacteria to be found is Cutibacterium acnes, which is named after the condition. As a response, the body’s immune system kicks into gear, causing the painful pimples we all know so well.

Acne caused by these hormone changes can be hard to shift, because the underlying cause of sebum overproduction cannot be addressed, as its vital for our body’s development into an adult. Instead, treatment has to focus on exfoliating the skin to remove excess sebum and dead skin cells, as well as antibacterial agents in severe cases.

As well as acne, the influx of sex hormones during puberty can cause a number of less common skin issues. The increase in sebum can lead to seborrheic dermatitis (dandruff is a mild form of the condition), and the onset of puberty is also thought to be a potential trigger for the onset or worsening of psoriasis and several other autoimmune or autoinflammatory conditions. 

20% of girls will suffer hair loss whilst going through puberty – the number is slightly higher for boys, and it is even possible for baldness to begin at this very early stage in life! All in all, then, puberty can be an incredibly tough time for children’s mental and physical health. It’s a necessary part of the journey into adulthood, but that doesn’t make it any less difficult for those stuck in the middle of a hormonal hurricane!

Giver of Life… and Destroyer of Skin Peace!

There is perhaps no greater example of the admirable complexity of the endocrine system than the menstrual cycle. The repeating loop of preparation, ovulation, and anticipation is primarily controlled by the female sex hormones estrogen and progesterone, which in turn cause the levels of more specialised hormones to rise and fall. It’s one of the natural world’s most brilliant systems, and quite simply, none of us would be here without it!

Unfortunately, it’s not all upside. The great rises and falls of estrogen and progesterone that are necessary for stimulating the stages of the menstrual cycle are also strong enough to play havoc with our bodies. Research suggests that peak levels of progesterone in the body (midway through the luteal phase, around day 21 of 28) are a major cause of flare-ups for a host of common skin conditions, including acne, psoriasis, and atopic dermatitis.

Sex hormone changes are also thought to make the skin more susceptible to hyperpigmentation (patches of skin becoming darker than the skin around them), which again occurs most frequently during the luteal phase. The most commonly reported type of hyperpigmentation was melasma, which typically affects facial skin. In addition, researchers found that a significant proportion of women (between a quarter and a third of those surveyed) experience heightened skin sensitivity before or during menstruation.

As if all that wasn’t enough to deal with, it’s also thought that an irregular menstrual cycle can contribute to a decreased level of skin hydration, barrier integrity, and microbiome diversity, as well as an increase in sebum levels. It’s an awful lot to have to go through whilst those very same hormonal changes affect your mood, energy levels, and may also cause pain!

Forty Wild Weeks for Expecting Mums and Their Skin

Even when the menstrual cycle temporarily ceases for pregnancy, women are still at the mercy of strong hormonal fluctuations throughout the body. 90% of pregnant women will experience significant changes to their skin, primarily due to hormones. And whilst we may often talk in popular culture about the ‘pregnancy glow’ that leaves expecting mothers looking so radiant, the reality of the situation can often be far more challenging.

Pregnancy-derived skin changes can manifest as the reappearance or worsening of preexisting skin conditions, such as acne, psoriasis, and hidradenitis suppurativa, or as entirely new complaints. These new skin developments may be benign (but still unwelcome) changes such as hyperpigmentation, stretch marks, and skin reddening, or they can be more serious conditions, such as pregnancy-specific variants of pustular psoriasis and intrahepatic cholestasis (a serious liver issue that causes itching on the skin, amongst many other problems).

Treatment for hormonal skin conditions during pregnancy is greatly complicated by the need to ensure that both mother and baby are kept as safe and healthy as possible. 

Because of this, even fairly everyday solutions such as topical corticosteroid creams are advised to be avoided for skin complaints until postpartum. Indeed, once pregnancy is over, many women find that most of their skin changes resolve on their own, though it is still extremely common for conditions such as hyperpigmentation to stick around, longer after the hormones that caused them have calmed down!

An Estrogen Exodus – The Struggles of Menopausal Skin

We’ve covered the effects of menopause on skin at length in our blog on the subject, but it’s worth reiterating some of that information here, too!

Menopause occurs when the female body’s ovaries begin to slow down their production of the sex hormone estrogen (usually around the age of 50, though a significant amount of women will begin menopause years earlier).

Perimenopause, which may begin up to a decade before menopause, is the transitional phase where hormone levels start to fluctuate, and the first noticeable changes in the body appear. During this time, women often experience various symptoms, including skin-related issues, as estrogen levels begin to decline.

“There are two main hormones that impact us: estrogen and progesterone. During puberty, the levels of these hormones rise, but in perimenopause, they decrease. Think of perimenopause as puberty in reverse, with hormone levels fluctuating,” explains Dr. Lesdorf.

Eventually, the ovaries will cease to produce any estrogen for the body whatsoever, resulting in an estrogen deficiency. This causes a host of issues for skin that were historically put down simply to the effects of aging, but are now better understood.

The amount of collagen, a vital structural protein for skin, present in menopausal women significantly declines. The average woman’s skin loses roughly 30% of its collagen during the first five years of menopause, and a further 2% every year for the following twenty years. This lack of collagen leads to visual changes such as more pronounced wrinkles, saggier skin, and larger pores, as well as reducing skin barrier function and wound healing capabilities.

It’s not just a lack of collagen that menopausal women need to be aware of, though! It’s very common for estrogen deficiency to increase the likelihood of skin conditions such as melasma (the facial hyperpigmentation we mentioned above), hypersensitivity, excessive sweating, itching, dryness, contact dermatitis to new allergens, and even menopausal acne – as if there wasn’t enough to contend with!

Fortunately, much of the change and accelerated aging caused by an estrogen deficiency can be remedied by restoring estrogen levels in the body. Hormone replacement therapy, or HRT, has become a commonplace treatment for estrogen deficiency that can repair some skin issues and stop the march of premature aging. Studies have shown that post-menopausal women who have estrogen supplementation have higher collagen levels, skin thickness and elasticity, and sebum levels than post-menopausal women who have no HRT.

Additionally, hormone replacement therapy can alleviate mood disorders associated with menopause, reduce the risk of osteoporosis-related fractures, and potentially ease joint pain. It also helps address genital tract issues such as cystitis, lowers the risk of type 2 diabetes, and may enhance cognitive function

It should be noted that HRT can carry increased risks of certain health issues and is not suitable for everyone. Seek the advice of a trusted medical professional before considering HRT. For most people, however, the risks of estrogen deficiency are thought to be more impactful than those associated with HRT. The UK’s National Health Service (NHS), for example, recommends that if you are a woman under 60 with menopause symptoms and do not have an increased risk of blood clots or breast cancer, then the benefits of HRT are likely to outweigh the associated risks.

Dr. Lesdorf notes that in today’s performance-driven world, women tend to visit the doctor only when their symptoms become severe, their quality of life significantly declines, and they feel truly unwell.

“You shouldn’t be afraid of hormone replacement therapy; moreover, it’s important to weigh the risks of untreated symptoms,” says Dr. Lesdorf. “For instance, prolonged sleep deprivation is linked to a higher risk of breast cancer. I would recommend hormone replacement therapy to any woman whose quality of life is significantly affected by menopausal symptoms.”

Of course, estrogen replacement cannot stop all menopause-related skin changes, and it cannot repair any permanent aging that has already occurred. That means that there is still a lot of value to be found in topical remedies that can help skin look and feel its best! This can include treatments that help restore skin structure and barrier function, re-hydrate skin with deep, lasting moisturisation, and minimise fine lines and wrinkles via added peptides. But more on all that and more in a moment!

Understanding Male Hormones and Andropause

Men might be thankful to avoid the monthly hormonal fluctuations of menstruation or the challenges of pregnancy, but they can still face great difficulties as sex hormones begin to decline in later life. This ‘andropause’ is rarely spoken about, but the consequences can have a profound impact on health and wellbeing, and should be taken seriously. 

Testosterone levels in men slowly decline as they age, in much the same way that estrogen tails off in women. This results in a decrease in skin thickness, moisture levels, and elasticity, which means skin is not able to perform its bodily functions as effectively and will also visibly age quicker. Research has found that testosterone levels correlate with severity of flare-up symptoms in male psoriasis patients (the lower the blood serum testosterone level, the more severe the symptoms).

Unlike female hormone replacement therapy, which has become fairly commonplace, male hormone replacement therapy is still yet to be fully explored. A major reason for this is that increased testosterone levels are associated with a number of risks, including an increased risk of cardiac events, such as a heart attack or stroke. Those with existing issues, such as diabetes or heart conditions, need to be especially cautious.

An academic review into the matter found that, whilst low testosterone levels can cause several health issues, the potential consequences of treatment outweighed the potential benefit for anyone who is not suffering from a severely reduced level of testosterone. Therefore, for most men, the solution to hormone-related aging of the skin should likely focus on minimising symptoms, rather than replacing hormones.

Help Your Skin Deal with Hormonal Changes with LUMI and Happy Aging Clinic!

So, it’s clear that hormonal changes can be quite the ride for our bodies, and certainly not least the skin! Fortunately, there are plenty of strategies available to help combat the majority of hormone-induced skin challenges that you may face throughout life.

Hormonal acne can rear its ugly head throughout life, and it never makes things easier. LUMI’s TUNDRA series is specially designed to fight acne at its source, helping to redress the moisture balance of skin, exfoliate its surface, and reduce sebum levels. The triple effect of TUNDRA’s cleansing milk, yarrow mist toner, and AHA-BHA acid-infused moisturising cream helps you regain control over problematic skin, no matter your age or individual skin needs! 

The loss of collagen and increase in sensitivity and hyperpigmentation associated with estrogen deficiency can make an already challenging time of your life even harder to manage. 

Fortunately, these skin issues respond well to topical treatments! LUMI’s Collagen Booster is a comprehensive solution to several of the problems estrogen deficiency can pose. The growth factor-like postbiotic spermidine is highly valued for its ability to stimulate collagen production in cells, whilst hyaluronic acid of varying molecular weights support this process whilst also providing deep and lasting hydration. Collagen peptides are also included to ensure that your body has all the raw materials it needs to build back better!

Hormonal Diagnostics

A well-regulated hormonal system is fundamental to sustaining optimal health and well-being.

At the Happy Aging Clinic, hormone balance assessments are specifically tailored for young women, mature women, and men, addressing the unique needs of each group. The clinic also provides the DUTCH test, a comprehensive analysis designed to detect hormonal imbalances across all age groups, particularly for individuals presenting symptoms suggestive of hormone-related disorders. For cases requiring a more nuanced approach, personalized testing packages can be arranged based on insights gained during the doctor’s consultation.

The clinic’s commitment to a personalized, holistic approach is reflected in every analysis package, which includes a detailed written consultation from the physician (DIGILUGU). This consultation offers a thorough interpretation of the test results, presented in clear, accessible language to facilitate informed decision-making regarding your health. With this level of support, you can confidently navigate the next steps in your wellness journey!

The partnership between LUMI and the Happy Aging clinic brings together the perfect blend of expertise and care, providing your skin and body with exactly what they need. This unique synergy empowers you to radiate confidence, vitality, and beauty at every stage of life, allowing your true self to shine through naturally and effortlessly.

References

1. Allam, J. P., Bunzek, C., Schnell, L., Heltzel, M., Weckbecker, L., Wilsmann-Theis, D., Brendes, K., Haidl, G., & Novak, N. (2019). Low serum testosterone levels in male psoriasis patients correlate with disease severity. European journal of dermatology: EJD, 29(4), 375–382. https://doi.org/10.1684/ejd.2019.3605 

2. Aref, Y., Fat, S. C., & Ray, E. (2024). Recent insights into the role of hormones during development and their functional regulation. Frontiers in endocrinology, 15, 1340432. https://doi.org/10.3389/fendo.2024.1340432 

3. Bergler-Czop, B., & Brzezińska-Wcisło, L. (2013). Dermatological problems of the puberty. Postepy dermatologii i alergologii, 30(3), 178–187. https://doi.org/10.5114/pdia.2013.35621 

4. Bernard, P., Scior, T., & Do, Q. T. (2012). Modulating testosterone pathway: a new strategy to tackle male skin aging? Clinical interventions in aging, 7, 351–361. https://doi.org/10.2147/CIA.S34034 

5. Calleja-Agius, J., & Brincat, M. (2012). The effect of menopause on the skin and other connective tissues. Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology, 28(4), 273–277. https://doi.org/10.3109/09513590.2011.613970 

6. Campbell, M., & Jialal, I. (2022). Physiology, Endocrine Hormones. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/30860733/ 

7. Ceovic, R., Mance, M., Bukvic Mokos, Z., Svetec, M., Kostovic, K., & Stulhofer Buzina, D. (2013). Psoriasis: female skin changes in various hormonal stages throughout life–puberty, pregnancy, and menopause. BioMed research international, 2013, 571912. https://doi.org/10.1155/2013/571912 

8. Chu, B., Marwaha, K., Sanvictores, T., Awosika, A. O., & Ayers, D. (2024). Physiology, Stress Reaction. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/31082164/ 

9. Erlandson, M., Wertz, M. C., & Rosenfeld, E. (2023). Common Skin Conditions During Pregnancy. American family physician, 107(2), 152–158. https://pubmed.ncbi.nlm.nih.gov/36791447/ 

10. Falcone, D., Richters, R. J., Uzunbajakava, N. E., Van Erp, P. E., & Van De Kerkhof, P. C. (2017). Sensitive skin and the influence of female hormone fluctuations: results from a cross-sectional digital survey in the Dutch population. European journal of dermatology : EJD, 27(1), 42–48. https://doi.org/10.1684/ejd.2016.2913 

11. Kar, S., Krishnan, A., & Shivkumar, P. V. (2012). Pregnancy and skin. Journal of obstetrics and gynaecology of India, 62(3), 268–275. https://doi.org/10.1007/s13224-012-0179-z 

12. Knight, J. (2021). Endocrine system I: overview of the endocrine system and hormones. Nursing Times [online]; 117: 5, 38-42. https://www.nursingtimes.net/primary-care/endocrine-system-1-overview-of-the-endocrine-system-and-hormones-26-04-2021/ 

13. Kurien, G., Carlson, K., & Badri, T. (2024). Dermatoses of Pregnancy. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/28613614/ 

14. Ma, L., Jiang, H., Han, T., Shi, Y., Wang, M., Jiang, S., Yang, S., Yao, L., Jia, Q., & Shao, L. (2023). The menstrual cycle regularity and skin: irregular menstrual cycle affects skin physiological properties and skin bacterial microbiome in urban Chinese women. BMC women’s health, 23(1), 292. https://doi.org/10.1186/s12905-023-02395-z 

15. McLaughlin, M. B., & Jialal, I. (2023). Biochemistry, Hormones. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/31082156/ 

16. Mobasher, P., Foulad, D. P., Raffi, J., Zachary, C., Fackler, N., Zohuri, N., Juhasz, M., & Atanaskova Mesinkovska, N. (2020). Catamenial Hyperpigmentation: A Review. The Journal of clinical and aesthetic dermatology, 13(6), 18–21. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7442313/ 

17. Motosko, C. C., Bieber, A. K., Pomeranz, M. K., Stein, J. A., & Martires, K. J. (2017). Physiologic changes of pregnancy: A review of the literature. International journal of women’s dermatology, 3(4), 219–224. https://doi.org/10.1016/j.ijwd.2017.09.003 

18. Owen, C. M., Pal, L., Mumford, S. L., Freeman, R., Isaac, B., McDonald, L., Santoro, N., Taylor, H. S., & Wolff, E. F. (2016). Effects of hormones on skin wrinkles and rigidity vary by race/ethnicity: four-year follow-up from the ancillary skin study of the Kronos Early Estrogen Prevention Study. Fertility and sterility, 106(5), 1170–1175.e3. https://doi.org/10.1016/j.fertnstert.2016.06.023 

19. Pillarisetty, L. S., & Sharma, A. (2023). Pregnancy Intrahepatic Cholestasis. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/31855347/ 

20. Putra, I. B., Jusuf, N. K., & Dewi, N. K. (2022). Skin Changes and Safety Profile of Topical Products During Pregnancy. The Journal of clinical and aesthetic dermatology, 15(2), 49–57. https://pubmed.ncbi.nlm.nih.gov/35309882/ 

21. Raghunath, R. S., Venables, Z. C., & Millington, G. W. (2015). The menstrual cycle and the skin. Clinical and experimental dermatology, 40(2), 111–115. https://doi.org/10.1111/ced.12588 

22. Reed, B. G., & Carr, B. R. (2018). The Normal Menstrual Cycle and the Control of Ovulation. In K. R. Feingold (Eds.) et. al., Endotext. MDText.com, Inc. https://www.ncbi.nlm.nih.gov/books/NBK279054/ 

23. Satish, N., Dakshinamoorthy, A., & S, S. (2022). A study of the pattern of dermatoses in adolescent patients in South India. International journal of dermatology, 61(3), 299–305. https://doi.org/10.1111/ijd.15602 

24. Shah, M. G., & Maibach, H. I. (2001). Estrogen and skin. An overview. American journal of clinical dermatology, 2(3), 143–150. https://doi.org/10.2165/00128071-200102030-00003 

25. Thiyagarajan, D. K., Basit, H., & Jeanmonod, R. (2022). Physiology, Menstrual Cycle. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/29763196/ 

26. Thornton M. J. (2013). Estrogens and aging skin. Dermato-endocrinology, 5(2), 264–270. https://doi.org/10.4161/derm.23872 

27. Vora, R. V., Gupta, R., Mehta, M. J., Chaudhari, A. H., Pilani, A. P., & Patel, N. (2014). Pregnancy and skin. Journal of family medicine and primary care, 3(4), 318–324. https://doi.org/10.4103/2249-4863.148099 

28. Yabluchanskiy, A., & Tsitouras, P. D. (2019). Is Testosterone Replacement Therapy in Older Men Effective and Safe?. Drugs & aging, 36(11), 981–989. https://doi.org/10.1007/s40266-019-00716-2

Viited:

1. Allam, J. P., Bunzek, C., Schnell, L., Heltzel, M., Weckbecker, L., Wilsmann-Theis, D., Brendes, K., Haidl, G., & Novak, N. (2019). Low serum testosterone levels in male psoriasis patients correlate with disease severity. European journal of dermatology: EJD, 29(4), 375–382. https://doi.org/10.1684/ejd.2019.3605 

2. Aref, Y., Fat, S. C., & Ray, E. (2024). Recent insights into the role of hormones during development and their functional regulation. Frontiers in endocrinology, 15, 1340432. https://doi.org/10.3389/fendo.2024.1340432 

3. Bergler-Czop, B., & Brzezińska-Wcisło, L. (2013). Dermatological problems of the puberty. Postepy dermatologii i alergologii, 30(3), 178–187. https://doi.org/10.5114/pdia.2013.35621 

4. Bernard, P., Scior, T., & Do, Q. T. (2012). Modulating testosterone pathway: a new strategy to tackle male skin aging? Clinical interventions in aging, 7, 351–361. https://doi.org/10.2147/CIA.S34034 

5. Calleja-Agius, J., & Brincat, M. (2012). The effect of menopause on the skin and other connective tissues. Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology, 28(4), 273–277. https://doi.org/10.3109/09513590.2011.613970 

6. Campbell, M., & Jialal, I. (2022). Physiology, Endocrine Hormones. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/30860733/ 

7. Ceovic, R., Mance, M., Bukvic Mokos, Z., Svetec, M., Kostovic, K., & Stulhofer Buzina, D. (2013). Psoriasis: female skin changes in various hormonal stages throughout life–puberty, pregnancy, and menopause. BioMed research international, 2013, 571912. https://doi.org/10.1155/2013/571912 

8. Chu, B., Marwaha, K., Sanvictores, T., Awosika, A. O., & Ayers, D. (2024). Physiology, Stress Reaction. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/31082164/ 

9. Erlandson, M., Wertz, M. C., & Rosenfeld, E. (2023). Common Skin Conditions During Pregnancy. American family physician, 107(2), 152–158. https://pubmed.ncbi.nlm.nih.gov/36791447/ 

10. Falcone, D., Richters, R. J., Uzunbajakava, N. E., Van Erp, P. E., & Van De Kerkhof, P. C. (2017). Sensitive skin and the influence of female hormone fluctuations: results from a cross-sectional digital survey in the Dutch population. European journal of dermatology : EJD, 27(1), 42–48. https://doi.org/10.1684/ejd.2016.2913 

11. Kar, S., Krishnan, A., & Shivkumar, P. V. (2012). Pregnancy and skin. Journal of obstetrics and gynaecology of India, 62(3), 268–275. https://doi.org/10.1007/s13224-012-0179-z 

12. Knight, J. (2021). Endocrine system I: overview of the endocrine system and hormones. Nursing Times [online]; 117: 5, 38-42. https://www.nursingtimes.net/primary-care/endocrine-system-1-overview-of-the-endocrine-system-and-hormones-26-04-2021/ 

13. Kurien, G., Carlson, K., & Badri, T. (2024). Dermatoses of Pregnancy. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/28613614/ 

14. Ma, L., Jiang, H., Han, T., Shi, Y., Wang, M., Jiang, S., Yang, S., Yao, L., Jia, Q., & Shao, L. (2023). The menstrual cycle regularity and skin: irregular menstrual cycle affects skin physiological properties and skin bacterial microbiome in urban Chinese women. BMC women’s health, 23(1), 292. https://doi.org/10.1186/s12905-023-02395-z 

15. McLaughlin, M. B., & Jialal, I. (2023). Biochemistry, Hormones. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/31082156/ 

16. Mobasher, P., Foulad, D. P., Raffi, J., Zachary, C., Fackler, N., Zohuri, N., Juhasz, M., & Atanaskova Mesinkovska, N. (2020). Catamenial Hyperpigmentation: A Review. The Journal of clinical and aesthetic dermatology, 13(6), 18–21. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7442313/ 

17. Motosko, C. C., Bieber, A. K., Pomeranz, M. K., Stein, J. A., & Martires, K. J. (2017). Physiologic changes of pregnancy: A review of the literature. International journal of women’s dermatology, 3(4), 219–224. https://doi.org/10.1016/j.ijwd.2017.09.003 

18. Owen, C. M., Pal, L., Mumford, S. L., Freeman, R., Isaac, B., McDonald, L., Santoro, N., Taylor, H. S., & Wolff, E. F. (2016). Effects of hormones on skin wrinkles and rigidity vary by race/ethnicity: four-year follow-up from the ancillary skin study of the Kronos Early Estrogen Prevention Study. Fertility and sterility, 106(5), 1170–1175.e3. https://doi.org/10.1016/j.fertnstert.2016.06.023 

19. Pillarisetty, L. S., & Sharma, A. (2023). Pregnancy Intrahepatic Cholestasis. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/31855347/ 

20. Putra, I. B., Jusuf, N. K., & Dewi, N. K. (2022). Skin Changes and Safety Profile of Topical Products During Pregnancy. The Journal of clinical and aesthetic dermatology, 15(2), 49–57. https://pubmed.ncbi.nlm.nih.gov/35309882/ 

21. Raghunath, R. S., Venables, Z. C., & Millington, G. W. (2015). The menstrual cycle and the skin. Clinical and experimental dermatology, 40(2), 111–115. https://doi.org/10.1111/ced.12588 

22. Reed, B. G., & Carr, B. R. (2018). The Normal Menstrual Cycle and the Control of Ovulation. In K. R. Feingold (Eds.) et. al., Endotext. MDText.com, Inc. https://www.ncbi.nlm.nih.gov/books/NBK279054/ 

23. Satish, N., Dakshinamoorthy, A., & S, S. (2022). A study of the pattern of dermatoses in adolescent patients in South India. International journal of dermatology, 61(3), 299–305. https://doi.org/10.1111/ijd.15602 

24. Shah, M. G., & Maibach, H. I. (2001). Estrogen and skin. An overview. American journal of clinical dermatology, 2(3), 143–150. https://doi.org/10.2165/00128071-200102030-00003 

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