You probably know that your hormones fluctuate both during your period and over your lifetime. But, you might not realize the many ways that these hormones can affect your skin. And some of those skin changes could point to underlying health problems, including insulin resistance.YouBeauty talked to Rebecca Booth, M.D., an obstetrician and gynecologist and author of The Venus Week, and Steven Petak, M.D., an endocrinologist at the Texas Institute for Reproductive Medicine and Endocrinology, to find out what’s happening hormonally at each stage of life, how it impacts the skin and your overall health, and what you can do to help your skin look its best throughout your lifetime.

Teens: The Oily Years

Girls start puberty around ages 12 or 13, although the precise timing is influenced by both genetic and environmental factors. During puberty, the female body starts producing sex hormones, namely estrogens and androgens, in higher quantities than before as it gears up towards adulthood. Both can dramatically affect the skin (the body also ramps up production of other hormones related to reproduction, including progesterone, but these don’t impact the skin so we’ll skip them for this discussion).

READ MORE: The Best Way to Treat Acne for Your Skin Type

Estrogen is generally considered the female hormone, but it is present in both sexes — females just have higher levels. It is responsible for what we consider the “feminine aesthetic,” explains Dr. Booth. In females, estrogen comes mainly from the ovaries, where it serves to ripen the eggs that are later shed during each menstrual cycle, usually just one egg per cycle. During puberty, estrogen also communicates to other parts of the body through specialized receptors, causing breasts to develop, for example, or giving a new curve to hips and thighs. In the skin, estrogen decreases pore size, creating a smooth surface. It also helps build collagen and elastin, proteins that give the skin its springiness and elasticity, respectively. And, it helps the skin heal and maintain moisture.

Androgens include testosterone, which is generally thought of as the male hormone, but, as with estrogen and males, testosterone and other androgens are also present in females. During puberty, a boost in androgens stimulates hair growth, particularly pubic and underarm hair. In the skin, the hormones enlarge pores and boost the production of sebum, an oily substance produced in the skin.What you get is the telltale sign of teenage skin: acne.

QUIZ: What’s Your “Skin Age”?

Both estrogen and androgens surge right before ovulation, which is when the ovary releases an egg. But in young girls, the levels might not peak at just the right times, explains Booth: “The irregularity of signals from the immature ovary leads often to a hormonal imbalance,” and if testosterone dominates, the resulting increase in pore size and oily skin provides the perfect breeding ground for acne-causing bacteria.

20s to Mid-30s: The Best of Times 

The hormonal cycles eventually even out. During the 20s, 30s and early 40s, most women will experience a regular menstrual cycle of about 28 days, although the timing varies for each woman. Diet, exercise, and various diseases and disorders also influence the cycle’s regularity, as well as hormone levels.

READ MORE: A Sweet Scrub To Leave Your Skin Soft and Smooth

If the cycle remains on schedule, estrogen peaks right before ovulation, which can make the skin appear to glow (this is the same hormonal boost that gives pregnant women their shining skin). Testosterone also peaks, but it is tempered by the increase in estrogen when a woman’s hormones are in balance. Instead of producing oily skin and increasing the chances for an acne breakout, testosterone’s sebum boost gives the skin a luminous glow. The hormone also increases the libido.After ovulation, both estrogen and testosterone drop. During this time, says Booth, the decrease in estrogen causes a slight decrease in collagen and elastin so that the skin is slightly less springy and youthful. Once the next cycle starts and estrogen rises again, the skin bounces back.

Late 30s and 40s: Getting Drier 

The estrogen effect peaks around age 25, then drops slightly in the 30s and more significantly in the 40s. As the overall level of estrogen decreases, the skin does not bounce back the same way it does during each menstrual cycle. Instead, collagen and elastin production decreases, which causes the skin to get drier and loose its elasticity. The loss of estrogen impacts aging skin far more quickly than sun damage.

By their mid-to-late 40s, most women are in perimenopause, the transition between regular ovulation and menopause, which is when ovulation stops completely. As the hormone cycles change to accommodate this new stage, women in this age group may experience adult acne, increased facial hair and thinning scalp hair.

50s and Up: Menopause Realities 

By the time most women reach 50, they are in menopause, and ovulation has stopped. The ovaries still produce hormones, including estrogen and testosterone, but the levels are far lower than before.The main hormone that affects the skin during menopause is estrogen and, as it fades, the skin produces less collagen and elastin. In fact, writes Booth in The Venus Week, one study found that collagen production decreases 2.1% each year in the 15 years that follow menopause, which means an average of a 30% decrease in collagen between ages 50 and 65. During this time, the skin gets thinner, drier and more wrinkled. Menopause may cause other skin problems, including acne or rosacea, a chronic skin disorder resembling acne that can cause the skin to redden and swell.

READ MORE: What Anti-Aging Routine Should You Use?

Drops in estrogen can also cause hot flashes, which affect around three-quarters of women at the start of menopause and almost a third over the following five years. The hot flashes can cause a sudden sensation of warmth in the face and chest, and sometimes cause flushing.

Other Causes of Imbalanced Hormones 

Both Dr. Booth and Dr. Petak warn that a poor diet—especially one high in sugars and starches—can throw off the balance between estrogen and testosterone, exacerbating skin problems. Western diets high in carbohydrates and processed foods cause the body to produce too much insulin, another hormone, which regulates blood sugar levels. Insulin levels spike after you eat sugars, and sustained levels from consistently eating sugary foods can lead to insulin resistance, often a precursor to diabetes.Insulin resistance can also be a key factor in polycystic ovary syndrome (PCOS), in which the body produces abnormally high levels of androgens. The insulin throws the ovarian hormones off balance by over-stimulating the production of testosterone, which can lead to excess hair growth, including on the face and chest, and oily skin and related acne. It can also cause irregular or absent periods, hair loss (from the scalp), infertility and ovarian cysts.“These cosmetic changes in hair and skin really may be indications of serious underlying conditions that should be fully evaluated, not just covered up,” explains Dr. Petak, who recommends a visit with a specialist if symptoms like these persist. “It’s important to be aware that this is representative of an underlying problem.”PCOS is most commonly diagnosed in women in their 20s or 30s, but symptoms often begin during puberty. It affects between 4 to 18 percent of women.

Getting Hormones Under Control 

Altering your diet can help prevent insulin resistance, and therefore can stave off PCOS. Dr. Booth recommends avoiding sugary foods, like white breads, crackers, pasta, and rice, and replacing them with whole grain substitutes. Low-fat proteins such as fish, poultry or plant-based options such as tofu or legumes, are a better protein choice over red meat or cured meats like sausage and cold cuts. And, fruits and vegetables, especially those high in fiber and low in sugar, are a must.Even women who don’t suffer from PCOS can benefit from watching their diet and exercising. Being overweight and avoiding exercise can affect hormone levels, which can in turn impact the skin and overall health. But, don’t go overboard: underweight women and those who over-exercise are also at risk.  Instead, aim for a body mass index between 20-25, says Dr. Petak.

READ MORE: Skincare Rockstars: 7 Ingredients Your Skin Needs Now

For routine skin care, women—particularly those in their teens and 20s—can help control oily skin and related acne by using daily face cleansers that include salicylic acid. Older women who have lower estrogen levels and the related decrease in skin elasticity and increase in dryness might try a weekly exfoliant to slough off dead skin, as well as an antioxidant moisturizer. And, for wrinkles, retinoids can help. Of course, women of all ages should make sure to wear sunscreen. While this won’t impact the hormonal changes, sun damage can exacerbate some of the changes in the skin, including wrinkles.

Most important, perhaps, is understanding how hormones can affect both your skin and your health, says Dr. Booth:

“Women must first understand the effects of their hormones on skin and overall health to empower them to seek lifestyle changes to navigate these natural fluctuations. With the power of knowledge, they can seek solutions to achieve the maximum glow of hormonal balance all month long and all life long.”