If you've ever experienced time-of-the-month breakouts, you know all too well about the close relationship between hormones and skin. What you probably didn't realize, however, is that you have your cycle to thank when your skin looks good, too.

"Women are supposed to have a different appearance throughout the month," says Rebecca Booth, MD, a gynecologist and author of "The Venus Week." "Mother Nature designed us to look better when we are more fertile." Therefore, higher estrogen levels generally equate to better-looking skin.

Even if you haven't had a pimple in 10 years, your hormones are constantly affecting your skin -- and how they do it is directly related to your age. "Most women reach peak fertility -- and peak collagen production -- at about age 27," says Booth. "Then it starts a gradual decline that picks up speed around ages 35, 42, and finally menopause." Understanding the relationship between your estrogen levels and your skin can help you deal with both the changes over the course of the month and the changes throughout your life. By making the most of your collagen-producing days, you'll see long-term benefits.

Skip ahead to find out how you should change your skin care with your cycle.

Unfortunately, if you're on The Pill the same rules don't apply. "The birth control pill is often credited with curing acne," explains Booth. "And it works. But it also mutes the good days -- making them harder to detect." And even though fluctuations still exist, those in the know suggest sticking with a regular regimen throughout the month.

To make the most of how your hormones and skin jibe, follow these eight tips and have a vibrant complexion all month long.

Cycle Day One corresponds to the first day of your period, at which point your hormones are very low. "You feel a little washed out," explains Booth. "And you may assume it's from blood loss, but there are also chemicals called prostaglandins that cause the run-down feeling by increasing inflammation." These prostaglandins are lipids that are released by our cells -- and they contribute to puffy, blotchy skin during the first few days of your cycle.

To help soothe your skin, use a moisturizer that contains anti-inflammatory ingredients like green tea, chamomile, or feverfew. Try Aveeno Ultra Calming Daily Moisturizer, $14.99.

Prostaglandins are also responsible for making your skin appear dull. "They give the skin a pallor," says Booth. "And low estrogen levels don't help either." However, you can fake a glow by using a serum, moisturizer, or foundation that contains light-reflecting particles. The newly launched SK-II Cellumination Essence SX, $150, has a pearlescent quality that makes your skin look deceptively smooth and radiant -- even if it isn't.

Do you sometimes marvel at how amazing your skin looks? Rest assured that it's not just good lighting or the serum you put on the night before. "A cycling woman will have her best skin days when her estrogen is at its highest," says Booth. "This occurs right before ovulation -- when she's at her most fertile." Pores are at their smallest, and your skin is more hydrated -- making it glow. Even collagen production increases during this time of the month.

"The Venus Week," the title of Booth's book, refers to this optimal phase of a woman's cycle. Booth suggests becoming aware of this particular time so that you can fully enjoy it. "This is the week to go without makeup," she says. "There's no better aphrodisiac than feeling good about your appearance."

After ovulation, your estrogen begins to decline, taking your glowing skin with it. This is the time to tweak your skin care routine to keep the "good skin" days going and minimize the bad ones. "Switch to a mild, fragrance-free, non-comedogenic cleanser that won't irritate your skin," says Los Angeles dermatologist Ava Shamban, MD. Cetaphil Daily Facial Cleanser, $10, is a dermatologist favorite. Booth suggests using a mild exfoliant with increased frequency during the days leading up to the first day of your period.