It’s summer, which means you’re probably on the go more than usual, with travel, parties, and spontaneous outings at every turn.

It’s all so much fun, but maybe you’ve noticed something unusual happening with your body this season. For example, maybe your cycle’s patterns have been off.

We’ve all heard that certain factors — like stress or hormonal shifts — can mess with your menstrual cycle. But what about the things you may be doing in the summer, like traveling, eating differently, and socializing more? Could they be responsible for changes you’re noticing?

Potentially — especially travel, according to Karla Loken, DO, an OB/GYN and VP of Medical Affairs and Clinical Operations at HerMD.

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Can travel impact your cycle?

In short? Yes.

“This is possible as a woman's cycle can respond to stress and sleep disruption,” says Dr. Loken. 

However, a packed vacation schedule doesn’t necessarily mean your period will be off schedule.

“Travel does not always affect a woman’s cycle, but it is logical to think that a stressful travel event or time change and extended travel might alter our cortisol response (stress hormone) and therefore send our cycle off by a day or so,” says Dr. Loken. “Usually travel will not cause a woman to miss her period so if this is the case it is important to check other causes of missed periods with a physician and rule out pregnancy.”

Is international travel more likely to affect your cycle?

When you travel overseas, different time zones and jet lag can make your whole schedule — not to mention sleep cycle — feel off. But is that likely to change your menstrual patterns?

“Only slightly,” says Dr. Loken. “And as previously mentioned, due to stress and change in environment.”

Can being ‘on the go’ more than usual disrupt your cycle?

Summer tends to be so much busier, with all the parties and trips you may have on your schedule. But generally just being more social and on the go is unlikely to directly affect your cycle, according to Dr. Loken. 

Can the summer heat affect your cycle?

“Most people do not see really big changes in cycles in summer vs. winter,” says Dr. Loken. 

But you may handle your menstrual hygiene differently due to the season. 

“In summer with swimming, heat, and humidity women may want to change or manage their personal hygiene products a bit more frequently, or switch up using tampons or a menstrual cup for swimming, more often than they do in the winter months,” she adds.

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Let’s clear up the myth about women’s cycles syncing up

Over the summer, chances are you’re around groups of friends far more often than usual. You may be wondering if the old adage about women’s cycles syncing up when they spend time together may be behind your own period’s change in pattern.

But according to Dr. Loken, this is just a myth.

“This has actually been studied and debunked in recent studies,” says Dr. Loken. “However, a dorm room of women will back up this claim - this was called The McClintock or Wellesley Effect (from women living in dormitories) and published in the early 1970’s. More current research has shown this to be false.”

Can changes in how you’re eating affect your cycle?

“Yes,” says Dr. Loken. Over the summer, your diet may be different (BBQ-ed burgers and ice cream on repeat, anyone?). This may change how your periods present.

“As we menstruate we lose blood. We should always be eating a balanced diet but making sure we have adequate iron intake in our diet is key for menstruating women,” adds Dr. Loken. “Also many diets have been recommended to decrease period symptoms like cramps and bloating: a high protein and fiber rich diet  can help control your blood sugar level, providing sustained energy may reduce  other cravings. Adding Omega-3/Fish oil may relieve menstrual cramps, depression and mood swing. Many cultures recommend herbs such as ginger and cinnamon to relieve menstrual pain. However, excessive intake should be avoided. Of course eating a balanced diet rich in vitamins and minerals without taking a lot of supplements is always the best option.”

When it comes to changes in someone's cycle, what's a "normal" delay? 

Obviously, there’s a difference between a period that comes a day or two late, as opposed to one that arrives a week after it’s expected (or not at all). So what’s a cause for concern vs. a “normal” variation?

“If a period is more than five-six days late or completely missed, sometimes women don’t realize until a second period is missed, so it's important to track cycles,” says Dr. Loken. “If you're late you should be evaluated by a doctor and of course if you're sexually active a missed cycle needs to be evaluated for potential pregnancy.”

Are there red flags to keep in mind when it comes to cycle irregularities?

“Multiple missed cycles or alternating missed cycles can be signs of metabolic changes or perimenopause,” says Dr. Loken. “If a period is off one month but resumes as normal it is not as big of deal as multiple missed cycles or cycles that are sporadic and at irregular intervals.”

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What other factors can affect your menstrual cycle patterns?

The most obvious thing is, of course, pregnancy.

“Early or missed pregnancy can delay a cycle, [as well as] early changes of perimenopause (the start of menopause), stress, sudden weight changes and endocrine changes like polycystic ovarian syndrome can cause period delay or changes,” says Dr. Loken.

Do people who typically have regular cycles still experience these travel-related changes?

This hasn’t been well-studied, but according to Dr. Loken, people who have regular cycles may be less likely to experience changes.

“This is not really studied that I can find, but super regular people usually stay regular despite travel and stress,” says the expert.


Zara Hanawalt is a freelance journalist and mom of twins. She's written for outlets like Parents, MarieClaire, Elle, Cosmopolitan, Motherly, and many others. In her (admittedly limited!) free time, she enjoys cooking, reading, trying new restaurants, and traveling with her family.