Why was everyone’s period late in June? An expert explains the viral TikTok theory

Earlier this month, TikTok creator Elizabeth Rose posted a video asking a question that struck a chord with thousands of women.

“I’m genuinely curious… did anyone else’s cycle seem completely different in June?”

The video goes on to claim that “thousands of women around the world’s period was missing or double at the same time for the whole month of June and it’s now July” — a theory that quickly gained traction as women flooded the comments with similar experiences.

The conversation became so widespread that even period tracking app Flo joined in on the trend, posting a tongue-in-cheek video referencing “a documentary” about women whose periods were “missing or doubled for the whole month of June”. The clip has since racked up more than 25,000 likes.

It’s not just happening on TikTok, either. Within the Her World team, several editors also shared that their menstrual cycles felt noticeably different in June, prompting the obvious question:

Was this simply social media amplifying a coincidence? Or was there actually something that could have caused so many women to experience changes at the same time?

So, what could have caused missed or irregular periods in June?

According to Dr Odelia Koh, Medical Director at Prologue – The Lifestyle Medical Clinic, there’s no evidence that a particular month can disrupt menstrual cycles on a global scale.

“I’d be cautious here – there isn’t credible clinical evidence that a calendar month itself alters hormone cycles across large populations,” she explains.

However, that doesn’t mean the experiences women are sharing aren’t real.

“One plausible reason is that June clusters real stress triggers: exam season, mid-year work crunches, school holiday travel and other lifestyle disruptions. Social media is also very good at making a coincidence feel like a pattern once enough people start comparing notes in comment sections.”

Stress can have a surprisingly big impact on your cycle

While it’s easy to dismiss stress as a catch-all explanation, Dr Koh says it’s one of the most common reasons she sees for delayed or missed periods.

“Your brain is extremely sensitive to perceived stress, whether it’s physical or psychological,” she says.

“Work stress, poor sleep, travel or intense physical activity can all delay or suppress ovulation, which pushes your period later or, in some cycles, skips it altogether.”

She adds that women juggling demanding careers, family responsibilities and busy schedules are particularly susceptible.

“The reassuring part is that this type of disruption is usually temporary and self-corrects once the underlying stressor settles.”

While stress often plays a role, it’s far from the only explanation. According to Dr Koh, common causes of missed or irregular periods include:

- Pregnancy
- Significant weight loss or weight gain
- Over-exercising
- Hormonal conditions such as polycystic ovary syndrome (PCOS)
-Thyroid disorders
- Endometriosis
- Perimenopause
- Hormonal contraception and certain medications

Less commonly, irregular periods can also be linked to premature ovarian insufficiency or structural reproductive issues.

“Nutritional deficiencies, particularly in women following restrictive diets, can suppress ovulation even without dramatic weight loss,” she adds.

Similarly, combining intense exercise with inadequate calorie intake can result in functional hypothalamic amenorrhoea, where the body temporarily stops ovulating.

Your menstrual cycle is often an early warning sign

One misconception Dr Koh frequently encounters is the belief that periods exist separately from the rest of our health.

“As a lifestyle medicine clinic, we’re trained to look upstream at factors like nutrition, movement patterns, chronic stress load, sleep debt and alcohol intake while also assessing medical causes like hormones,” she says.

“A cycle is often one of the first systems in the body to signal that something in daily life is unsustainable, well before other symptoms show up.”

She also points out that many women still believe a “normal” menstrual cycle must be exactly 28 days.

“In reality, anywhere from 21 to 35 days is medically normal.”

An occasional delayed period isn’t usually a cause for alarm. However, Dr Koh recommends making an appointment if you’ve missed three periods in a row, or if your cycles become consistently irregular over several months.

She also advises seeking medical advice sooner if the change is sudden and unusual for you, rather than part of your typical cycle.

Certain symptoms shouldn’t be ignored, including:

- Significant pelvic pain
- Very heavy or prolonged bleeding
- Unexplained weight changes
- Excessive hair growth or hair loss
- Persistent fatigue
- Heat intolerance or heart palpitations
- Severe one-sided pelvic pain alongside a missed period, which requires urgent assessment to rule out an ectopic pregnancy

“Missed periods are common and usually explainable,” says Dr Koh. “But they’re also your body’s way of flagging that something is worth investigating.”