Research published in 2022, conducted in 2010, showed that women's menstrual cycles were synchronized with the moon until 2010.

Posted by The Charlie Kirk Show, Aug 5, 2026Checked Nov 2, 2026

Polygraph verdictMixed

Sources: 4 contradict2 context
Said: 1 time·
Confidence: 60%

The Charlie Kirk ShowAug 5, 2026

The sources support the core claim that women's menstrual cycles were synchronized with the Moon before 2010 and that this weakened after LED and smartphone use, but they contradict the claim's dating: the study was published in Science Advances on 2025-09-24, not in 2022, and it analyzed long-term menstrual records rather than being conducted in 2010.

A detail. The sources confirm the gist; the verdict faults a detail such as a date, number or wording.

A guest makes this claim. Listeners heard it, so it counts against the post, and on the guest's own record.

What was said

… So if you're not making these hormones, especially in the morning, you're going to deal with fertility issues. And then we have the issue at night. It was women used to actually cycle with the moon. We have some really interesting data that came out in around 2010 that showed women stopped cycling. Actually, that the research came out in 2022. It was done in 2010. That showed women cycled with the moon up until that time. What happened in 2010? We all got smartphones, and so women fell out of sync. Their menstrual cycles became irregular in 2010 because of this artificial light at night issue that we all have now. So, wait, wait, wait, wait, hold on. …

The Charlie Kirk Show · Aug 5, 2026· from the transcriptPost →

What we found

Contradicts. The study was published on 2025-09-24 in Science Advances, which contradicts the claim that the research was published in 2022.[2][3][4]

Contradicts. The study analyzed long-term menstrual records of women spanning roughly the past century and past 24 years, rather than being conducted in 2010 as the claim states; 2010 is the cutoff date for the records' change in synchronization, not the study's date.[2][5]

Supports. The primary study reports that menstrual cycles recorded before the introduction of LEDs in 2010 and widespread smartphone use were significantly synchronized with the Moon, supporting the central assertion of synchronization until 2010.[2][3]

Context. Post-2010 records coupled to the Moon mostly in January, during perihelion and minor lunar standstills, so synchronization weakened rather than ending entirely.[2][3][6]

Context. Sources note the lunar influence on menstrual cycles remains controversial, and an older 2017 Snopes review called menstrual synchrony research into question.[1][4]