TikTok influencers promote cycle syncing, but where’s the evidence?

By Hugo Francisco de SouzaReviewed by Susha Cheriyedath, M.Sc.Mar 18 2025

Is your TikTok health advice legit? A new study reveals that most cycle-syncing content lacks scientific backing—don’t let viral trends shape your well-being!

Study: Sync or Swim: Navigating the Tides of Menstrual Cycle Messaging on TikTok. Image Credit: Krotnakro / Shutterstock

In a recent study published in the journal Perspectives on Sexual and Reproductive Health, researchers in the United States attempt to understand the views and knowledge shared by content creators on the social media platform TikTok. Specifically, they examine content creators' credentials, citations of scientific sources, messages and recommendations, and perceived benefits of individuals consuming such content.

Study Findings

Study findings revealed that while influencers and wellness coaches popularize menstrual cycle syncing as a means to enhance physical well-being and performance, very few (~30%) provide their credentials (expertise) while doing so, and far fewer (4%) cite scientific sources for their information.

Alarmingly, even those who cited scientific sources often did so in vague, unspecified fashions without providing publication titles, publication years, or authors. The study highlights that much of the content is anecdotal rather than scientifically validated, raising concerns about the accuracy of health claims.

Background

Menstrual ‘cycle syncing’ is the practice of adjusting one’s daily routines to align with the four menstrual cycle phases – menstrual, follicular, ovulatory, and luteal. It is an increasingly popular practice promoted on social media platforms such as Instagram and TikTok, and its supposed benefits include enhanced reproductive, mental, and physical well-being outcomes. Notably, on TikTok alone, more than 285 million views have been garnered for content carrying the hashtag #cyclesyncing.

While TikTok promotes four distinct phases, most scientific studies focus on two broad hormonal phases—follicular and luteal—when analyzing the menstrual cycle's effects on health and performance.

Unfortunately, scientific knowledge on the topic remains insufficient to validate most of cycle syncing’s benefits conclusively. Existing research has not reached a consensus on how menstrual cycle phases affect exercise performance and dietary needs, with many studies yielding mixed results.

Given the diet and exercise alterations promoted by TikTok content creators, understanding the credentials and scientific material they use to back their claims would allow their viewers to make informed choices about the necessity and benefits that these routines may provide them.

“Social media platforms like TikTok can amplify oversimplified and potentially misleading information on cycle syncing. Video content may present exaggerated benefits and claims not strongly supported by scientific evidence, potentially leading to misconceptions and misguided reproductive health practices.”

About the Study

The study evaluated cycle-syncing content on TikTok, focusing on four key aspects: content creator credentials, the use of scientific citations versus anecdotal claims, how cycle syncing is framed and promoted, and the benefits associated with it.

Researchers created a new TikTok account (set to a 22-year-old United States user) and downloaded the top 100 ranked videos related to cycle syncing for analysis. These videos were selected based on ranking and hashtags. To analyze the content, researchers categorized the data into two main groups: cycle-syncing content and creator information.

The first category examined how cycle syncing was discussed, including recommendations related to exercise, diet, and benefits, while the second focused on whether creators provided their credentials or cited scientific research.

To ensure accuracy, Gwet’s agreement coefficient (≥ 0.70) was used to train and assess coders' performance.

Study Findings

Summary statistics of the 100 videos downloaded revealed that they averaged 45,235.50 likes and were a mean of 1:07 min long (range = 0:06-1:52 min).

Creator credentials analysis revealed an alarming trend – only 30% of content creators (n = 30) using the hashtag #cyclesyncing provided their credentials. These included a mix of health coaches, clinicians, and fitness instructors.

Even more concerning, only 4% of content creators (n = 4) mentioned scientific research as the source of their beliefs or recommendations. When scientific research was referenced, it was often described in vague terms, such as 'studies show,' without providing publication details.

The study also identified patterns in the types of recommendations given.

57% and 54% of content creators recommended cycle-syncing exercises and diets, respectively. Exercise recommendations frequently included walking and yoga throughout the cycle, while higher-intensity activities such as cardio were most commonly suggested for the ovulatory phase and weightlifting for the luteal phase.

Dietary recommendations were less specific but included general mentions of magnesium, iron, and omega-3 consumption.

Overall, the top 100 videos promoted 15 total benefits of cycle syncing, with balancing hormones (11%), improving acne (10%), and reduced menstrual symptoms such as cramps (9%) being the most common.

However, 63% of videos promoted cycle syncing without citing any specific benefits.

Some creators framed hormonal contraceptives as harmful, reflecting broader 'hormonophobia' trends on social media.

Conclusions

The present study suggests a substantial lack of credibility among TikTok content creators promoting cycle syncing, with much of the content being anecdotal rather than scientifically validated.

Furthermore, TikTok’s content generally does not aim to tailor diet and exercise recommendations to individuals; instead, it suggests that the same approach should apply to all female viewers.

Given that the majority of viewers were identified in the 18-24 age group, the study suggests that future research should investigate how TikTok’s cycle-syncing content influences young viewers’ perceptions of reproductive health and whether it affects their decisions on contraception and wellness routines.

Additionally, while cycle syncing is sometimes framed as a method to “rebalance hormones” after discontinuing hormonal contraceptives, further research is needed to determine whether cycle syncing content actively discourages hormonal contraceptive use or simply reflects broader discussions about alternatives to synthetic hormones.

Since TikTok's algorithm prioritizes engagement-driven content, videos promoting cycle syncing without scientific references may still gain significant visibility, influencing user exposure to anecdotal health claims.

The researchers acknowledge that their sample of 100 videos may not fully represent all cycle syncing content on TikTok, as individual users receive personalized content recommendations based on algorithmic factors.

Furthermore, the study analyzed content rather than its actual influence on viewer behavior, highlighting the need for future studies on audience impact.