Does TikTok Know I'm Ovulating?! A Content 'Cycle' You Didn't Sign Up For

One week it's wellness content and creatine bulk-buys. The next it's rage bait and comment section fights. Then all of a sudden it’s thirst traps and glam ‘GRWM’ reels. Then, like clockwork, a CYCLE, if you will…it repeats.

I’ll be honest, that’s my feed. I started to notice that when I was in my luteal week each month, TikTok would serve me up pure, unadulterated emotional damage. Soldiers coming home surprising their kids, dogs reunited with their long lost owners and questions about why I’m so ugly right now.

I scrolled and for 5 days each month, I was a mess.

But this type of content wasn't coming for my tears all throughout the whole month. Only for a few days.

SUS.

When I noticed this correlation, my instinct was to laugh it off as another "is my phone listening to me" conspiracy.

Here’s the big bloated ‘however’ though. 

When you actually dig into what social media platforms track, how their algorithms work, and what's already been proven about cycle-based targeting, the honest answer is that paranoia is probably my friend on this one.

So, despite being prostrate in a nest of blankets, chocolate and hot water bottles like a stereotypical caricature of a pre-menstrual woman, I followed my paranoia.

I Got Receipts!

Seven years ago, the Wall Street Journal found something. Popular apps were sending Facebook deeply personal signals within seconds of being recorded. Heart rate, home searches and where a woman was in her menstrual cycle!

One of them was Flo, a period tracker with over 16 million downloads a year. Flo told Facebook whether a user was on an ordinary day, her period, ovulating, or pregnant, tagged with an ad identifier that could be matched straight back to her Facebook profile.

Nobody at Facebook needed to ask for this. It arrived through the SDK, folded into ordinary app analytics, without users understanding what "personalised ads" actually meant.

Read that again: this happened at Facebook scale, with WSJ's reporting and a New York State investigation to prove it, years ago. The tech has only gotten sharper since. *Cough cough* AI *cough cough*...

The algorithm doesn't need to know what’s going on in your bathing suit area. It just needs to know your predictable patterns.

The Federal Trade Commission found that Flo disclosed sensitive health data, including when users were on their period or trying to conceive, to Facebook's and Google's analytics divisions, plus several other third parties, despite explicitly telling users that information would stay private. Flo didn't stop until a Wall Street Journal investigation forced its hand.

Flo, along with Google and Flurry, has since paid out $59.5 million combined in related class actions. Meta was found liable by a jury before settling on the eve of the verdict. None of the companies admitted wrongdoing.

Yikes. An app built entirely on trust, designed to hold the most intimate calendar a menstruating person keeps, was feeding "app events" like pregnancy status to ad ecosystems that build the profiles serving your feed. That means that that kind of intimate user data has immense power when applied to social media algorithms and advertising strategies.

The Menstrual Content Cycle

Here's the part that should actually reframe how advertisers and creatives think about targeting. Platforms like TikTok build entire recommendation systems around one job: detect the smallest shift in your behaviour and react to it, in real time.

Watch time, rewatches, saves, shares, what you screenshot, how long you hover before scrolling past that content you never searched for about boobs jobs in Turkey or sad puppy adoption. None of that actually requires a single direct data point about if you’re riding the crimson wave or howling at the full moon like a feral cat.

If your engagement with a certain content "flavour" (softer, more introspective, more retail-therapy-coded, whatever your pattern is) rises and falls on something close to a rhythm, the algorithm (pun intended) will find that pattern. It doesn't file it under "menstrual cycle." It files it under "this WORKS at THIS point, do MORE of it." The systems don't need a name for what it's exploiting. It just needs the data.

So no, there's nothing confirmed that TikTok records menstrual cycle or fertility data directly. No "ovulation detected, serve reels of men saying your name as they do push ups." (Don’t JUDGE me!) But the infrastructure that would produce that exact outcome already exists and is already running. So…is it bad?

With great power…

I used to be someone who thought, so they’re collecting data about me to serve me up more relevant content…what’s so bloody wrong with that?

Turns out I feel differently about that when it actually comes to something bloody. Because of the 4 evils…

1. Privacy

Menstrual and fertility data is about as sensitive as personal data gets, especially post-Roe in markets where reproductive information carries legal risk, not just embarrassment. The Flo case shows this data has already leaked into ad ecosystems that were never meant to have it.

2. Misinformation

Fertility and cycle content is a genuinely huge, under-regulated corner of TikTok and Instagram. Algorithmic amplification doesn't check medical accuracy, it checks engagement.

If cycle-adjacent content performs best during someone's most emotionally or hormonally sensitive window, that's exactly when the least-vetted advice is most likely to land. Best case, a sad puppy gets adopted. Worst case, the outcomes are genuinely harmful. And that's not me claiming people who menstruate are emotional idiots. It's about a system taking advantage of a predictable window purely because it's profitable, without ever having to face the consequences of what it amplifies. Hence, evil.

3. Addiction by design

If a platform can detect when you're more susceptible to certain content or spending triggers, it also knows exactly when to serve more of it. That's not a hypothetical dark pattern, it's the same mechanism Facebook already proved works on ad conversion, applied to attention instead of purchase. It's nothing new. We all know these platforms are built to hold attention as long as possible.

Worth being precise about what "evil" actually means here though. There's a real difference between advertising that understands its audience and creative that's timed to work because someone is momentarily more vulnerable. The first is the job. The second is what this piece is actually about. If your industry radar is pinging "but isn't targeting the whole business we're in", that's exactly the distinction worth sitting with, and exactly why we think this deserves scrutiny from people who make the ads, not just people who study the platforms.

4. Manipulation of self-perception

Beauty, wellness and "fix yourself" content hitting on a predictable monthly rhythm shapes how women in particular see their own bodies and moods, often reframing normal hormonal fluctuation as something to buy your way out of. I just saw a BBC interview with Dr Helen O’Neil of Hertility fame talking about the ‘luteal uglies’. I rage-vomited all over my phone that ‘luteal uglies’ are A Thing.

To be as helpful as possible, I’ve created a handy 4 Evils checklist which you can download here for gratis. It covers The Evils in prettier detail.

What this means if you build brands, campaigns or content

You don't need a tinfoil hat to take this seriously (you can borrow mine), and you don't need to overclaim what isn't proven either. What you need is to build your campaigns with open eyes.

• Get curious about your own targeting logic. If you're running highly granular retargeting or lookalike audiences on female-skewing products, it's worth asking your media team what behavioural signals are actually feeding those models, and whether cyclical patterns could be an unintended input. Most teams haven't asked because nobody's told them to. That's the gap, not a gotcha.

• Think about timing ethics, not just timing performance. "When is she most likely to buy" and "when are they least resistant" can be the same insight wearing different clothes. Knowing which one you're using is a genuinely useful creative discipline, not just a compliance exercise.

• Back your fertility, beauty and wellness content with real sourcing. If the algorithm is already amplifying this category regardless of accuracy, the brands and creators who show their work will stand out and build actual trust, not just reach.

• Say the quiet part out loud in your own marketing. This is the one that actually matters most. Audiences are getting sharper about this exact conversation, fast. A brand willing to be upfront about how targeting works, what it knows, what it doesn't, and where it draws the line, earns more credibility in a single line of copy than most category advertising manages in a full campaign. That transparency isn't a limitation on effective marketing. Right now, it's one of the only genuine differentiators left.

To Conclude

The platforms don’t know if I’m ovulating. They don't need to. Because they read behaviour, and for a huge chunk of people with menstrual cycles, behaviour and biology move in step often enough that algorithms don’t need to tell the difference. Neither should we pretend it can't. But we should consider our responsibility as marketers, communicators, creators and advertisers when we utilise the behaviour of algorithms for commercial gain.

When we put campaigns together we should ask what our message is and who is it for? How will they feel if they see it? Are we clogging up feeds with crap? How are we standing out and is it ethical?

Messages that could cause damage to the culture and society we live in, which already penalises and punishes people who have menstruating or post-menstruating bodies, should bear in mind how they could land and reflect on the brand based on knowledge of how algorithms exploit behaviour patterns.

Now. Back to my sad puppy adoption papers…

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