Questions

What is PMDD?

Premenstrual dysphoric disorder is a cyclical mood disorder tied to the luteal phase — the week or two between ovulation and your period. It is in the DSM-5. It affects somewhere around 3–8% of people who menstruate, depending on the study and the population.

The current understanding is that it isn’t a hormone imbalance. Hormone levels in PMDD are typically normal; the difference is how the brain responds to their ordinary rise and fall. That distinction matters, because it’s the reason a blood test can’t find it, and the reason two months of daily records can.

How is it different from PMS?

By severity and by consequence. PMS is uncomfortable. PMDD takes the fortnight — work, relationships, and often the sense of being recognisably yourself. The diagnostic criteria require significant distress or interference with functioning, and at least one severe mood symptom.

There’s also PME — premenstrual exacerbation — where an underlying condition like depression, anxiety, ADHD or bipolar disorder gets sharply worse premenstrually but doesn’t clear up after your period. PME is real and common and treated differently, which is why the timing question matters as much as the severity one.

Is the self-check a diagnosis?

No, and it can’t be. It’s the PSST — the Premenstrual Symptoms Screening Tool, published by Steiner, Macdougall and Brown in 2003 — reproduced as written, and scored by its own published rule.

A screening tool tells you whether something is worth investigating. A diagnosis of PMDD requires a clinician, and a minimum of two cycles of daily prospective ratings. There is no shortcut, and anything that offers you one is selling something.

What is the DRSP?

The Daily Record of Severity of Problems: the standard daily form used to confirm a premenstrual disorder. You rate a set of symptoms on a 1–6 scale, once a day, every day, for two full cycles. Recorded on the day, not remembered afterwards — that’s the whole point of it. The pattern it produces, symptoms climbing across the luteal phase and dropping when bleeding starts, is what a diagnosis is actually built on.

Nothing I typed was sent anywhere. Really?

Really. The self-check runs entirely in your browser, and the result is worked out there. You don’t have to take our word for it: open your browser’s developer tools, watch the Network tab, and take the whole thing. Nothing goes out. The privacy page explains how to check the rest.

Why is the app iPhone-only?

Because one person is building it, and building one platform properly beats building two badly. Native iOS also gives access to HealthKit, proper notification timing for the luteal warning, and on-device processing for anything sensitive.

Android is wanted and not promised. If you’d use it, say so on the waitlist — that’s genuinely how the decision gets made.

What does the app cost?

The daily logging, cycle tracking and basic graphs are free and stay free. Prediction, the full DRSP export and the coaching features are a subscription. Pricing is localised, including for India.

No trial that bills you silently. No cancellation maze. If the app isn’t helping you, it should be easy to leave, and it will be.

Do I need an account?

No. The app is local-first and works with no account at all. Sign in with Apple exists only if you want encrypted sync across your devices, and that syncs into your own private iCloud database rather than to us.

Can my partner see it?

Only if you set that up, and only what you choose to share — a heads-up about the coming luteal window without the underlying detail, if that’s what you want. It’s off by default and revocable. There’s more for them on the partners page.

I took the self-check and it said nothing much. I still feel like something’s wrong.

Then something is probably wrong. The PSST is deliberately strict, it’s answered from memory, and your answers depend heavily on where in your cycle you took it. One month is not a pattern.

Start writing the days down. Two cycles of daily notes will show something a four-minute screener can’t — and if it turns out not to be premenstrual at all, that’s worth knowing too.

Who made this, and why should I trust it?

One product designer, working alone. The reasoning is set out honestly in the manifesto, including what they are not. Every clinical claim on this site is sourced and cited on the page where it appears, so you can check it rather than trust it.

I’m struggling right now.

Free, confidential numbers are here, for India, the US, the UK and Ireland, and everywhere else.