Moon vs other AI: which helps with PMS and PMDD?
General AI like ChatGPT can talk anything through. Moon knows your cycle and your past moments, and is built for the hard PMS moment.
Checked on 13 October 2026 against ChatGPT’s own site and App Store listing.
Feature by feature
How Moon and ChatGPT compare
Every ChatGPT entry is what OpenAI says on its own site, help pages or App Store listing. Where it says nothing, the table says so.
| Feature | Moon in Niyora | ChatGPT |
|---|---|---|
| What it is | A PMS and PMDD support app for the hard moment, with a cycle calendar. | A general-purpose AI assistant from OpenAI. ChatGPT is the example here. |
| Built for | The days before your period, when a feeling hits and you have to decide what to do next. | Any question or task, from writing to research. |
| Help in the hard moment When it’s happening, not after | Built for it Tell Moon what happened. Swipe through other ways to see it, each with its source, calming activities and facts about your body, then decide what to say, with drafts. | In part It can talk a moment through if you explain it. It doesn’t know your cycle or your past hard days unless you tell it. |
| PMS and PMDD | A predicted PMS window, a library of common PMS and PMDD scenarios, your saved moments mapped by cycle day, and a cycle report PDF for a doctor or therapist. | None built in. |
| Cycle prediction | Predicts your period and PMS window from your own logged cycles or your Apple Health period history. | None. |
| AI | Moon runs on Google’s Gemini models. Names and places are replaced on your phone first, and your text isn’t used to train the models. | OpenAI’s models. A setting called Improve the model for everyone controls whether your conversations train OpenAI’s models. |
| Account | None. No sign-up, email or password. | Optional for basic use. Signing in keeps your history across devices. |
| Your data | Entries are encrypted on your phone. Its App Store label lists no data used to track you and none linked to you. | Conversations are kept in your ChatGPT history. Its App Store label lists health, contact info and user content as linked to you. |
| Price | Free to start. Premium is $8.99 a month or $29.99 a year. Lifetime is $79.99 until 30 November 2026. | Free, with paid plans. The US App Store lists ChatGPT Go at $8.00, Plus at $19.99 and Pro from $100. |
| Free version | Moon moments each month, the cycle calendar and PMS window, and calming activities. | Free to use. Paid plans add more use and more features. |
| Platforms | iPhone today. Android coming soon. | iPhone, Android and the web. |
Sources for ChatGPT, checked 13 October 2026: ChatGPT’s App Store listing (US); OpenAI’s help center, Data controls in ChatGPT. Sources for Niyora: its privacy policy and App Store listing.
Who each is for
Who Moon and ChatGPT are for
Moon is for you if
You want help that already knows it’s day 26 and what happened last month, and that ends with something you can do.
ChatGPT is for you if
You want one assistant for everything, and you’re happy to explain your cycle and your situation each time.
The difference
What Moon does that ChatGPT doesn’t
Measured against what ChatGPT describes on its own pages on 13 October 2026.
-
It knows your cycle
Moon knows where you are in your cycle and when your PMS window is, so you don’t have to explain it.
-
It remembers your moments
Moon can point out when the same thought has come round on the same days before, from moments saved on your phone.
-
Every idea shows its source
Each perspective names where it comes from, such as CBT, Stoic philosophy or self-compassion research.
-
Names removed before it sees them
Names and places are replaced on your phone before your text reaches the AI, and your text isn’t used to train it.
Pricing
What Moon and ChatGPT cost
Niyora
Free to start
- Monthly
- $8.99
- Yearly
- $29.99
- Lifetime
- $79.99 until 30 November 2026
Free: Moon moments each month, the cycle calendar and PMS window, and calming activities.
ChatGPT
Free, with paid plans. The US App Store lists ChatGPT Go at $8.00, Plus at $19.99 and Pro from $100.
Free version: Free to use. Paid plans add more use and more features.
Source: US App Store, read 13 October 2026. Prices can differ by country and change with offers.
Niyora prices are in US dollars on the US App Store. Premium adds unlimited Moon moments, your patterns, the cycle report and asking Moon about your past moments.
Privacy
What happens to what you log
What each app declares in its App Store privacy label and its own policy. Each line is the company’s own declaration.
Niyora
- Account
- None. No email, password or sign-in.
- Where entries live
- Encrypted on your phone, with a key that never leaves it.
- Before the AI sees it
- Names and places are replaced on your phone. Your text isn’t used to train the AI.
- Used to track you (App Store label)
- None declared
- Linked to your identity
- None declared
- Collected, not linked to you
- Health, Purchase History, Photos or Videos, Other User Content, Device ID
ChatGPT
- Account
- Optional for basic use. Signing in keeps your history across devices.
- Used to track you (App Store label)
- None declared
- Linked to your identity
- Health & Fitness, Contact Info, User Content, Identifiers, Usage Data, Location, Search History, Diagnostics
App Store label read 13 October 2026.
FAQ
Questions about Moon and ChatGPT
Can I use ChatGPT for PMS?
You can. ChatGPT can talk a hard moment through, but it doesn’t know your cycle or what happened last month unless you tell it each time. Moon, the AI in Niyora, knows where you are in your cycle and your past moments, and every idea it offers names its source.
Does ChatGPT train on what I write?
OpenAI’s help center describes a setting called Improve the model for everyone that controls whether your ChatGPT conversations are used to train its models. Niyora’s text goes to Google’s Gemini models under enterprise terms that bar training on it, after names and places are removed on your phone.
Which AI does Moon use?
Moon runs on Google’s Gemini models through Google Cloud’s Vertex AI, under enterprise terms. Your text isn’t used to train Google’s models and isn’t routinely read by a person. Names and places are replaced on your phone first, and your history stays encrypted on your phone.
How much does Moon cost compared with ChatGPT?
Moon comes with Niyora, which is free to start with Moon moments each month. Premium, at $8.99 a month or $29.99 a year, gives unlimited moments. ChatGPT is free, with paid plans listed on the US App Store from $8.00 for Go and $19.99 for Plus.
How this page was checked
Checked on 13 October 2026. Every ChatGPT fact above comes from these pages, read on that date. We name them here and don’t link to them.
- ChatGPT’s App Store listing (US)
- OpenAI’s help center, Data controls in ChatGPT
Spotted something out of date? neha@niyora.com