Open Luna

A private period tracker that respects your data

Cycle data is some of the most personal you have. Here's what to look for in a private period tracker β€” and how Luna is built to keep your data yours.

Open Luna in Telegram

89 days Pro free

Side-by-side comparison

FeatureLunadata-hungry apps
In the ad businessNoSome apps yes
Account / email requiredNo β€” uses TelegramOften yes
Install requiredNo β€” runs in TelegramUsually yes
Data you can controlYour entries, your choice to shareVaries
Core tracking priceFreeVaries
Languages17Varies

What to check in a private tracker

Read the privacy policy for two things: does the app share or sell your data to third parties / advertisers, and can you delete your data on request. Be wary of free apps funded by ads β€” your data may be the product.

A cautionary tale

In 2021, Flo settled with the US FTC over allegations it shared users' health data with companies like Facebook and Google. It's a reminder to check how any period app actually handles your data β€” not just what the marketing says.

How Luna approaches privacy

Luna keeps your data tied to your Telegram session, isn't in the advertising business, and shares your cycle with a partner only if you choose to. You should still read our current privacy policy and decide for yourself β€” that's the responsible way to choose any health app.

Honest note

No app is perfectly private, and you should always verify claims against the current privacy policy rather than marketing. Luna's design minimises data and avoids the ad business, but the right choice is the one you've checked yourself.

Frequently asked questions

What's a healthy cycle length?

Cycles between 21 and 35 days are healthy. Average is 28 days. What matters more than the exact number is consistency from month to month.

When should I track my cycle?

Daily, even if you only log the period start date. After 1-2 cycles, Luna's predictions become accurate. Adding mood, symptoms, and cervical mucus makes them sharper.

Is it safe to skip my period using birth control?

Yes, modern continuous birth control regimens are safe and supported by major medical bodies. The withdrawal bleed week was historical convention, not medical necessity.

Can stress mess up my cycle?

Yes. Chronic stress can delay ovulation, lengthen cycles, or stop periods (hypothalamic amenorrhea). Reducing stress + adequate calorie intake usually restores cycles.

How is Luna different from other trackers?

Luna runs entirely inside Telegram β€” no app to download. Predictions adapt to your actual data. Privacy-first: data never sold. Free for the first 89 days, then optional Pro.

When should I see a doctor about my cycle?

Cycles consistently shorter than 21 days or longer than 35, periods longer than 7 days, severe pain that disrupts daily life, bleeding between periods, or no period for 3+ months without pregnancy.

Sources

  1. American College of Obstetricians and Gynecologists. Your menstrual cycle.
  2. Royal College of Obstetricians and Gynaecologists (UK). Painful periods.
  3. NHS UK. Irregular periods β€” causes and when to see a GP.
  4. Harvard Medical School. Women's health publications.

Read more from our guide

Open Luna in Telegram

A cycle tracker that isn't in the ad business and runs in Telegram. 89 days of Pro free.

Open Luna in Telegram

89 days Pro free