Iron on this plate
4.2 mg
Heme1.6 mg
Plant2.6 mg
Plate check
Photograph a meal and see the iron on it, plus what on the plate helps or blocks absorption.
Cycle and iron tracking
Put the Fe back in female.
Fe is iron. Every period costs some. Ferritin keeps count.
The period tracker that counts iron. Log your cycle, see what each period costs in iron, and keep your ferritin results on the same timeline.
You are on the list. We will write when Ferritin opens.
Early access for iPhone and Android.
9:41
Cycle day 5 · Period
Today
1
2
3
4
5
Iron this period
0mg
Estimate, not a lab result
Iron stores
Ferritin31µg/L
Goal 50Rising since June
Next
13:00Lunch: lentils and peppers
22:00Iron at bedtime
TodayLabsLogLearnMe
Living with low iron
You sleep eight hours and wake up tired.
The stairs feel steeper than they used to.
There is more hair in the brush.
You are cold when everyone else is fine.
You lose words halfway through a sentence.
And you have been told it is stress.
It might be iron.
Iron carries oxygen to every cell, and oxygen is how your cells make energy. When your stores run low, nothing fails all at once. You fade slowly, and it is easy to blame everything else: work, sleep, age, your own willpower.
What low iron can feel like
Tired all the time
Not sleepy, drained. A full night of sleep and you still start the day on empty.
Brain fog
Rereading the same line, losing words, a head that feels full of cotton.
Breathless on stairs
Your heart racing on a climb that used to be nothing.
Hair shedding
More hair in the shower and the brush, and nails that split.
Always cold
Cold hands and feet in a warm room, when nobody else is.
Low mood, short fuse
Less patience and less joy, with no reason you can point to.
Workouts that stall
Heavy legs, slow recovery, progress that stops.
Restless legs at night
An urge to move your legs just as you try to fall asleep.
These signs have other causes too. They are a reason to ask for a blood test, not a diagnosis.
It costs more than energy.
- At work
Focus that runs out by mid-afternoon.
- In your body
Training that stops paying off.
- At home
Less patience with the people you love.
- In your week
Evenings and weekends spent recovering.
Close to1 in 3
women aged 15 to 49 has anaemia worldwide. Iron deficiency is its most common cause, and it starts long before anaemia does: haemoglobin is the last number to fall.
It is not in your head.
It might be in your blood.
A ferritin test shows your iron stores. ferritin.ai keeps the result, counts what each period costs and helps you rebuild.
A typical period takes about
15mg
of iron with it. A heavy one, twice that or more.
Most of the body's iron is in the blood, so every period takes some with it.
Low iron builds up quietly over years and usually turns up in a blood test taken for tiredness.
- mg0115A typical period
- mg0230+A heavy period
- mg031–2Absorbed from food a day
Textbook averages. Your own figure depends on your flow, and Ferritin labels it as an estimate.
How it works
Track the bleed.
Rebuild the iron.
Most cycle apps stop at predicting the next date. Ferritin answers the question underneath it: is my cycle running my iron down?
It counts the iron.
Log your period the way you already do. Every logged period gets an iron estimate, so a heavy month becomes a number.
- Flow by day, from spotting to heavy
- An iron estimate for every period
- Labelled as an estimate, because it is one
It tracks the refill.
Food and supplements are logged against the loss, so you can see whether a month was covered.
- Plate check for iron meals
- Supplements logged as you take them
- Coffee and tea timed around your iron
It keeps the lab results in view.
Ferritin and haemoglobin sit on the cycle timeline, so a recheck is a date in the calendar and not something remembered at the next bout of tiredness.
- Read from a photo or PDF of your report
- Your ferritin trend against your goal
- A recheck date on the calendar
The 28 days
Lose it monthly.
Rebuild it daily.
The app
Where your iron stands,
every day.
Real screens from the app, with demo data. Today shows your iron stores against your goal and plans the day around them: iron meals, coffee timed to stay out of the way, iron at bedtime. Labs keeps every result on one line, with the trend toward your goal and the date to recheck.
Inside the app
Everything that moves your iron,
in one place.
Coffee 10:00Iron 12:002 h apart
Coffee and tea, timed
Keep your coffee. ferritin.ai moves your iron around it, so the two stop meeting.
31 µg/L
Lab reports, read for you
A photo or PDF of your report becomes numbers on your timeline, each with its date and the unit your lab uses.
- Tea with meals
- CRP raised
- Doses missed
Why is it stuck?
When ferritin stops rising, a short check looks at timing, tea, inflammation and absorption, then lists questions for your doctor.
Periods
Supplements
Labs
Doctor pack
Your periods, labs and supplements on one page, ready to share before an appointment.
Label read
Supplement label scan
Scan the label and log the dose your doctor gave you. Ferritin never sets one.
Honest numbers
The number first.
Then its limit.
- 01
An estimate, and it says so.
The iron figure comes from the flow you log. The screen says it is an estimate, right beside the number.
- 02
No diagnosis.
A blood test does that. ferritin.ai keeps the result, explains it in plain words and tells you when it is worth asking your doctor.
- 03
Your dose comes from your doctor.
Ferritin logs what you take and helps you time it. It never tells you how much to take.
mgFe · 26
16
Iron this period
Five days, heaviest on day two.
The Iron Guide
Not ready for an app?
Start with the guide.
Everything Ferritin is built on, in one illustrated PDF: how iron moves, which numbers matter, what to eat and when, how supplements are used well, and what to check when your iron stores will not move.
- 73 illustrated pages in 9 parts
- A 7-day ferritin menu with 21 recipes
- Printable lab tracker, period log and appointment sheet
US$9.99 · PDF · 73 pages · in English · yours to keep
What is ferritin.ai?
A period tracker that counts iron. It logs your cycle, estimates the iron each period costs, tracks the food and supplements that replace it, and keeps your ferritin results on the same timeline.
What does low iron feel like?
Often like tiredness that sleep does not fix, brain fog, breathlessness on stairs, hair shedding, cold hands and feet, low mood or restless legs at night. These signs have other causes too, so they are a reason to ask for a blood test, not a diagnosis. A ferritin test shows your iron stores.
Why track iron alongside my period?
Most of the body's iron is in the blood, so every period takes some with it: around 15 mg in a typical month, twice that or more in a heavy one. Low iron builds up quietly over years. With the loss and the refill side by side, the trend shows before you feel it.
Is the iron figure measured?
No. It is an estimate from the flow you log, and the app says so beside the number. Only a blood test measures your iron.
What is ferritin?
Ferritin is the protein that stores iron. A ferritin blood test is the usual way to check your iron stores. ferritin.ai keeps every result on your timeline, with the date and the unit your lab uses: µg/L and ng/mL are the same number.
Does ferritin.ai diagnose iron deficiency or anaemia?
No. A blood test and a clinician do that. ferritin.ai explains your numbers in plain words, keeps them in one place and tells you when a result is worth taking to your doctor.
Will ferritin.ai tell me how much iron to take?
No. Your dose comes from your doctor or the label you were given. Ferritin logs what you take and helps you time it around coffee, tea and calcium.
When can I use it?
Ferritin is in early access for iPhone and Android. Join the waitlist and we will write when it opens.
Early access
Strong
all month.
Join the waitlist for early access to Ferritin on iPhone and Android.
You are on the list. We will write when Ferritin opens.
Early access for iPhone and Android.