How foods for your cycle work

1. What it shows

Foods for your cycle are part of FemNote Premium. They suggest everyday foods for the day of your cycle, in three places:

• Today: 3 foods for today, each with one reason, and one habit, such as having tea and coffee between meals rather than with them.
• The guide: what your body is doing in this part of your cycle, the 3 foods, more foods for these days, and the sources.
• Cook tonight: when two ideas use your fridge equally well, the one with a food for today comes first, with a label such as Lentils, a source of iron.

The foods are ordinary foods from the supermarket, such as lentils, broccoli, yoghurt or salmon. There are no supplements, calories, portion sizes or diets.

Suggestions depend only on where you are in your cycle and on the day. They never depend on your check-ins, symptoms or patterns. They leave out what you don't eat (you choose this under What you eat), the foods on your watch list and the food of an experiment you are running.

2. How a day becomes a moment

Your phone works out where you are in your cycle from the periods you log, with the same phases as the rest of the app: your period, then the follicular phase, the 3 days around the estimated ovulation, and the luteal phase, which is the last 12 days before your next period. The phases are scaled to your own cycle length.

Each day belongs to one moment:

• Early period: the first 2 days of your period.
• Later period: the rest of your period, until you log that it has ended.
• Follicular: after your period, until the days around ovulation.
• Ovulation: the 3 days when ovulation is estimated. With hormonal birth control, this moment is never shown.
• Luteal: the luteal days before the last 5.
• Before your period: the last 5 days before your next period is expected.
• Bleed: with hormonal birth control, the days of your bleed. We say bleed and use cycle days instead of phase names, because hormonal birth control changes the phases.
• Everyday: when your period is late, when you have no periods, when we don't know enough about your cycle yet (an irregular cycle shows phases after 3 logged cycles), and on the days between bleeds with hormonal birth control.

An example: in a 28-day cycle with a 5-day period, days 1 and 2 are early period, 3 to 5 later period, 6 to 13 follicular, 14 to 16 ovulation, 17 to 23 luteal and 24 to 28 before your period.

These are estimates. Real cycles vary, most of all in the days before ovulation (Bull and others, 2019). Estimates only. Not a method of contraception.

3. How we choose the foods

Each moment leads with a few nutrients, chosen from what the body is doing then and from the advice of health bodies:

• During your period or a bleed: iron, because iron is lost with the blood, and vitamin C, because vitamin C increases iron absorption. Heavy periods are a very common cause of iron deficiency anaemia (NHS).
• Follicular days: iron again, because iron stores build up over weeks, not days, with folate and vitamin C.
• Ovulation and luteal days: folate, calcium, vitamin B6 and magnesium.
• Before your period: calcium, magnesium and vitamin B6. Appetite and how much we eat tend to rise a little before a period (Tucker and others, 2025), so the habit for these days is smaller meals more often (NHS).
• Everyday: iron, calcium and folate.

A food is named for a nutrient only when it is a source of it, as EU food law defines it: 100 grams of the food, as you eat it, give at least 15% of the nutrient reference value (for a drink, 100 ml give at least 7.5%). The values per 100 grams come from USDA FoodData Central, a public database of food composition.

We also leave a nutrient out when the body absorbs little of it from that food (spinach is not named for calcium), or when the US value comes from additives that bread in Europe may not have (bread is not named for calcium).

Each reason is a plain fact about the body, or the health claim that EU law authorises for that nutrient, word for word (Commission Regulation (EU) No 432/2012). These are the sentences we use:

• Iron contributes to normal formation of red blood cells and haemoglobin.
• Vitamin C increases iron absorption.
• Calcium contributes to normal muscle function.
• Magnesium contributes to a reduction of tiredness and fatigue.
• Vitamin B6 contributes to normal red blood cell formation.
• Folate contributes to normal blood formation.
• Vitamin B12 contributes to the reduction of tiredness and fatigue.
• Vitamin D contributes to the maintenance of normal muscle function.

We never use the authorised claims about zinc and fertility or about vitamin B6 and hormonal activity: FemNote never says that a food changes your phase, your hormones or ovulation.

Each day, your phone picks 3 foods from different food groups. The same day always gives the same foods, and they change from day to day. If what you eat and your watch list leave too few foods, you see fewer than 3 rather than a repeat.

In Cook tonight, an idea fits today when one serving has a main ingredient that gives at least 15% of the reference value of the moment's first nutrient. Using what is in your fridge and needing fewer extra ingredients still come first, and the recipes themselves never name a phase.

4. What it is not

These are suggestions of ordinary foods. They are not personal medical or nutrition advice, a treatment or a diet, and we never say that a food eases, relieves or prevents a symptom.

No food has been shown to change the phases of your cycle. Popular ideas such as seed cycling, eating certain seeds in certain phases, have no evidence for their timing (Nagarajan and others, 2025). Supplements tested for period pain have no high-quality evidence either (Pattanittum and others, 2016).

FemNote is a wellness app, not a medical device. It doesn't diagnose, treat or prevent any condition.

If your periods are heavy, or you often feel very tired or short of breath, talk to your doctor. Heavy periods are a common cause of iron deficiency anaemia, and food alone does not treat anaemia (NHS). If you are pregnant, have a condition or have questions about what you eat, talk to your doctor or a dietitian.

5. Your data stays on your phone

Your phone chooses your foods. Your cycle day, your phase and your answer to What do you eat? are stored only in FemNote's encrypted database on your iPhone. They are never sent to our servers, and never part of app statistics, crash reports, emails or notifications.

When Cook tonight asks our server for more recipe ideas, it sends only the foods in your fridge, as our privacy policy explains. Your phase and what you eat are not sent: your phone filters and ranks the ideas itself.

The foods, their values and the sentences come with the app.

6. Brands can't pay

The suggestions are generic foods, not products or brands. No brand can pay to have a food suggested, to change its place or its wording. We earn from subscriptions.

FemNote has no ads. If we ever show a sponsored product, it will be clearly labelled Ad, and it will never change which foods you see.

7. Version and changes

This is version 1 of the method, from 19 October 2026. A dietitian will review the foods, their values and every sentence.

We announce every change to the moments, nutrients, foods, thresholds or wording on this page, with the new version number, the date and what changed.

Think a food or a reason is wrong? Tell us through the support page. A real person replies within 2 working days.

8. Sources

• Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods, and the EU Register of nutrition and health claims.
• Regulation (EU) No 1169/2011 on food information to consumers, Article 7(3) and Annex XIII (nutrient reference values and significant amounts).
• Regulation (EC) No 1924/2006 on nutrition and health claims made on foods, Annex (the claim source of).
• U.S. Department of Agriculture, Agricultural Research Service. FoodData Central. Public domain (CC0 1.0).
• EFSA Panel on Dietetic Products, Nutrition and Allergies (2015). Scientific Opinion on Dietary Reference Values for iron. EFSA Journal 13(10), 4254.
• NHS. Iron deficiency anaemia and PMS (premenstrual syndrome).
• Tucker JAL, McCarthy SF, Bornath DPD and others (2025). The effect of the menstrual cycle on energy intake: a systematic review and meta-analysis. Nutrition Reviews 83(3), e866-e876.
• Bull JR, Rowland SP, Scherwitzl EB and others (2019). Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles. npj Digital Medicine 2, 83.
• Pattanittum P, Kunyanone N, Brown J and others (2016). Dietary supplements for dysmenorrhoea. Cochrane Database of Systematic Reviews, CD002124.
• Nagarajan DR, Mani Jacob D, Munir Mufti M and others (2025). Efficacy of seed cycling as an integrative therapy for premenstrual syndrome and polycystic ovary syndrome in reproductive-aged women: a systematic review. Cureus 17(8), e90997.

Nutrient values in FemNote: U.S. Department of Agriculture, FoodData Central, in the public domain. Claim sentences: the EU Register of nutrition and health claims.