Menstrual Phase
Nutrition Guide
Iron, omega-3s, and what the evidence actually shows
Understanding the Menstrual phase
Your period begins when progesterone and oestrogen drop. The uterine lining sheds, prostaglandins trigger cramps, and iron is lost through bleeding. Your body's nutritional needs are at their most specific right now, and most apps completely ignore them.
What your macros should look like in the Menstrual phase
Maintain: around 1.6–1.8g per kg. Protein helps stabilise blood sugar and supports tissue repair.
Moderate. Complex carbs (oats, sweet potato, legumes) help serotonin production and ease mood dips.
Prioritise omega-3s. Fatty fish, flaxseed and walnuts are the main dietary sources of the nutrient most studied for period pain.
What your body needs most right now
Replenishes losses from menstrual bleeding. Particularly important for heavy periods.
Widely discussed for cramping, though the 2016 Cochrane review of supplements for period pain does not cover it. Leafy greens, pumpkin seeds and dark chocolate are the usual food sources.
The nutrient most studied for period pain. Later meta-analyses are positive, though heterogeneity is high and Cochrane rated the underlying evidence low quality. Found in oily fish, flaxseed and walnuts.
Supports immune function and reduces inflammatory markers during menstruation.
Helps regulate mood and reduce PMS symptoms that often carry into day 1–2.
Foods to eat more of
The richest dietary source of long-chain omega-3, the nutrient with the most trial attention for period pain.
Iron + magnesium + vitamin C in one food. The vitamin C boosts iron absorption.
Rich in magnesium and iron. One of the few cravings that's actually useful.
Plant-based iron plus fibre to stabilise blood sugar and ease digestive symptoms.
Reviews of ginger for period pain report lower pain scores, though the trials are small and comparisons with anti-inflammatory drugs are inconclusive.
Curcumin trials used concentrated supplements with piperine; turmeric as a spice is poorly absorbed by comparison.
Complex carbs that raise serotonin gradually: mood support without the sugar crash.
Zinc and magnesium in a convenient snack. Good for cramps and immune support.
Foods to cut back
Worsens inflammation, disrupts sleep, and depletes magnesium.
Spikes prostaglandin production. Makes cramping and mood swings worse.
Constricts blood vessels and can intensify cramps. Consider cutting or switching to matcha.
Causes water retention and worsens bloating.
Working out in the Menstrual phase
Low-to-moderate intensity works best. Walking, yoga, and light strength training are well-tolerated. High-intensity output on days 1–2 is counterproductive for most people, which is the reasoning behind setting a slightly lower calorie target for this phase.
Important: this page summarises published research on nutrition across the menstrual cycle, and says where that research is weak. It is educational content, not medical advice, and Oli is not a medical provider. The app itself tracks calories, protein, carbohydrates, net carbs and fat, with a separate target profile per cycle phase. It does not track the nutrients named above, and it does not track symptoms.