What are the effects of drinking instant coffee during menstruation?
Jun 30, 2025
Source: Cainiu Health
Dr. Zhang Lu
Introduction
In general, drinking instant coffee during menstruation may exacerbate menstrual discomfort, affect iron absorption, disrupt endocrine balance, worsen water and sodium retention and edema, and stimulate gastrointestinal function. During menstruation, small amounts of plain black coffee without additives may be consumed, but it should not be taken on an empty stomach, and it is important to consume it with iron-rich foods such as lean meat and spinach.
Generally, drinking instant coffee during menstruation may cause various effects on the body, including worsening menstrual discomfort, interfering with iron absorption, disrupting endocrine balance, aggravating water-sodium retention and edema, and stimulating gastrointestinal function. A detailed analysis is as follows:
1. Worsening Menstrual Discomfort
Instant coffee contains caffeine, which can stimulate uterine smooth muscle contractions, potentially exacerbating dysmenorrhea or sensations of lower abdominal pressure. Additionally, caffeine stimulates the central nervous system, possibly causing premenstrual anxiety, insomnia, or mood swings in some individuals, further increasing physical fatigue.
2. Interfering with Iron Absorption
Women need to replenish iron due to blood loss during menstruation. However, tannic acid and caffeine in instant coffee can bind with dietary iron ions, forming complexes that are difficult to absorb, thereby reducing iron absorption rates (by approximately 30%). Frequent consumption of instant coffee during menstruation over a prolonged period may increase the risk of iron-deficiency anemia, especially in women with heavy menstrual flow.
3. Disrupting Endocrine Balance
Caffeine can affect estrogen metabolism, leading to fluctuations in estrogen levels. Consuming more than 300 mg of caffeine daily during menstruation may prolong the luteal phase or alter the ovulation cycle, potentially causing menstrual irregularities such as abnormal menstrual flow or cycle disturbances in some individuals.
4. Aggravating Water-Sodium Retention and Edema
Caffeine in instant coffee has a diuretic effect but may also promote adrenaline secretion, causing vasoconstriction and increased renal sodium reabsorption, thereby worsening water-sodium retention. Women who are prone to eyelid or lower limb edema during menstruation may experience more pronounced swelling after consuming instant coffee.
5. Stimulating Gastrointestinal Function
During menstruation, gastrointestinal motility naturally slows in women. Caffeine stimulates gastric acid secretion, which may cause bloating, stomach pain, or indigestion. If the instant coffee contains sugar or non-dairy creamer, such as trans fatty acids, it may further burden the gastrointestinal tract. Symptoms are particularly noticeable when consumed on an empty stomach.
Women may consume small amounts of plain black coffee without additives during menstruation, but should avoid drinking it on an empty stomach and ensure it is consumed with iron-rich foods such as lean meat and spinach. Those experiencing dysmenorrhea, anemia, or gastrointestinal sensitivity should avoid coffee altogether and opt for warm beverages such as brown sugar water or ginger tea, which are more beneficial for menstrual health.
