How much protein is in period blood?

Period blood is made up of blood, uterine lining tissue, mucus, and vaginal secretions. While it contains many of the same components as regular blood, its protein content is relatively low compared to the total protein you consume in your diet.

Protein in Period Blood

• Blood itself contains proteins such as hemoglobin, albumin, and clotting factors.

• Hemoglobin, found in red blood cells, is a protein responsible for carrying oxygen.

• On average, menstrual blood contains approximately 0.5–1.5 grams of protein per 100 milliliters of blood, depending on the flow and amount of tissue in the sample.

For context, the average period may result in 30–80 milliliters of blood loss, which is equivalent to roughly 0.15–1.2 grams of protein per cycle — a very small fraction of your daily protein needs.

Key Takeaways

1. Minimal nutritional impact

   • While menstrual blood contains protein, the amount lost is not significant enough to affect daily dietary requirements in most healthy individuals.

2. Iron and blood loss are more important

   • Menstrual blood loss can impact iron levels, which is why iron-rich foods or supplements are recommended, especially for heavy periods.

3. Focus on balanced nutrition

   • Protein intake should come from food, not period blood replacement. Include a variety of protein sources in your diet to maintain energy and hormone balance.

Bottom Line

Menstrual blood contains some protein, mostly in the form of hemoglobin and clotting proteins, but the amount lost during a period is very small. Ensuring adequate dietary protein is what truly supports energy levels, hormone production, and menstrual health — not the tiny protein lost through bleeding.