Period Bloating Relief: How Adjusting Your Electrolytes Can Help
Period bloating is an all too common symptom that so many women experience before menstruation! If you’ve experienced bloating around the time of your period, it often feels different from the general bloating that you may experience after a heavy meal. For some, you may even notice a fluctuation on the scale or the feeling of clothes fitting tighter.
Hormone Cycle 101
Let’s start off with some quick background on the women’s hormonal cycle. We divide our cycle into 4 phases: the menstrual phase, the follicular phase, the ovulatory phase, and the luteal phase.

From https://www.invitra.com/en/phases-of-the-menstrual-cycle/
The Menstrual Phase
The average cycle, and what is considered “normal,” is about 28-35 days. The first day of the menstrual bleeding marks cycle day 1. During the menstrual phase, hormones estrogen, progesterone, follicle stimulating hormone (FSH), and luteinizing hormone (LH) are collectively the lowest.
The Follicular Phase
During the follicular phase, which lasts about 7-10 days, FSH is the dominant hormone from the brain and estradiol is the dominant hormone coming from the ovaries. FSH signals to the ovaries to release an egg. FSH also triggers follicles within the ovaries to enlarge or swell in preparation for the egg and potential fertilization. These follicles stimulate an increase in estradiol (estrogen), which is critical to help us prepare for ovulation. Progesterone levels are still low throughout the follicular phase.
The Ovulatory Phase
The ovulatory phase begins mid-cycle, and lasts about 3-4 days, although ovulation occurs only when an egg is released. During this time, LH levels spike. This is also called the LH surge, and is stimulated by increased estrogen levels. The LH surge is what triggers the release of an egg, as well as progesterone production.
The Luteal Phase
The hormone cycle finishes with the luteal phase, about 10-14 days. After the LH surge and ovulation, progesterone levels rise. Progesterone is the predominant hormone during the luteal phase. If fertilization does not occur, estrogen levels increase toward the end of the luteal phase to blunt progesterone production. This triggers the start of menstruation and the next menstrual cycle.
Hormonal Influences on Bloating and Water Retention
Estrogen and Progesterone
We have estrogen and progesterone receptors all throughout our bodies. They are even within the tissues that are responsible for fluid balance, like our kidneys and the hypothalamus in the brain. Because of this, they both influence the body systems that control thirst, fluid retention, and sodium regulation.
Sodium loss slightly decreases during the luteal phase, meaning we retain more sodium than in other phases of the cycle. This happens because of both estrogen and progesterone.
Remember that progesterone increases significantly in the luteal phase. Progesterone has a mild diuretic effect, meaning that it causes an increase in fluid loss and urination. Then, estrogen increases around the mid-luteal phase in order to blunt progesterone production and trigger the next menstrual cycle. This rise in estrogen increases sodium retention.
This hormonal switch takes us from a state of losing more fluids and sodium to then retaining more sodium. With increased sodium comes increased water, so it’s common to experience significant bloating during this time just before your period.
Aldosterone and Cortisol
Other hormones like aldosterone are key in regulating water and salt balance. Aldosterone acts within the renin-angiotensin-aldosterone system, or the RAAS. The RAAS is our body’s essential regulator of blood volume, electrolyte balance, and the pressure in our arteries.
Upregulation of the RAAS stimulates sodium retention and the release of antidiuretic hormone (ADH). ADH talks to the kidneys and causes the body to retain more water.
Estrogen is also associated with impacting the hormones involved in the RAAS. Estrogen can indirectly decrease renin levels. Renin is an enzyme produced by the kidneys when blood pressure falls, and begins the cascade of the RAAS. In animal studies, angiotensin (the second “A” in RAAS) was shown to fluctuate with variations in estrogen levels throughout the menstrual cycle.
Vasodilation, or opening of blood vessels, increases toward the end of both the follicular and the luteal phases given the increase in estrogen. This downregulation of the RAAS also causes us to lose more sodium. This is especially important for active individuals and athletes because your electrolyte needs will increase due to this hormonal change.
Cortisol is our main stress hormone, produced by the adrenal glands and regulated by the pituitary gland and hypothalamus in the brain. Cortisol levels increase acutely during times of stress. They also can be chronically elevated due to chronic stress, inflammation, and blood sugar dysregulation.
Cortisol plays a complex role in how it affects fluid balance, both directly and indirectly! To keep it simple, cortisol is directly correlated to ADH levels. This means that greater cortisol production can mean greater fluid retention. Cortisol also increases the speed at which blood passes through the kidneys (aka glomerular filtration rate), increases phosphate and potassium excretion, and sodium and water retention.
The Role of Electrolyte Balance in Period Bloating
Electrolytes are essential minerals that are important for countless body functions, one of which is balancing fluid within our tissues. Electrolytes include sodium, potassium, magnesium, chloride, calcium, and phosphate.
You can see that there are a variety of factors that impact fluid regulation, especially by way of impacting electrolyte levels. That being said, electrolyte imbalances can exacerbate these effects and therefore cause significant water retention especially leading up to the menstrual cycle.
With these hormonal fluctuations in mind, we can help combat these imbalances and effects with strategic dietary intake of electrolytes. During the follicular phase, progesterone levels remain low, and estrogen levels increase as we approach ovulation. Consuming more sodium especially during the follicular phase can help offset the increase in sodium loss during this time.
During the luteal phase, our kidneys retain more sodium, which we can balance out by consuming more potassium. Balancing out sodium and potassium helps more effectively move fluid in and out of cells and between tissues, decreasing water retention!
In Need of Answers?
If you consistently feel puffy, bloated, or like you gain weight prior to your period, electrolyte imbalance could be a culprit. An imbalance between progesterone and estrogen, as well as high or low cortisol levels may also be at play. Check out our DUTCH testing package to test these hormones and get to the bottom of your period bloating and water retention!
Written by Romana Brennan, MS, RD
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