Water Retention aka Edema

TL:DR Androgens and salt are associated with edema, with different reasons. Be conscious of sodium when on cycle.

What is water retention?

Fluid retention or edema means that there is excessive water in the tissue of the body which causes the body to swell.... Fluid retention is often caused by the increase of blood pressure on the veins which adds to the pressure on the capillaries.

For our purposes, edema can be caused by PEDs and symptoms will include puffiness/swelling, reduced flexibility, tight or stiff skin. It’s common with PED use, at even moderate doses: 300mg is associated with edema, and presumably higher amounts of androgens will result in higher amount of water retention.

Causes: 20-HETE & Renin-Angiotensin

Edema often includes the retention of salt and water with increased capillary hydrostatic pressure. That last part refers to fluid forcing its way out of the circulatory system, bringing oxygen and nutrients to surrounding cells. As it sounds, the action of fluid leaving your capillary is usually good, however when it is being forced out at a velocity akin to what we might see on /r/powerwashingporn and in quantities which might be seen on /r/squirting, it leads to edema, and can cause damage to cells, organs and blood vessels. Two causes of this include a metabolite called 20-HETE and the Renin-Angiotensin system. Both help regulate sodium and fluid transport in and out of the kidneys.

It’s not within the scope of this article to talk about either MOA (which seems highly complex, not well understood and rather confusing), and it’s not relevant to most of us anyway, so the high level points are outlined below:


  • At natty hormone levels, 20-HETE helps regulate blood pressure
  • Androgens stimulate 20-HETE production
  • This causes sodium to be reabsorbed into the bloodstream
  • 20-HETE is vasoconstrictive normally useful for repairing blood vessels. On cycle, the result of the up-regulation of 20-HETE is greater vasoconstriction, a retaining of sodium and fluid and edema.


  • When blood blow to the kidneys is reduced, renin is increased, in an inverse relationship and ultimately is transformed into angiotensin II.
  • Angiotensin II is a vasoconstrictor that causes vessels to narrow and increases blood pressure which paradoxically helps the kidneys filter blood despite the reduced blood flow due to the increased pressure.
  • Angiotensin II stimulates creation of aldosterone which causes reabsorption of sodium and water into the blood, and edema

Causes: Estradiol & Prolactin

Estrogens exert a moderate sodium-retaining effect, reducing excretion of sodium and water without affecting potassium. How it does this is a) adrenal via an increased production of aldosterone (see renin-angiotensin above), or b) non-adrenal. In a study of castrated males, estrogen therapy caused edema in 3 out of the 4 patients, with 2 gaining 2-5kg on a calorie controlled and normal sodium diet. (Note: the last patient who did not get edema from the estrogen therapy was put on a very low sodium diet - no edema was present).

In a second study, 11 subjects were injected with estradiol monobenzoate 10mg daily IM (0.14-0.20mg per/kg). The findings were that there was an increased retention of sodium and water, leading to a modest increase in weight and changes in water balance. The cause in this case was hypothesized to be in the kidney. Diet included normal levels of sodium.

In respect to the effect that prolactin has, a third study of 19 patients monitored prolactin levels. A correlation was found between high prolactin values and low natriuresis (excretion of sodium when you pee). This, plus electrolyte changes, suggests that prolactin causes sodium retention.

Root Cause: Sodium & Albumin

The common thread to 20-HETE, Angiotensin, Estradiol & Prolactin is sodium. All the actions that increase water retention include sodium - so what’s the deal? I drink water, and for some reason the sodium means that I hold on to that water. How does that work?

Sodium is an electrolyte that regulates cellular fluid levels in the body, while potassium acts as a flushing mechanism eliminating waste. Higher amounts of salt signals a higher demand for fluid at each cell. Conversely, low potassium can mean that cells are not being flushed, and also result in water retention as salt & fluid is not being removed from cells.

The conclusion here should be obvious, but let me get to that.

Other causes of edema include heart failure, liver and kidney disease, and low albumin. The former I don’t expect to be a leading cause, and besides you’re unlikely to be running PEDs if you’re on dialysis. However low albumin may be another cause of edema. Put very simply, albumin is a protein binds to hormones which must be released before they are active and prevents the compounds it is bound to from being pushed outside the capillary. A liver function test will return this value.

Am I Gonna Make It Doc?

Some water retention is inevitable when using androgens, but let’s face it nobody wants to be a walking water balloon. My recommendation is based on prevention:

  1. Sesamin at 50mg, or roughly 25g of sesame, daily significantly lowered 20-HETE without affecting blood pressure or sodium levels.
  2. Protein increases albumin levels. So, eat protein.
  3. Monitor and manage your e2 and prolactin levels.

But most critically, reduce the salt in your diet when on-cycle. This will reduce the amount of salt that 20-HETE (and aldosterone) has available to reintroduce to the body, as well as estradiol and prolactin, and prevent the edema causing cycles outline above. You can add in a few bananas a day, to ensure that you’re able to flush out your cells, but high sodium will mean that some of this gets reintroduced back into the circulatory system.