The use of diuretics in bodybuilding

25. 6. 2025.

What are diuretics?

Diuretics belong to the category of drugs that increase the amount of water and sodium in the body, which are later eliminated from the body through the urinary tract (constant need to go to the toilet).

For medical purposes, it is used, for example, to expel excess fluid from the body in patients who have a problem with hypertension (high blood pressure).

In bodybuilding, diuretics have become one of the most popular ways to achieve a shredded body before going on stage, despite the fact that they belong to the group of prohibited substances (unfortunately, their abuse occurs).

Many competitors see diuretics as magic pills that will help them reduce excess fluid in the body.

But like everything in life, diuretics have their good and bad sides.

The diuretics most commonly used in bodybuilding are:

  1. Lasik
  2. Aldactone (Spironolactone)
  3. Diazide (Thiazide)

Lasiks falls into the category of the most commonly used drugs due to (you guessed it) low price.

It belongs to the group of the most powerful diuretics, which is most often used to reduce blood pressure (in case of hypertension), swelling, toxins in the blood… LaZix acts directly on the kidneys, in which, together with water, it “cleanses” the body of sodium, calcium and other important nutrients.

The downside of Lapix is that it can cause serious side effects such as blood clotting, low blood pressure, renal failure (a decrease in kidney function resulting in the accumulation of nitrogenous substances in the blood, which will result in the cessation of urine excretion).

Aldactone (Spironolactone) also works on the kidneys, but compared to Lapix, it has fewer side effects. It belongs to a milder diuretic drug that should not be used more than 2 – 3 times a day and no longer than 2 days (50mg per day divided into two to three doses). The main thing about this diuretic is that it doesn’t remove potassium from the body (like LaPix does). This tells us that the additional use of potassium in combination with Aldactone is superfluous, otherwise we risk upsetting the balance of nutrients and electrolytes.

Diazid is similar to Aldactone in that it does not eliminate potassium from the body. So, there’s a similar rule. Potassium supplementation is not required, and the use of diazide should be limited to two days. These days are the night before and on the day of the competition (one 12mg tablet per use).

For this reason, the key thing for “bodybuilders” when using these medications is the time of use of them, because otherwise the “curves of the body” can be very easily disturbed.

What’s the conclusion?

Diuretics in “bodybuilding” can indeed help competitors reduce “excess” fluid from the body and thus get a satisfactory appearance on the day of the competition, but are they willing to pay the price with their health?

Heart, kidney, cramps, mental problems, or even heart attacks are possible when diuretics are abused.