Generally, stevia is thought to be metabolized and excreted without accumulating in the body.
Stevia’s sweetness comes from steviol glycosides. Steviol glycosides are a group of substances, among which stevioside and rebaudioside A are the two most common in commercial products.
Our stomachs and upper small intestines cannot break down or absorb steviol glycosides. Therefore, ingested steviol glycosides enter the lower gastrointestinal tract intact. In the colon, gut bacteria break down steviol glycosides into steviol, a process completed within 24 hours. Subsequently, most of the steviol is rapidly absorbed into the bloodstream through the intestinal wall, while any unabsorbed steviol is excreted in feces. The steviol entering the bloodstream is further metabolized into steviol glucuronide in the liver and ultimately excreted in the urine. This is why human experiments have shown no detectable levels of steviol in the blood after consuming steviol glycosides, while steviol glucuronide is detected in urine, and steviol is found in the feces.
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