What is Stevia
Stevia is a sweetener and sugar substitute extracted from the leaves of the plant species Stevia rebaudiana.
The active compounds of stevia are steviol glycosides (mainly stevioside and rebaudioside), which have up to 150 times the sweetness of sugar,are heat-stable, pH-stable, and not fermentable. These steviosides have a negligible effect on blood glucose, which makes stevia attractive to people on carbohydrate-controlled diets. Stevia’s taste has a slower onset and longer duration than that of sugar, and some of its extracts may have a bitter or licorice-like aftertaste at high concentrations.
The legal status of stevia extracts as food additives and supplements varies from country to country. In the United States, stevia was banned in 1991 after early studies found that it might be carcinogenic; after additional studies, the FDA approved some specific glycoside extracts for use as food additives in 2008. The European Union approved stevia additives in 2011 and in Japan, stevia has been widely used as a sweetener for decades. 
Learn more about the plant, how to grow your own and why stevia may or may not be appropriate for everyone.
Please watch: Stevia Sweetener, A Natural Non-Glycemic Herbal Sugar Substitute
Is Stevia Safe? Are There Stevia Side Effects?
Most people do well with stevia, but listen to your body because stevia is an herb and everyone’s body may react differently to it. The benefits and possible stevia side effects really depend upon what stevia you choose to consume.
Highly refined varieties of stevia are considered by the FDA to be generally recognized as safe. Since highly processed stevia starts as a natural substance but gets so significantly refined, the FDA finds it hard to label stevia products like Truvia. It labels highly processed types of stevia as novel sweeteners. Novel sweeteners are combinations of various types of sweeteners.
The FDA has not approved whole-leaf stevia or crude stevia extracts as GRAS, although they’re much more natural than the stevia products it’s given its stamp of approval. With whole-leaf and crude extracts, benefits are greater and negative stevia side effects are less likely.
When it comes to the stevia options available today, it’s vital to know that not all stevia is created equal. You should be aware of the three main categories of stevia, including green leaf stevia, stevia extracts and altered stevia (like Truvia).
Green leaf stevia is the least processed of the stevia types. The leaves are basically just dried and ground into powder form. This is the type of stevia that’s been used in South America and Japan for centuries as a natural sweetener and health remedy. This type of stevia is about 30–40 times sweeter than sugar.
Some brands that make stevia extracts extract the sweeter and less bitter part of the stevia leaf (rebaudioside), which doesn’t have the health benefits found in stevioside. This type of stevia may be a better option than other regular sweeteners, but there aren’t many studies available yet showing its effects.
The worst option is altered and overly processed “stevia” like Truvia. It’s really not stevia at all by time a product like Truvia goes through a 42-step process to make this processed sweetener. First, the rebaudioside is extracted from the stevia leaf, and then chemical solvents are added, including acetonitrile, which is toxic to the liver and is a carcinogen. Then the producers add in a GMO corn derivative called erythritol. Truvia or rebaudioside stevia products are about 200 to 400 times sweeter than sugar.
Negative Stevia Side Effects
This point cannot be stressed enough: Not all stevia products are created equal. There is a HUGE difference between consuming real stevia and chemically processed stevia products like Truvia.
Truvia only contain less than 1 percent stevia. Yes, you read that correctly — LESS THAN 1 PERCENT! Truvia is really barely a stevia product, but people unfortunately believe that this sweetener is natural and harmless. If you avoid Truvia and choose the right stevia product, then dangerous stevia side effects are basically nonexistent — unless, of course, you have a ragweed allergy.