“In Vitro” Versus “In Vivo”
There is a difference between “in vitro” and “in vivo” when it comes to scientific testing and research.
- “In vitro” refers to performing an experiment or procedure outside of a living organism in a controlled environment, such as in a test tube or petri dish.
- “In vivo” refers to performing the experiment or procedure within a living organism, such as an animal or human.
This distinction is important because it is incredibly common for in vitro studies to not directly translate to in vivo studies when it comes to the results or expected outcomes. Testing something in a test tube is very different from testing something outside of that controlled environment in a real, living creature.
This is not to say that in vitro studies aren’t useful. But as with anything with science, they need to be taken with a grain of salt and not as absolute proof. Additionally, it is also common for the results of animal studies done in vivo to not be able to be replicated when tried in human studies.
Why This Matters
The reason this is important to understand is because the vast majority of studies demonstrating the potential of CBD to convert to THC in the stomach was done in vitro, not in vivo.
Of the very few done in vivo, there was no evidence to support the claims that CBD converted to THC within the body. For example, this March 2020 study concludes that CBD taken orally will not convert into THC in humans.
Furthermore, many question the validity of the original in vitro studies because of inconsistent findings.
It’s not uncommon for people to test positive on a drug test for THC even when taking CBD products that are marketed as “THC free.” Some point to this as proof that CBD converts to THC in the body.
The reality likely has to more to do with how third party lab equipment is calibrated, and less with the human body. It is very difficult to remove all traces of THC in CBD products made from pure isolate. And while the isolate can be made quite pure (99.9+%), companies still have yet to achieve a truly 100% pure product.
Testing equipment at third party labs have something called a lower detection limit. This means that their equipment can only detect down to a certain amount. So the product may be free of THC over a certain detection limit, but it can still have trace amounts not being detected below the limit. Initial use of these products is unlikely to yield a positive drug test, but prolonged use certainly increases the risk.
As of right now, there is little to no evidence to suggest that CBD converts to THC in the body when ingested orally.
The World Health Organization’s report on CBD states the following on the conversion of CBD to THC: “Overall, there is no evidence that this transformation occurs in humans after oral CBD administration.”
We believe that it is more likely for one to test positive on a drug test when taking “pure” CBD products because of trace amounts of THC still in the CBD isolate.