Because CBD oil is relatively new to the market, there are many misconceptions surrounding it. Here are a few of the most common ones:
CBD gets you high - Though CBD comes from the cannabis plant, it is not an intoxicant and will not get you high. Extensive clinical trials have demonstrated that ingested CBD, even at very high doses, does not cause THC-like effects. There is no evidence that the consumption and usage of CBD oil has a similar effect to smoking cannabis.
Will CBD show up on your drug test - CBD itself will not show up on a drug test. When drug testing for marijuana, routine tests screen for THC specifically, and not the host of other cannabinoids. It is highly unlikely, but as everybody is different and depending on the frequency and dosage of a Full Spectrum CBD Oil, the trace amount (<0.3%) of THC may build up in your system and cause you to test positive. If failing a drug test is a concern, we suggest taking a Broad Spectrum CBD oil as it has 0.0% THC.
High doses work better than low doses - A number of studies on animals have shown a bell curve response to CBD dosage level. This means that doses too low or too high may not result in the desired effects. For certain individuals, a low dose of CBD could be more effective than a high dose.
CBD can turn into THC in your stomach - There have been a couple of contradictory studies regarding the conversion of CBD into THC in the stomach. CBD and THC have similar chemical structures, and under acidic conditions, CBD can be transformed into THC and other cannabinoids. However, the general consensus is that this conversion seems not to occur in humans. A more recent study claimed, “the conversion of oral CBD to THC and its metabolites has not been observed to occur in vivo [inside a living organism], even after high doses of oral CBD.” 
 Leafly Article
 NCBI Article