Research showing how long CBD is detectable in urine is scarce, but one study showed that a single test subject kept detectable CBD in his urine for only 24 hours. Most of the CBD taken is excreted in the faeces within a day or two of the first dose, and about a quarter of the CBD is excreted in the urine. According to studies on THC detection times, moderate to large daily doses of CBD (10-100 mg) should be eliminated from the urine within a couple of weeks. Normally, these metabolites can show up in a urine test within three days to two weeks after the last intake.
CBD (or cannabidiol) is stored in the body's fat cells and can theoretically remain detectable for days or even weeks in a blood test. This is more likely to happen if the CBD you buy is marijuana-derived CBD rather than hemp-derived CBD. Like full-spectrum CBD products, broad-spectrum CBD products contain additional compounds found in the plant, including terpenes and other cannabinoids. Therefore, broad-spectrum CBD products are less likely to contain THC than full-spectrum CBD products.
Remember that CBD products derived from marijuana, along with full-spectrum CBD products derived from hemp, are more likely to contain THC. This is because all the THC is removed in full-spectrum CBD, unlike full-spectrum CBD, which contains all the compounds that occur naturally in the plant from which they are extracted. The half-life of inhaled or smoked CBD in the blood plasma is much shorter than that of ingested CBD, only a few hours. The duration of CBD's effects depends on several factors, including the user's metabolism and whether he or she uses CBD regularly.
The highest bioavailability (the amount that is absorbed and enters the bloodstream) comes from ingested or smoked CBD, while CBD oil tinctures applied sublingually (under the tongue) come second.