Forbes reports

CBD water is a perfect example of capitalism at its phoniest. While plenty of companies are looking to cash in by claiming their products contain beneficial CBD, CBD water is the easiest example of how a fool and his money are soon parted.

CBD or cannabidiol, the low THC product that everyone touts as being “the non-psychoactive form of cannabis,” (which in and of itself is slightly misleading, but that is for a different column) destabilizes when exposed to light or oxygen. Legitimate CBD products are sold in dark, opaque bottles with labels that warn the consumer to store the bottle away from light, in a cool, dark place.

Scientists are just beginning to understand how hemp-derived CBD is beneficial to the human body’s endocannabinoid system. Depending on the manufacturing process, the minuscule amount of CBD that CBD water contains is most likely rendered ineffective when it is exposed to light for an extended period of time, such as being stationary in a brightly-lit supermarket refrigerator or storage facility all day. CBD products should be kept out of direct light, in order for the CBD not to destabilize.

Some manufacturing processes may be able to keep the components stable while exposed to light in the short term, but it will not remain stable if the water is sitting on a shelf for months or even weeks.

That means CBD in a clear water bottle stored on a brightly-lit supermarket shelf is most likely completely useless and provides no other benefit than the regular hydrating effect of plain water.

Assuming some manufacturer takes the initiative to sell CBD in dark brown glass bottles, like Guinness, from the moment the cap is opened and oxygen hits the product, it begins to destabilize.

Therefore, putting a dropper full of CBD into a bottle of water and sipping it here and there is not advisable either. Opening and closing the bottle numerous times and allowing oxygen and light to penetrate the container weakens the CBD, rendering it all but ineffective, quite quickly. (Unless fitness buffs do this at Soul Cycle, where the room is pretty dark and cyclists tend to chug.)

More at

https://www.forbes.com/sites/sarabrittanysomerset/2019/02/24/why-cbd-water-is-not-really-a-thing-and-may-even-be-dangerous/#3fe735b8ac07