Have you spent 60 quid on CBD oil and it fills like it doesn't work? There may be several reasons and not necessarily it means a problem with the oil.
Fortunately, it usually is a problem with your CBD product. If your CBD containing product does not come from a reliable source it may not contain as much CBD as advertise. CBD market is not yet regulated and there are manufacturers, who use poor quality ingredients of lower than required purity. There may be a few, who knowingly cheat on CBD content as CBD is relatively expensive.
Frequent cannabis users may develop a higher tolerance of cannabinoids in time. This may also affect CBD tolerance. Combined with low purity may render many products useless.
The human body sometimes needs to adjust to CBD as some people don't have enough CBD compatible receptors on their cells. It may take up to a month to fully benefit from positive effects of CBD product
Always go for quality products. You'll recognize them by the way they are made. Cheap vial with shoddy sticker should always raise the alarm. In the case of oils and tinctures always look for a glass bottle. Amber or black. Companies with established products often invest in custom packaging with permanently printed containers/bottles. Look for organic - it is always worth it. It is good to be able to see certificated and lab tests, but they can be faked, out of date or from a different batch. So don't rely on them. Finally, a good CBD product doesn't have to cost you arm and leg. but don't expect to get 30ml of oil with 2000mg of CBD for less than £60.
So if your CBD doesn't work, it most likely means that you have wrong CBD product. Just try something else.