It’s better to estimate how long a bottle of CBD will last based on the total CBD content rather than the size of the bottle. A one-ounce / 30-milliliter bottle of CBD oil will last depending on your circumstances and the potency of the bottle.
If you take 30 mg of CBD daily, a 1,000 mg bottle of CBD oil will be about a one-month supply. However, most people require more CBD on some days, and less on others. If you need 50 mg of CBD daily, then you may want to go for 1,500 mg bottle sizes or more to last you for one month.