Storage: why that bottle is brown and the fridge isn't a good idea.

Why does CBD oil come in a dark bottle?

To keep the light out. Ultraviolet light breaks down plant compounds, and cannabinoids are no exception. A brown or green glass bottle filters out most of it, and the box around it does the rest.

That also matters for where you put it. A bottle on the windowsill or next to the cooker is in the two worst places imaginable. A kitchen cupboard or a drawer is fine.

What does heat do?

Heat speeds up almost every breakdown process, including this one. At room temperature little happens; at thirty degrees in a car in the sun, or right above a radiator, it goes faster. Keeping it cool here simply means room temperature or a little below.

The fridge isn't necessary, and it has a downside. Plant oil turns thick and syrupy there, so the dropper works less evenly and counting drops gets harder. On top of that, some condensation forms every time you put it back. So you are better off keeping the bottle in a cupboard.

And oxygen?

Every time you open the bottle, air gets in. Oxygen slowly makes the carrier oil go rancid, just as it does with the olive oil in your kitchen. Which carrier is used matters here, because some oils are more sensitive than others; which product has which base is on the page about carrier oils.

So screw the cap on tightly and don't leave the pipette loose in the bottle.

How long does a product stay good?

The best-before date is on every pack, and that is what counts. It is the date the producer uses for an unopened product stored normally.

For the period after opening, there is no general rule of thumb we could write down here with a straight face, and we haven't formally set that instruction for each Renova product yet. We'll add it to the product pages once we have checked it against the label. What we can say: at a few drops a day, a 10 ml bottle lasts about a month and a half, so in practice it usually runs out before the date comes into view. Under the oils you'll find how many drops each strength holds.

How can you tell an oil is past its best?

By smell and taste, as with any other plant oil. Rancid oil smells sharp or musty and tastes bitter in a way you are not used to from the product. A strongly changed colour or a cloudy bottle is also a sign.

An important distinction: this tells you something about the carrier oil, not automatically about the amount of CBD. The reverse also applies. An oil that looks fine could in theory contain fewer cannabinoids than when it was bottled, because you can't see or smell that breakdown. If in doubt, throw it away; it isn't a product you need to take risks with.

Do different rules apply to capsules, patches and skin products?

The principles are the same: cool, dry, dark, cap closed. With capsules, moisture matters more than light, so make sure the jar closes properly and don't keep it in a steamy bathroom. Patches should stay in their own sealed packaging until you use them. Skin products follow the instructions on the label.

For all products: keep them out of the reach of children. CBD products are not meant for children, which is explained further on the safety page, along with why pregnant women, people who take medication and people with a liver condition should talk to a doctor first.

In short

• A cupboard or a drawer, not the windowsill and not next to the heater.
• Room temperature is fine; the fridge only makes the oil thick.
• Cap on tightly after use.
• The best-before date on the pack is what counts.
• If it smells or tastes sharp, musty or unusually bitter: throw it away.

More basic information about CBD is in the knowledge base overview.