How to Read a Cannabis Label: A Simple Guide

Cannabis packaging contains plenty of numbers and information. But what do they mean? Understanding a few key details can help you compare products, check what’s inside, and avoid confusing the strength of one piece with the strength of an entire package.



Start with THC and CBD

THC is the main cannabis compound responsible for feeling high. CBD does not produce the same intoxicating effect, although it can still affect the body and brain. Check both amounts when reading a label.

What does “Total THC” mean?

On some products, you may see both THC and Total THC.

THC describes the THC already present. Total THC also accounts for the potential conversion of THCA into THC when heated. This distinction is particularly useful when reading flower and pre-roll labels.

Don’t add THC and Total THC together: Total THC already includes the existing THC. The same principle applies to CBD and Total CBD.

Understand the Units: mg/g, Percentages, and Milligrams

The unit beside the number matters.

For flower, mg/g means milligrams per gram. To convert mg/g into a percentage, divide by 10:

• Label shows 150 mg/g: Equivalent percentage 15%
• Label shows 200 mg/g: Equivalent percentage 20%
• Label shows 250 mg/g: Equivalent percentage 25%

  For example, Total THC: 200 mg/g means a THC concentration of 20%. It does not mean the entire package contains only 200 mg of THC.

Edibles and beverages generally display THC in milligrams, so read whether the amount refers to one piece or the whole package.

Check the Amount per Piece and per Package

Imagine a package containing five pieces, each with 2 mg of THC. The whole package contains 10 mg of THC.

Before consuming an edible, check:

• How many pieces are inside?
• How much THC is in each piece?
• How much THC is in the whole package?

A package total is not a suggested serving size. Edibles can take up to four hours to reach their full effects, and consuming more too soon can increase the risk of adverse effects.

Look at Product Size and Packaging Date

Check the net weight or volume and the number of units. For example, 3 × 0.5 g pre-rolls means three pre-rolls containing 1.5 g altogether.

The packaged-on date tells you when the product was packaged. It is different from a harvest date or expiry date.

Keep the lot number, too. It identifies the batch and helps the manufacturer investigate a product concern.

Read the Warnings, Ingredients, and Storage Instructions

The yellow health warning box contains information about cannabis risks. Edible labels also include ingredients, allergen information, and nutrition facts.

Follow the storage directions and keep cannabis securely out of reach of children and pets. Health Canada recommends starting with a low amount of THC and waiting to feel the effects before taking more. Never drive while impaired.

Have a Label Question?

Bring your questions to the team at Rainbow Cannabis in Thunder Bay. Whether you’re comparing package sizes or trying to understand THC numbers, asking before you buy can help make the information clearer.