How to Read a Cannabis Label in Ontario: THC%, CBD, Terpenes & Batch Info

Every legal cannabis product sold in Ontario carries a standardized label regulated by Health Canada under the Cannabis Act and Cannabis Regulations. Learning how to read a cannabis label means understanding the standardized cannabis symbol, total THC and CBD percentages, terpene declarations (when included), packaged-on dates, and lot/batch numbers: all of which help you make informed purchases. At Ashario Cannabis, our budtenders walk customers through label reading every day, and this guide consolidates the questions we hear most often at our four GTA locations.

Updated May 2026, this article breaks down every element you'll see on a cannabis package in Ontario, from the yellow standardized cannabis symbol to the difference between "Total THC" and "THC" on dried flower, why terpene percentages matter, and how to use the packaged-on date to judge freshness. Whether you're shopping flower, vapes, edibles, or concentrates, the same labelling framework applies.

What Information Must Appear on Every Ontario Cannabis Label?

Health Canada requires every legal cannabis package in Ontario to display: the standardized cannabis symbol (yellow stop-sign with a cannabis leaf and "THC"), a yellow health warning message, the brand name, product class (e.g. dried cannabis, extracts, edibles), net weight or volume, total THC and total CBD content, the Licensed Producer's name and address, packaged-on date, lot/batch number, and an expiry date if applicable. These rules apply to every product sold through authorized retailers like Ashario.

This standardized format means that no matter which Licensed Producer made the product (Redecan, Pure Sunfarms, BZAM, Hexo, Tweed, or any other) the core information appears in predictable places. When customers visit our Ashario store locations, our team can quickly pull up any product and walk you through the label, but knowing what to look for yourself speeds up the process.

The Standardized Cannabis Symbol

The yellow octagonal symbol with the cannabis leaf and "THC" letters is mandatory on any product containing more than 10 micrograms of THC per gram. It signals that the product is intoxicating. CBD-only products without measurable THC do not require this symbol, which is one quick way to identify low-THC wellness products on the shelf.

How to Understand THC Percentage on a Cannabis Label

The THC percentage on a label represents the concentration of tetrahydrocannabinol by weight in the product. For dried flower in Ontario, you'll typically see two values: "THC" (the active form, delta-9-THC) and "Total THC" (the active form plus THCA converted after decarboxylation). Total THC is the more practical number because heating the flower, through smoking or vaping, converts THCA into active THC. Most premium Ontario flower lands between 18% and 32% Total THC.

For more on potency selection across product categories, see our cannabis product categories page where every SKU lists its lab-verified percentages. A few key facts our budtenders share with new customers:

• THC %: Active delta-9-THC at the time of testing | usually a small number like 0.5% on raw flower.
• Total THC %: The number that matters for effects after combustion or vaporization.
• mg/g: Edibles and oils list THC in milligrams per gram or per unit, capped at 10 mg per package for edibles under federal regulation.
• mg/mL: Beverages and tinctures use volume-based measurements.

Why Two Bottles of the Same Strain Can Have Different THC%

Cannabis is an agricultural product, so each harvest (each lot) tests slightly differently. A strain like Wabi Sabi might be 26% Total THC in one batch and 28.5% in the next. This is why the lot/batch number matters. It ties the percentage on the label to a specific harvest and lab certificate.

CBD on Cannabis Labels Explained

CBD (cannabidiol) is listed separately as "CBD" and "Total CBD" using the same logic as THC. Total CBD includes both active CBD and CBDA converted after heating. In Ontario, you'll see three common label profiles: high-THC/low-CBD (typical recreational flower), balanced 1:1 products where THC and CBD percentages are roughly equal, and high-CBD/low-THC products often labelled with terms like "20:1" indicating 20 parts CBD to 1 part THC.

Customers frequently ask us at the Ashario Cannabis counter whether a "high CBD" label means there's no THC at all. The answer is almost always no: most CBD-dominant products still contain trace THC, and the standardized cannabis symbol will appear if total THC exceeds 10 µg/g. Always check both numbers before buying.

Terpenes on Cannabis Labels: What the Percentages Mean

Terpenes are the aromatic compounds responsible for cannabis flavour and scent: myrcene (earthy, mango), limonene (citrus), caryophyllene (peppery), pinene (pine), linalool (floral), and terpinolene (herbal-fruity) are the most common in Ontario flower. Total terpene content on a premium cannabis label typically ranges from 1% to 4% by weight, with anything above 2.5% considered high-terpene "premium" or "craft" flower.

Not every Licensed Producer prints individual terpene percentages on the package, but a growing number, especially craft producers stocked at Ashario, now disclose the dominant three or four terpenes on the label or QR-code-linked Certificate of Analysis (COA). Reading terpene data lets you anticipate flavour and aroma far better than just reading "indica" or "sativa." Two unique points our team highlights:

• Total terpene % is a freshness indicator: Terpenes degrade over time. A flower packaged 14 months ago will have noticeably fewer volatile terpenes than one packaged six weeks ago, even if THC stays stable.
• Dominant terpene predicts experience better than chemovar labels: Myrcene-dominant cultivars tend to feel heavier; limonene and terpinolene-dominant cultivars tend to feel lighter, regardless of whether the label says "indica" or "sativa."

Where to Find Full Terpene Profiles

If a label only lists total terpene percentage, scan the QR code on the package or look up the lot number on the Licensed Producer's website. Most LPs publish full COAs that break out each terpene to two decimal places. Our blog at Ashario Cannabis blog regularly reviews specific cultivars and their dominant terpenes.

Label Explained: Packaged-On Date and Batch Numbers

The packaged-on date on an Ontario cannabis label tells you when the product was sealed, not when it was harvested or when it expires. Vapes, edibles, and concentrates often carry explicit expiry dates because their stability profiles differ from flower.

The lot or batch number is the most underutilized piece of information on any cannabis label. It allows you to:

1. Look up the exact Certificate of Analysis for that specific harvest.
2. Identify the product if there's ever a Health Canada recall.
3. Re-order the same batch when you find one you love (helpful at our Ashario locations where staff can check incoming inventory by lot).
4. Track terpene and potency variation across harvests of the same strain.

How Fresh Is "Fresh" for Ontario Flower?

Based on what passes through our four stores: flower packaged within the last 90 days is exceptional, 90 to 180 days is very good, 6 to 12 months is acceptable for most consumers, and beyond 12 months you'll notice diminished aroma even if THC remains potent. Vapes generally maintain quality for 12 to 24 months when stored upright in a cool place.

Cannabis Packaging Info for Edibles, Vapes, and Concentrates

Different product classes use slightly different label conventions, all standardized under the Cannabis Act:

• Edibles: THC capped at 10 mg per package. Labels show mg per unit (e.g., 5 mg per gummy x 2 gummies = 10 mg total). Ingredients, allergens, and nutrition facts are mandatory.
• Vape cartridges: List total THC/CBD as a percentage of the oil, total mg in the cartridge, and oil volume in mL. A 1.0 mL cart at 80% THC contains roughly 800 mg of THC.
• Concentrates (shatter, rosin, resin, hash): Capped at 1000 mg (1 g) of THC per package. THC percentage is typically very high: 60 to 90% for shatter, 70 to 85% for live resin.
• Pre-rolls: Show total THC of the flower used and the weight of each joint (commonly 0.35 g, 0.5 g, or 1 g).
• Beverages: Capped at 10 mg THC per container, listed in mg per mL.

For any product question, our staff are reachable through the Ashario Cannabis contact page or by phone at any of our four locations: Finch & Dufferin (647-368-7722), Centerpoint Mall (416-477-9333), Aurora (905-503-6770), or Thornton (249-733-9333).

Ontario-Specific Label Rules You Should Know

Ontario follows federal Health Canada labelling rules. The legal age to purchase is 19+, the standardized cannabis symbol is mandatory on all THC-containing products above 10 µg/g, and plain packaging rules limit branding to one logo, one brand name, and a single brand element. This is why every Ontario cannabis package looks visually similar: colourful, glossy, or "lifestyle" packaging is prohibited.

One note: every product sold at Ashario Cannabis has cleared Health Canada testing for pesticides, heavy metals, microbial contaminants, and potency accuracy. Unregulated or grey-market products carry no such guarantee: the label itself is part of the safety system.

Frequently Asked Questions About Cannabis Labels in Ontario

What does "Total THC" mean on a cannabis label?

Total THC represents the maximum potential delta-9-THC available in the product after decarboxylation (heating). It's calculated by adding the active THC already present plus the THC that will be converted from THCA when the cannabis is smoked, vaped, or cooked. For Ontario flower, Total THC is the realistic potency number to compare across products: a label showing 0.4% THC and 24% Total THC means you'll experience the effects of roughly 24% THC when consumed.

How do I know if cannabis is fresh from the label?

Check the packaged-on date, which is required on every Ontario cannabis package. Flower within 90 days of packaging is considered very fresh; within 6 months is generally good; beyond 12 months you may notice reduced terpene aroma although THC remains relatively stable. Vapes and concentrates have longer shelf lives. At Ashario, our budtenders can tell you the packaged-on date of any in-stock product before you buy.

Why do two packages of the same strain have different THC percentages?

Cannabis is an agricultural crop, and each harvest produces slightly different cannabinoid levels based on growing conditions, harvest timing, and curing. Each batch is independently tested, and the label reflects that specific lot's results. Variations of 2 to 4% THC between batches of the same cultivar are completely normal. The lot number on the label connects to that batch's unique Certificate of Analysis.

Are terpene percentages listed on every cannabis label in Ontario?

No. Health Canada requires THC and CBD declarations but does not mandate terpene disclosure. However, many Licensed Producers, particularly craft and premium brands, voluntarily list total terpene percentage and dominant terpenes either on the package or on a QR-code-linked COA. Stores like Ashario stock many high-terpene craft options where this information is published.

What is a lot or batch number used for?

A lot number identifies the specific harvest and processing run of the product. It's used for traceability. Health Canada uses it for recalls, Licensed Producers use it to track quality, and consumers can use it to look up the exact Certificate of Analysis showing pesticide screens, microbial tests, and full cannabinoid and terpene breakdowns. If you find a batch you love, recording the lot number lets you ask retailers if the same lot is still in stock.

Does a higher THC percentage always mean a stronger experience?

Not necessarily. THC percentage measures potency by weight, but the overall experience is shaped by terpenes, minor cannabinoids (CBG, CBN, THCV), individual tolerance, dose, and consumption method. Many experienced customers at our four Ashario locations specifically seek out lower-THC, high-terpene flower (18 to 22% Total THC with 3%+ terpenes) over higher-THC, lower-terpene options because the experience is more nuanced. Always read the full label, not just the THC number.

Visit Ashario Cannabis for Help Reading Any Label

Ashario Cannabis operates four locations across the Greater Toronto Area, all open from 7:00 AM to 11:00 PM, 365 days a year: Finch & Dufferin in North York, Centerpoint Mall on Yonge Street, Aurora on Yonge Street, and Thornton on Barrie Street. Every budtender on our team is trained to walk you through cannabis labels (THC and CBD percentages, terpene profiles, packaged-on dates, lot numbers, and Licensed Producer details) so you can choose products with confidence. Browse our full cannabis product categories, read more guides on the Ashario blog, or stop into any Ashario store location for a label walk-through in person.