Reading a Medical Cannabis Label: THC, CBD, Terpenes and Batch Data

A medical cannabis label can look like a wall of numbers. But those figures aren't decoration — they're exactly how you and your prescriber dose safely. This is a plain-English guide to reading a NZ medical cannabis label, whether it's an oil bottle or a jar of flower.

Information and education, not medical advice. Always dose according to your prescriber's instructions. 18+.

Why the numbers matter

The whole advantage of a verified medical product over illegal-market cannabis is that the label is accurate — tested to meet the Medicinal Cannabis Scheme's quality standard. (See our piece on how cannabis is tested.) That accuracy is what makes "start low, go slow" meaningful: you can only titrate a dose you can actually measure.

The cannabinoid figures

The two headline numbers are almost always THC and CBD. How they're expressed depends on the format.

For oils

Oils usually state cannabinoid content as a concentration — milligrams per millilitre (mg/mL) — and sometimes a total per bottle. For example, a label might read:

• THC 25 mg/mL, CBD 25 mg/mL (a "balanced" oil), or
• CBD 100 mg/mL, THC <2% (a CBD-dominant oil).

To turn that into a dose, you need the volume you take. If an oil is 25 mg/mL THC and your prescriber starts you on 0.1 mL, that's 2.5 mg of THC per dose. This is why the dropper or syringe markings matter as much as the label — the concentration plus the volume gives the actual dose.

For flower

Flower is labelled by percentage — the proportion of the dried weight that is each cannabinoid. For example THC 18%, CBD <1%. A higher percentage means a stronger product. With flower, dose also depends heavily on how much you use and the route (vaporising vs other), which makes precise dosing harder than with oils.

"Balanced," "THC-dominant," "CBD-dominant"

These shorthand terms describe the ratio. Balanced products have similar THC and CBD; THC-dominant lean intoxicating; CBD-dominant are non-intoxicating or close to it. The ratio shapes both the effect and the side-effect profile, which is why it's a key conversation with your prescriber.

Terpene and minor-cannabinoid data

Some products list terpene profiles or minor cannabinoids (CBG, CBN). This is useful extra detail — terpenes may influence how a product feels — but treat it as supplementary, not the headline. (See our terpenes explainer.) The THC/CBD figures are what drive dosing.

Batch and safety data

Beyond cannabinoids, a proper label and accompanying information should let you identify:

• Batch / lot number — ties the product to a specific tested batch (important for quality traceability and any recall).
• Expiry or use-by / best-before date — verified products are stability-tested for a defined shelf life; use within it. (See our storage guide.)
• Manufacturer / supplier and product name.
• The dispensing label from the pharmacy — your name, the prescriber, and the directions for use. This is the part that makes it your lawful, prescribed medicine.

Turning a label into a safe dose

1. Read the concentration (mg/mL for oil) or percentage (for flower).
2. Apply your prescriber's instructed volume/amount to get the actual mg.
3. Start at the low end and wait the full onset time before judging (slow for oils, slower for anything ingested).
4. Record it — dose, time, effect — to fine-tune with your prescriber.

Frequently asked questions

What does mg/mL mean on an oil? It's the concentration — milligrams of cannabinoid per millilitre. Multiply by the volume you take to get your dose in milligrams.

Why is flower in percentages but oil in mg/mL? Flower content is a proportion of dried weight (a percentage); oil is a measured concentration in liquid (mg/mL). Different formats, different conventions.

What's a "balanced" product? One with roughly equal THC and CBD. THC-dominant leans intoxicating; CBD-dominant is non-intoxicating or nearly so.

Why does the batch number matter? It links your product to a specific tested batch — useful for traceability, quality and any recall. Check the expiry too.

Sources

• Ministry of Health / Medicinal Cannabis Agency — product labelling and quality standard (accessed 2026-06-15)
• bpacnz — medicinal cannabis: dosing and product information (accessed 2026-06-15)
• Healthify NZ — cannabis-based products patient guide (accessed 2026-06-15)
• Medsafe — labelling of medicines (accessed 2026-06-15)

Information and education, not medical advice. Dose as your prescriber instructs. 18+.