How to Read a Cannabis Product Label: THC, CBD & Terpenes Explained
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A cannabis product label tells you THC and CBD content (as a percentage or mg per serving), the terpene profile, and lab-verified purity data. In South Africa, SAHPRA requires accurate cannabinoid labelling and batch testing for microbial and heavy-metal contaminants, so a compliant label is your main tool for judging potency and safety before you buy.
New to cannabis terms altogether? Start with our terminology guide. This article focuses specifically on decoding the numbers and testing data printed on a product's label or certificate of analysis.
What South African Cannabis and CBD Product Labels Are Required to Show
SAHPRA (the South African Health Products Regulatory Authority) requires cannabinoid products to carry clear, accurate labelling that reflects laboratory-verified content rather than a grower's estimate. In practice, a compliant label or accompanying certificate of analysis should show cannabinoid content (CBD, CBDA, THC, THCA, and often CBG and CBN), terpene content where tested, and confirmation that the batch has passed contaminant testing. Labels are not permitted to make unproven health or medical claims, and any health claim must be supported by evidence and, for anything beyond low-risk general wellness claims, pre-approved by SAHPRA.
For hemp-derived CBD specifically, South African rules cap THC at 0.001% (10 parts per million) and recommend a maximum daily dose of 20mg of CBD, figures that should be checkable against the label or certificate of analysis for any product you buy, including our CBD products range. Hemp itself is legally defined as cannabis with no more than 2% THC in the leaves and flowering heads.
THC Percentage: What It Actually Tells You
THC percentage measures how much delta-9 THC, the primary psychoactive compound, makes up the dry weight of the product. A flower labelled 22% THC means 22% of its dry weight is THC. This number is a genuine potency indicator, but it is not a complete description of the experience a product will produce, that depends heavily on the full cannabinoid and terpene profile, plus dose, method, and your own physiology. We cover that distinction in detail in Indica vs Sativa vs Hybrid: What Actually Determines the Effects, since a high THC number on its own doesn't tell you whether an experience will feel energising or sedating.
Higher THC Isn't Automatically Better
A very high-THC product can simply mean a more intense, harder-to-control experience, not a more enjoyable one. A moderate-THC product with a well-documented terpene profile often produces a more predictable, more pleasant result than the highest number on the shelf.
CBD Content: Percentage vs Milligrams
CBD is usually labelled one of two ways: as a percentage of dry weight (common on flower) or as milligrams per serving or per bottle (common on oils, tinctures and edibles). Milligram dosing is generally more useful for consistent, repeatable dosing since it tells you exactly how much active compound you're taking per use, rather than requiring you to estimate from a percentage and a serving size. When you're shopping specifically for CBD's calming, non-intoxicating effects without THC's variability, our CBD products list mg content per serving so you can dose consistently.
THC:CBD Ratio: Why the Balance Matters
A product's THC:CBD ratio tells you how psychoactive versus how calming it is likely to feel, independent of the raw THC number. A 1:1 ratio product tends to feel noticeably less intense than a THC-only product at the same THC percentage, because CBD moderates some of THC's psychoactive impact. If you want a strong, clearly psychoactive experience, a THC-dominant ratio is what to look for; if you want a milder, more functional effect, a higher-CBD ratio is usually the better fit.
Total Active Cannabinoids (TAC): More Complete Than THC Alone
Total Active Cannabinoids (TAC) combines the contribution of multiple cannabinoids, typically THC, THCA, CBD, CBDA, CBG and CBN, into one figure, rather than reporting THC in isolation. Because THCA converts to THC when heated (a process called decarboxylation), a product's TAC after accounting for that conversion is often a more accurate real-world potency figure than the raw "THC%" line alone. If a certificate of analysis lists TAC, it's worth checking alongside the headline THC number rather than instead of it.
Terpenes on the Label: What They Are and Why They're Listed
Terpenes are the aromatic compounds responsible for a strain's smell and flavour, and many labels or certificates of analysis list the top two or three terpenes present, often with percentages. The most commonly listed terpenes and their typical associations include:
- Myrcene: Earthy, musky, commonly associated with relaxing, sedating effects
- Limonene: Citrusy, associated with mood elevation and reduced anxiety
- Pinene: Pine-scented, associated with alertness and mental clarity
- Linalool: Floral, associated with calming, anti-anxiety effects
- Caryophyllene: Peppery, notable as the only terpene known to bind directly to a cannabinoid receptor (CB2)
A higher total terpene percentage doesn't automatically mean a "stronger" product, but it typically signals a fuller aroma and flavour, and potentially a more nuanced effect. For a full breakdown of how terpene and cannabinoid profiles combine to actually shape a strain's effects, rather than relying on the indica/sativa label, see our guide Indica vs Sativa vs Hybrid: What Actually Determines the Effects.
The Entourage Effect: What the Science Currently Says
The "entourage effect" is the theory that terpenes and cannabinoids work together to shape effects, rather than each compound acting alone. The evidence here is genuinely mixed. Some behavioural studies in mice found that terpenes like linalool and beta-pinene produced cannabinoid-like effects that were additive with cannabinoid activity, while other receptor-binding research found little to no direct interaction between most terpenes and the body's CB1 or CB2 cannabinoid receptors, with beta-caryophyllene as a partial exception. A comprehensive 2024 review of entourage effect research concluded that while exploratory evidence is promising, no reliable synergy has yet been confirmed at the receptor level, and more clinical trials are needed. Treat terpene listings as useful, evidence-backed context, not a guaranteed effect formula.
Batch Numbers, Certificates of Analysis, and Expiry Dates: The Safety Side of the Label
Potency numbers are only half the picture. SAHPRA requires every batch of a regulated cannabinoid product to be tested for microbiological contaminants (including yeast, mould and specific pathogens), heavy metals (mercury, lead, arsenic, cadmium), and pesticide residues, with results tied to that specific batch or lot number. When you're checking a label:
- Batch or lot number: Lets you match the physical product to its specific certificate of analysis, not a generic one for the product line.
- Certificate of analysis (COA): Should be available from a reputable seller, either printed, on a QR code, or on request, and should confirm contaminant testing passed.
- Expiry or best-before date: Cannabinoid content and terpene aroma both degrade over time, older stock is not necessarily unsafe, but it will likely test lower in potency than the original label.
Cannabis Label Terms at a Glance
| Label Term | What It Measures | Why It Matters |
|---|---|---|
| THC % | Psychoactive potency by dry weight | Signals intensity potential, not the type of experience |
| CBD (% or mg) | Non-intoxicating cannabinoid content | Moderates THC and enables consistent, non-psychoactive dosing |
| THC:CBD Ratio | Balance between the two main cannabinoids | Predicts how psychoactive vs calming a product will feel |
| TAC | Combined active cannabinoid content | Gives a fuller potency picture than THC alone |
| Terpene % | Aromatic compound content | Shapes flavour, aroma, and potentially effect nuance |
| Batch/Lot Number | Product traceability | Confirms lab results match this specific batch, not a generic average |
What If You're Growing Your Own?
Homegrown cannabis doesn't come with a lab-tested label, so genetics and growing conditions become your main source of information instead. If you're cultivating from our sativa-dominant, indica-dominant, or hybrid seed collections, each listing includes known genetic lineage as a reference point, though actual cannabinoid and terpene content will still depend on your growing conditions. Skyline Smoke Company sells seeds strictly for novelty and germination-reference purposes, not for commercial cultivation, see our Seed Bank Germination Policy for the full framing under South African law.
Quick Label-Reading Checklist
- Check THC% and CBD (% or mg) first for baseline potency
- Look at the THC:CBD ratio to gauge how psychoactive vs calming the product will feel
- If listed, check TAC for a fuller potency picture than THC alone
- Review the terpene profile for flavour and possible effect nuance
- Confirm there's a batch/lot number and, ideally, an accessible certificate of analysis
- Check the expiry or best-before date before buying, especially for flower
Frequently Asked Questions
What does THC percentage on a label actually mean?
It's the proportion of the product's dry weight made up of delta-9 THC, the primary psychoactive cannabinoid. A product labelled 22% THC has 22% of its dry weight as THC.
Is a higher THC percentage always stronger or better?
Higher THC generally does mean more potential psychoactivity, but it doesn't determine the type of experience or guarantee a better one. Terpene profile, other cannabinoids, dose, and method all shape the actual experience.
What's the difference between CBD listed as a percentage and CBD listed in milligrams?
Percentage reflects proportion of dry weight, common on flower. Milligrams per serving reflect an exact dose, common on oils and edibles, and are generally easier to use for consistent dosing.
What is TAC and why does it matter more than THC alone?
TAC (Total Active Cannabinoids) combines multiple cannabinoids, including THC after accounting for THCA conversion, into one figure. It often gives a more accurate real-world potency picture than the THC% line by itself.
Do terpenes on a label really change how a product feels?
The evidence is mixed. Some research shows certain terpenes can enhance cannabinoid activity, while other studies find little direct receptor interaction for most terpenes. Terpene listings are useful, evidence-backed context rather than a guaranteed effect formula.
What lab testing must South African cannabis and CBD products undergo?
SAHPRA requires testing for cannabinoid content, microbiological contaminants, heavy metals, and pesticide residues, with results tied to a specific batch or lot number.
What should I check besides the THC and CBD numbers?
Look for a batch/lot number, an accessible certificate of analysis confirming contaminant testing, and an expiry or best-before date, since potency and aroma both degrade over time.
Final Thoughts
A cannabis or CBD label is a genuine safety and potency tool once you know what each figure means, THC%, CBD content, ratio, TAC, terpene profile, and the batch-level testing data behind them. Browse our lab-considered CBD products range, or go deeper on what actually drives a strain's effects in Indica vs Sativa vs Hybrid. Have questions about a specific product's label? WhatsApp us on 0718837026 or visit us at 2 Yaron Avenue, Glenanda, Johannesburg.
