Myths, Straight
Heard something about cannabis and not sure whether to believe it? Here are the common claims, each as a plain question, with a straight verdict, an evidence-strength badge, and a link to the full picture. No spin in either direction.
Is cannabis a gateway drug?
Verdict: mostly mythMost people who use cannabis never move on to harder drugs. There's a real statistical association, but association isn't cause. Shared risk factors, environment and simply having contact with an illegal market explain much of it. THINEvidence strength The "gateway" pattern is well documented as a correlation; robust evidence that cannabis causes progression to other drugs is thin, and most users never escalate. See the Volkow et al. (2014) NEJM review for the nuance.
The full answer →Is it safe because it's natural?
Verdict: falseNatural and safe aren't the same thing. Tobacco and deadly nightshade are natural too. Cannabis carries real risks that don't disappear because the plant grew in the ground, and today's high-potency product is a long way from "natural" in any meaningful sense.
Full picture in The Plant →Is cannabis less harmful than alcohol?
Verdict: partly trueFair on some measures: cannabis doesn't cause fatal overdose and its acute toxicity is lower. Misleading on others: it carries its own real risks around psychosis, dependence and driving. "Less harmful in some ways" is honest. "Harmless" is not. MIXEDEvidence strength Comparative harm rankings put alcohol above cannabis on several measures, but the two harm people differently, and cannabis is far from risk-free. Direct head-to-head evidence is limited.
Full picture in The Plant →Is cannabis addictive?
Verdict: yes, for someAround 1 in 11 users develops dependence, rising to about 1 in 6 among those who start as teenagers, and higher among daily users. It's less addictive than nicotine or alcohol, but "not addictive" is simply wrong. STRONGEvidence strength Roughly 9% of users develop dependence (~17% for adolescent-onset, higher for daily use). Source: Volkow et al. (2014), NEJM.
The full answer →Does cannabis cause schizophrenia?
Verdict: needs nuanceThere's a strong, dose-dependent link, especially with frequent, high-potency use, and the risk is concentrated in people already vulnerable. But most users never develop psychosis, and whether cannabis causes it or triggers it in the predisposed isn't fully settled. STRONGEvidence strength Strong association, dose-dependent; causation is complex. Di Forti et al. (2019), Lancet Psychiatry found daily high-potency use linked to ~5x the odds of first-episode psychosis; Marconi et al. (2016) shows a dose-response.
The full answer →Can you overdose on cannabis?
Verdict: misleading either wayTrue that fatal overdose from cannabis alone is vanishingly rare. But "no fatal overdose" doesn't mean "no risk." Greening out, acute anxiety and paranoia, accidents from impairment, and the longer-term risks are all real.
Full picture in The Plant →Is today's cannabis stronger than it used to be?
Verdict: trueAverage THC has climbed substantially over recent decades, while CBD, which appears to temper some of THC's effects, has all but vanished from street cannabis. The stuff on sale now really is a different product from the 1980s. STRONGEvidence strength UK seizures average ~14% THC with negligible CBD (Potter et al., 2018); potency has risen worldwide (Bath, 2020).
Full picture in The Plant →Does CBD get you high?
Verdict: falseCBD is the compound in cannabis that doesn't intoxicate you. On its own it produces no high, which is exactly why it can be sold legally in shops while THC can't. People conflate the two because they come from the same plant, but they behave very differently. STRONGEvidence strength CBD is non-intoxicating; it doesn't produce the euphoria or impairment THC does. This is well established and is the basis for CBD's separate legal status in the UK.
Full picture on the CBD page →Do indica and sativa reliably predict the effect?
Verdict: mostly mythIt's a neat story, but the indica/sativa label is a poor guide to how a given cannabis will actually make you feel. The effect is driven far more by the specific mix of cannabinoids and terpenes, and by dose, setting and the person, than by which category a seller has slapped on it. On the illegal market, where nothing's tested, the label is little more than branding. MIXEDEvidence strength The "indica = relaxing / sativa = uplifting" split doesn't map reliably onto chemical composition or reported effects; the "strain = specific effect" marketing goes well beyond what the evidence supports. See the terpene / "entourage effect" note in What's In It.
Full picture in The Plant →Will a detox drink beat a drug test?
Verdict: mostly mythCannabis metabolites are stored in fat and released slowly, and no drink flushes them out on demand. Most "detox" products work by diluting your urine for a few hours, which labs increasingly screen for, rather than actually clearing anything. They're unreliable, and for a frequent user the only dependable answer is time. THINEvidence strength "Detox" kits mainly dilute or mask rather than remove fat-stored THC metabolites; results are inconsistent and dilution is itself detectable. Detection windows depend on how heavily you've used, not on a product.
Full picture in Higher Stakes →Is cannabis basically legal now?
Verdict: falseIt isn't. Recreational cannabis is still a Class B controlled drug in the UK, and possession and supply carry real penalties. Two things fuel the confusion: prescribed medical cannabis became legal in 2018 (a narrow, specialist-only route), and legal CBD is sold everywhere. Neither makes recreational use legal (GOV.UK).
The full answer →Does cannabis cure cancer?
Verdict: false, and it mattersThis one does real harm. Some cannabinoids kill or slow cancer cells in the lab and in animals, but that has never translated into evidence that cannabis or CBD cures cancer in people. Treating it as a cure can lead someone to delay or refuse treatment that would actually help. STRONGEvidence strength There is no good evidence that cannabis or cannabis oil cures cancer in humans. Laboratory signals have not been borne out in clinical trials. Source: Cancer Research UK.
Full picture in Medical cannabis →Is driving high safer than driving drunk?
Verdict: misleadingCannabis impairs the skills driving needs, like reaction time, attention and lane control, and using before driving raises your crash risk. It may impair less dramatically than a skinful of alcohol, but "less bad than the worst case" isn't "safe." It's still illegal under the per-se limit, and mixing the two is worse than either alone. STRONGEvidence strength There is substantial evidence that cannabis use before driving increases the risk of a motor-vehicle crash; combining cannabis with alcohol impairs driving more than either on its own. See the National Academies (2017) review, and the UK law in The Law.
Full picture in The Law →Want to test yourself instead of just reading? The Myth or Fact? quiz runs you through these same claims one at a time.