Facts / Evidence grade

Moderate evidence

15 facts graded moderate. Consistent human data with real limitations — direction is clear, magnitude is not.

Strong 38 Moderate 15 Limited 3 Mixed 6

"Indica relaxes, sativa energizes" does not survive the labChemical analyses repeatedly find that commercial indica/sativa labels poorly predict cannabinoid and terpene content — the actual drivers of effects. Researchers increasingly argue for chemovar (chemical variety) classification instead of folklore taxonomy.Moderate
Vaporizing flower avoids most combustion byproductsVaporizers heat cannabis below combustion, and studies show drastically reduced carbon monoxide and tar byproducts versus smoking, with similar THC delivery. "Reduced harm" is accurate; "harmless" is not — long-term data is thin, and vape liquids are a separate, riskier category.Moderate
Heavy adolescent use is linked to lasting cognitive effects — causality is still debatedLongitudinal studies associate heavy teen use with reduced memory, attention and IQ trajectories, with some effects persisting after stopping. Whether cannabis causes this or correlates with other factors is contested — but the developing brain (to ~25) is the agreed window of caution.Moderate
THC's memory effects in adults are mostly acute and reversibleTHC reliably impairs forming new short-term memories while high (the CB1-dense hippocampus at work). In adult occasional users, studies generally find function returns after abstinence — heavy long-term use shows subtler, more persistent patterns.Moderate
Cannabis lowers eye pressure — but too briefly to treat glaucomaTHC does reduce intraocular pressure, but only for 3–4 hours, requiring constant intoxicating doses to protect the optic nerve. Ophthalmology societies explicitly do not recommend it. A real effect, a poor medicine — the classic case of mechanism ≠ treatment.Moderate
CBD does not convert to THC in your stomachA widely shared claim that gastric acid converts CBD to psychoactive THC comes from simulated lab fluid, not human bodies. Human studies measuring THC and metabolites after oral CBD find no meaningful conversion. Epidiolex trials at high doses confirm: patients do not get high.Moderate
A common gene variant changes how strongly THC hits youPeople carry different versions of FAAH, the enzyme that breaks down anandamide. One common variant slows that breakdown, raising natural endocannabinoid levels — carriers show measurably different responses to THC, including lower dependence risk in several studies. Same joint, different brain.Moderate
The runner's high is largely endocannabinoid, not endorphinFor decades the post-run euphoria was blamed on endorphins — but endorphins barely cross the blood-brain barrier. Animal and human studies point instead to anandamide surging after sustained exercise. Your ECS, the same system THC hijacks, is the body's own reward for endurance.Moderate
Delta-8 THC is real — and mostly a legal loophole productDelta-8-THC is a naturally occurring isomer, roughly half to two-thirds as potent as delta-9. Plants make it in trace amounts, so commercial delta-8 is chemically converted from CBD. That conversion market grew in a regulatory gap, with little oversight of reaction byproducts — poison-control calls followed.Moderate
Vape temperature decides which terpenes you actually tasteTerpenes volatilize at different temperatures — myrcene and pinene low, linalool and caryophyllene higher — so the same flower delivers a different aromatic (and possibly experiential) profile at 170°C than at 210°C. The chemistry of boiling points is solid; claims of tailored effects remain ahead of the evidence.Moderate
A joint delivers a minority of its THC to youCombustion destroys a share of THC, sidestream smoke carries away more, and exhalation loses the rest — classic smoking-dynamic studies estimate roughly a fifth to a third reaches the smoker. Potency on the label is not potency in the blood.Moderate
Starting young and using strong: the psychosis risk pattern that keeps replicatingAcross cohort and case-control studies, adolescent initiation, daily use and high-potency products form a consistent risk gradient for later psychotic disorders. Whether cannabis causes the disorder or accelerates it in the vulnerable is still argued; the association itself is one of the most replicated in the field.Moderate
Edibles punch above their weight in emergency visitsColorado emergency-department data found edibles caused a disproportionate share of cannabis-related visits relative to their sales share — with more acute psychiatric and cardiovascular symptoms than inhaled use. The mechanism is familiar: delayed onset, impatient redosing, too much 11-hydroxy-THC.Moderate
Dogs and THC do not mix — vet visits rise with legalizationDogs have dense CB1 expression in the hindbrain, making them unusually sensitive to THC: ataxia, dribbling urine, low heart rate. Poison-control and veterinary studies show cases climbing sharply after legalization. Edibles left in bags are the classic culprit — and yes, that is what our PetFriendlyFoods app is for.Moderate
A cannabis mouth spray is an approved MS medicine in dozens of countriesNabiximols (Sativex), a 1:1 THC:CBD oromucosal spray, is approved across Europe, Canada and elsewhere for multiple-sclerosis spasticity that resists standard treatment. Trials show real but modest responder rates — it helps a subset of patients, not everyone.Moderate

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