Training 04 · The evidence

Tell hype from help.

The cannabis aisle is loud with claims. This is the quiet version: what the research actually shows, in plain language, each one tagged for how strong — or how shaky — the evidence really is.

superpower: a working hype detector ✺
How to read the tags

Not all "studies show" are equal

A single mouse study and a thousand-person clinical trial both get called "research." We grade every claim on one honest scale — strongest evidence first:

Solid Promising Mixed Shaky Myth
Solid = strong human trials. Promising = real signal, more needed. Mixed = it depends / studies disagree. Shaky = thin, small, or mostly anecdote. Myth = popular belief the data does not support.
The shelf

What the research actually says

Tap any claim to open the honest version. Filter by how much you can lean on it.

Featured white paper

The indica/sativa myth

The most repeated idea in cannabis — and the one the science most clearly contradicts. Here's the whole story.

White paper · 6 min read

Why "indica" and "sativa" can't tell you how you'll feel

"Indica for the couch, sativa for the day" is the first thing most people learn about cannabis. It is also, as a predictor of effects, essentially folklore.

Where the story came from

The words began as botany, not pharmacology. In the 1700s, "indica" described shorter, broad-leaf plants from South Asia; "sativa" the taller, narrow-leaf plants from equatorial regions. Decades of cannabis culture then welded consumer effects onto those plant shapes — indica became "in-da-couch," sativa became "energizing." The leaf shape and the feeling have no necessary connection.

What 90,000 samples revealed

In 2022, researchers ran the largest chemical analysis of commercial cannabis ever done — nearly 90,000 samples across six U.S. states. When they sorted products by their actual chemistry, three natural terpene families appeared. None of them lined up with the indica / sativa / hybrid labels on the jars.

"A sample labelled Indica will have an indistinguishable terpene composition from samples labelled Sativa or hybrid."

— Smith, Vergara, Keegan & Jikomes, PLOS ONE (2022). Read the study

Interactive · label vs. chemistry

Six products as a shelf would label them. Now reveal what's actually inside:

The labels don't even sort the chemistry

Plot real samples by their dominant terpenes and they fall into three clusters. Color each dot by its label and the colors scatter everywhere — there is no "indica corner." Watch:

labeled Indica labeled Sativa labeled Hybrid
Three chemistry clusters · labels scattered at random across all of them

What actually predicts the effect

Not the label — the chemovar: the specific mix of cannabinoids and terpenes. The two levers that matter most are the THC:CBD ratio (how intoxicating) and the dominant terpene (the character). Even genetics back this up — studies find "indica" strains are often more genetically similar to "sativas" than to each other, and two jars of the same famous strain name can be chemically unrelated.

Step 1

Chemotype

Type I = THC-dominant. Type II = balanced THC:CBD. Type III = CBD-dominant. This sets intensity.

Step 2

Dominant terpene

The biggest terpene on the lab report (COA) hints at character — myrcene, limonene, pinene, terpinolene, caryophyllene.

Step 3

Your own log

Track what a given chemovar actually did for you. Your body is the only validated instrument.

One honest caveat

Don't trade one oversimplification for another. The terpene-to-effect link (the "entourage effect") is biologically plausible but still mostly preclinical — promising, not proven. The strong, repeatable finding is the negative one: the indica/sativa label, on its own, does not predict your experience. Read the chemistry, start low, and keep notes.

Further reading: Russo, who called the labels "total nonsense," in Piomelli & Russo, Cannabis & Cannabinoid Research (2016); Elzinga et al. (2015) on cannabinoid/terpene chemotaxonomy.

Where this comes from

Sources

  1. Indica/sativa labels & chemistry — Smith CJ, Vergara D, Keegan B, Jikomes N. The phytochemical diversity of commercial Cannabis in the United States. PLOS ONE 2022;17(5):e0267498. journals.plos.org · pone.0267498
  2. "Total nonsense" — Piomelli D, Russo EB. The Cannabis sativa versus indica debate: an interview with Ethan Russo. Cannabis Cannabinoid Res 2016;1(1):44–46. pmc.ncbi.nlm.nih.gov/articles/PMC5576603
  3. Chemotaxonomy over labels — Elzinga S, et al. Cannabinoids and terpenes as chemotaxonomic markers in cannabis. Nat Prod Chem Res 2015.
  4. Terpene "entourage effect" (preclinical) — Christensen C, et al. Terpenes and the entourage effect: a systematic review. 2024. ncbi.nlm.nih.gov/pmc/articles/PMC11870048
  5. CBD for anxiety (inverted-U, ~300 mg) — Cannabinoid treatments for anxiety: a systematic review. Neurosci Biobehav Rev 2022;143:104941. pubmed.ncbi.nlm.nih.gov/36370842
  6. CBD & THC interaction — Freeman AM, et al. How does cannabidiol modulate the effects of THC? Neurosci Biobehav Rev 2019. sciencedirect.com · S0149763419305615
  7. High-potency THC & psychosis — Di Forti M, et al. (EU-GEI). Lancet Psychiatry 2019;6:427–436. thelancet.com · EU-GEI
  8. Chronic pain & other uses — National Academies of Sciences, Engineering, and Medicine. The Health Effects of Cannabis and Cannabinoids. 2017. ncbi.nlm.nih.gov/books/NBK423845
Educational, not medical advice. Evidence evolves — these summaries reflect the current weight of research, not certainty. For your own situation, talk with a clinician.