High CBD medical cannabis strains carry CBD to THC ratios from 1:1 to 20:1. THC content in these cultivars runs from under 0.3% to about 5%. CBD content runs from about 5% to 20% of dried flower weight. Label values vary by grower, batch, and test lab.
High CBD Medical Cannabis: How to Choose Ratios, Products, and Lab-Tested Options
What counts as high CBD
Cannabis plants are grouped by chemotype. Chemotype I is THC dominant. Chemotype II carries CBD and THC at similar levels. Chemotype III is CBD dominant with THC below 1%. Chemotype III plants are the source of most high CBD medical strains.
The ratio matters more than the CBD percentage for some patients. A 20:1 strain produces little psychoactivity. A 1:1 strain may cause impairment and can show up on a drug screen.
Strains reported in lab panels
- Charlotte's Web. Reported at 17% to 20% CBD, with THC under 1% in some samples.
- ACDC. Reported at 15% to 20% CBD, with THC near 1% in some samples.
- Harlequin. Reported near 5% CBD and 2% THC, about a 5:2 ratio.
- Cannatonic. Reported at 6% to 17% CBD, with ratios from 1:1 to 2:1.
- Sour Tsunami. Reported near a 1:1 ratio.
- Ringo's Gift. Reported CBD above 15% with low THC.
- Remedy. Reported CBD above 10% with THC under 1%.
These numbers come from published lab panels and seed listings. They are not fixed. The same clone grown in two rooms can test at two values.
US legal limits
The 2018 Farm Bill sets hemp as cannabis with delta-9 THC at or below 0.3% on a dry weight basis. Hemp is legal at the federal level. Cannabis above 0.3% THC stays illegal under federal law. States with medical programs issue cards that permit higher THC products. Rules differ by state. Check state program rules before buying or growing.
Dose and onset
FDA approved one cannabis-derived drug, Epidiolex, for seizures linked to Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex. Trial doses reached 20 mg per kg per day. Oral CBD absorption is low, with studies reporting about 6% bioavailability. Onset runs 30 to 120 minutes by mouth and 1 to 10 minutes by inhalation. Effects last longer after oral use.
Lab tests to request
- Potency panel with CBD, THC, CBDA, and THCA values.
- Pesticide screen.
- Heavy metals screen.
- Residual solvents screen.
- Microbial and mycotoxin screen.
A certificate of analysis should list the lab name, sample date, batch number, and method. Numbers on a package with no matching batch report carry little weight.
Open questions
Long term safety data for inhaled cannabis is limited. CBD inhibits CYP2C19 and CYP3A4, so it can change blood levels of some drugs. High oral doses have raised liver enzymes in trials. The entourage effect, the claim that terpenes and minor cannabinoids change CBD action, has limited human evidence.