Short answer

No recorded death from cannabis alone appears in the medical literature. THC has a wide gap between a normal dose and a lethal dose. A 10 mg edible holds 0.01 grams of THC. The estimated lethal dose for a 70 kg adult runs into the grams. People still overdose in the practical sense: they get sick enough for a hospital visit, and emergency department data shows those visits rising since legalization.

What the lethal dose numbers say

The oral LD50 for THC in rats is about 1,260 mg per kg of body weight. Scaled to a 70 kg adult, that points to a dose in the range of tens of grams of THC. Concentrates test at 60% to 90% THC, so one gram of wax holds 600 to 900 mg. Reaching tens of grams would take dozens of those units inside a short window. Nausea, sedation, and loss of coordination stop most people far below that point.

Symptoms of a cannabis overdose

Most symptoms peak within 2 to 4 hours and settle without treatment. THC does not slow breathing the way opioids do, which is the main reason a fatal overdose stays rare.

Why edibles cause most bad reactions

Edible THC passes through the liver and converts to 11-hydroxy-THC, a compound with stronger psychoactive effect than inhaled THC. Effects start 30 to 90 minutes after eating and peak at 2 to 4 hours. Many people eat a second serving before the first one hits. That second dose stacks on the first and drives the vomiting, panic, and hospital trips that poison control centers log.

When to seek medical help

  1. Chest pain or trouble breathing
  2. Fainting that repeats
  3. Seizure
  4. Vomiting that will not stop
  5. Confusion, or a person who cannot be woken
  6. Any reaction in a child

Call 911 for breathing problems or a seizure. For everything else, US poison control answers at 1-800-222-1222, 24 hours a day, free of charge.

Children face higher risk

A 5 mg edible is a light dose for an adult and a large dose for a 20 kg child. THC per kilogram of body weight climbs fast in small bodies. Symptoms in kids include sleepiness, unsteady walking, vomiting, and in serious cases slowed breathing. Pediatric exposure calls to poison control climbed after cannabis edibles entered the market. Store edibles in a locked box, not a kitchen drawer or a candy jar.

Cannabis hyperemesis syndrome

Daily use for years can trigger cycles of severe vomiting and belly pain. Hot showers or baths give short relief. The standard treatment is to stop cannabis. Repeated episodes can lead to dehydration and kidney strain.

Higher THC, higher risk

NIDA reports THC content in seized flower rose from under 4% in the mid-1990s to about 15% in 2018. Dabs and vape cartridges sit far higher. A single concentrate hit can deliver several times the THC of a 1990s joint, which is why dose labels matter more now than they did then.

Synthetic cannabinoids

K2 and Spice are not cannabis. These lab compounds bind the same receptors with greater strength. They have caused seizures, kidney damage, and deaths. The no-fatal-overdose rule does not cover them.

Dose rules that lower risk