Cannabis (Weed)

Δ9-Tetrahydrocannabinol (THC) / Cannabidiol (CBD)

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Cannabis is a flowering plant containing cannabinoids, primarily THC (psychoactive) and CBD (non-psychoactive). Used recreationally for relaxation, euphoria, and sensory enhancement. Increasingly legal and widely used in sexual contexts to enhance intimacy, sensation, and reduce inhibition.

How It Works

THC binds to CB1 receptors in the brain and nervous system, modulating neurotransmitter release (dopamine, serotonin, GABA, glutamate). Effects include altered perception, mood elevation, appetite stimulation, and pain modulation. CBD acts on different pathways with anti-anxiety and anti-inflammatory properties.

Legal Status

Federally Schedule I in the US, but legal for recreational use in 24+ states and DC. Legal in Canada, Uruguay, and parts of Europe. Medical use legal in most US states and many countries.

Dosage Guide (Inhalation / Oral)

LevelAmount (mg THC (or puffs for inhalation))
Threshold1-2 mg THC (1 puff)
Light2.5-5 mg THC (1-3 puffs)
Common5-15 mg THC
Strong15-30 mg THC
Heavy30+ mg THC

Note: Potency varies wildly. Modern flower is 15-30% THC vs 3-5% decades ago. Concentrates can be 60-90% THC. Edible doses should start at 2.5-5mg for beginners. Tolerance develops quickly with daily use.

Organ System Impacts

neurological — Moderate
THC alters neurotransmitter release throughout the brain. Impairs short-term memory, attention, and coordination while intoxicated. Adolescent use linked to altered brain development. In adults, most cognitive effects reverse with abstinence.
respiratory — High
Smoking damages airways — chronic bronchitis, increased mucus, airway inflammation. Vaping avoids combustion but carries risks from additives. No conclusive link to lung cancer from cannabis alone, but chronic smoking irritates lungs.
cardiovascular — Moderate
Acutely increases heart rate 20-50%. Mild blood pressure effects. Generally low risk for healthy individuals. May trigger events in those with pre-existing heart conditions.
gastrointestinal — Moderate
Appetite stimulation. Anti-nausea effects (therapeutic). Chronic heavy use can cause Cannabinoid Hyperemesis Syndrome — severe cyclic vomiting.
hepatic — Low
Metabolized by liver (CYP450 enzymes). Can interact with other medications metabolized by same pathway. Minimal direct hepatotoxicity.
ocular — Low
Reduces intraocular pressure (therapeutic for glaucoma). Causes red eyes from vasodilation. No significant damage.
renal — Low
Minimal direct kidney effects.
dermatological — Low
Minimal skin effects. Smoke exposure may contribute to premature aging with chronic heavy smoking.
hematological — Low
Minimal blood effects at recreational doses.
musculoskeletal — Low
Muscle relaxation. No significant musculoskeletal harm.

Effects

Desired Effects

Negative Effects

Rare but Serious

Drug Interactions

Alcohol — moderate

Alcohol increases THC blood levels. Combining intensifies impairment, nausea, and dizziness ('crossfading'). Dramatically increases risk of 'greening out'.

Action: Use one or the other, not both. If combining, use much less of each. Drink water. Have a safe place to sit/lie down.

Stimulants (Cocaine, Meth, MDMA) — moderate

Opposing effects on heart rate and blood pressure. Cannabis may mask stimulant warning signs. Increased cardiovascular strain.

Action: Be cautious of doses. Monitor heart rate. Cannabis may increase paranoia alongside stimulants.

Psychedelics (Mushrooms, LSD) — moderate

Cannabis significantly intensifies psychedelic effects. Can trigger anxiety, paranoia, or overwhelming experiences. Often enjoyable for experienced users but risky for novices.

Action: Only combine if experienced with both substances individually. Use very small amounts of cannabis. Avoid during peak of psychedelic experience.

CNS Depressants (GHB, Benzodiazepines, Opioids) — moderate

Additive sedation. Cannabis can increase nausea risk when combined with depressants.

Action: Reduce doses of both. Be especially careful with opioids — cannabis may mask warning signs of respiratory depression.

Detection Times

THC metabolites (THC-COOH) are fat-soluble and can persist in the body for weeks in regular users.

Urine

Standard immunoassay. Single use: 3-5 days. Regular use: 15-30+ days. Detection window: up to 30 days.

Blood

Active THC clears quickly but metabolites persist. Detection window: up to 7 days.

Hair

Hair follicle test can detect use over months. Detection window: up to 90 days.

Saliva

Detects recent use within hours to days. Detection window: up to 3 days.

Harm Reduction Tips

Withdrawal Symptoms

Severity: Low

Onset: 1-2 days after cessation. Peak: days 2-6. Resolution: most symptoms gone within 2-3 weeks. Sleep disruption and vivid dreams may persist 4-6 weeks.

Physical

Psychological

Emergency Information

Call 911 If:

What To Do

  1. Move to a calm, safe environment
  2. Reassure them: 'You're safe. This is temporary. It will pass.'
  3. Offer water and light snacks
  4. Try black pepper — chew or smell peppercorns (terpene beta-caryophyllene may reduce anxiety)
  5. If they can sleep, let them sleep it off
  6. For edible overdose: symptoms may last 6-12 hours. Ride it out in a safe place

What To Tell EMS

The patient consumed cannabis (THC). Route was [smoking/edibles/other]. Approximate dose if known. Duration since consumption. Main symptoms: [anxiety/vomiting/chest pain/psychosis]. No known lethal dose of THC in adults.

Seek Help If

Normal Discomfort

Harm reduction information only. This is not medical advice. If you are experiencing a medical emergency, call 911 immediately.