Medical Marijuana High for Chronic Illness: A Guide

Does Medical Marijuana Cause a High?

THC (delta-9-tetrahydrocannabinol) binds CB1 receptors in the brain and spinal cord. That binding produces the high. CBD does not bind CB1 the same way and does not produce a high on its own. A medical product with 20 mg THC will produce a high. A product with 0.5 mg THC and 20 mg CBD will not, for most people.

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Medical label does not mean low THC. Medical programs sell flower at 15% to 30% THC, the same range as adult-use flower.

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Dose Changes the Effect

Start low. 1 mg to 2.5 mg THC is a common starting dose for oral products. Wait 2 hours before taking more. A 10 mg oral dose produces a strong high in a person with no tolerance. The same 10 mg dose produces a mild effect in a daily user.

Best Medical Cannabis Strains for a Functional High

Route of Use

Inhaled

Smoke or vapor: effects start in 1 to 10 minutes, peak at 15 to 30 minutes, last 1 to 3 hours. About 10% to 25% of THC reaches the bloodstream.

Oral

Edibles, tinctures, and capsules: effects start in 30 to 120 minutes, peak at 2 to 4 hours, last 4 to 8 hours. Liver enzymes convert THC into 11-hydroxy-THC. That metabolite crosses the blood-brain barrier at a higher rate and produces a stronger effect than inhaled THC at the same milligram count.

Chronic Illness Conditions and Evidence

• Chronic pain: trial reviews show a small drop in pain scores. Effect sizes are modest.
• Chemotherapy nausea: FDA approved dronabinol (Marinol) and nabilone (Cesamet) for this use.
• Multiple sclerosis spasticity: nabiximols is approved in Canada and parts of Europe. It is not approved in the US.
• Severe childhood epilepsy: FDA approved Epidiolex, a CBD product, in 2018.
• Glaucoma, PTSD, Crohn's disease: evidence is limited. No FDA approvals exist for these uses.

Side Effects

Short-term effects include dizziness, dry mouth, red eyes, fast heart rate, memory trouble, anxiety, and sleepiness. Adults 65 and older have a higher risk of falls. A share of users develop cannabis use disorder. Rates differ by study. Heavy use is linked to bronchitis and, in some studies, to psychosis in people with a family history.

Tolerance and the High

Tolerance builds with daily use. The same dose produces less effect over weeks. A break of 2 to 4 weeks lowers tolerance. Cross-tolerance between cannabis and alcohol is not established.

Driving and Work

Do not drive after THC. Blood THC peaks within minutes of smoking and falls within hours. Oral THC stays in blood longer. Blood levels do not track impairment well, so a low test result does not prove a person is safe to drive.

Medical vs Adult Use in the US

As of 2024, 38 states and DC run medical cannabis programs. 24 states and DC allow adult use. Some states set higher possession limits and lower taxes for medical patients. Age rules differ. Some states allow medical patients under 21 with a caregiver.

What to Tell a Clinician

• Product name, THC mg, CBD mg, and route of use.
• Time of dose and time of symptoms.
• Other drugs, including blood thinners, benzodiazepines, and opioids.
• History of psychosis, heart disease, or falls.