Table 1 Adverse events associated with delta-8-THC reported by delta-8-THC users on Reddit forum r/Delta8 by MedDRA System Organ Class

Psychiatric disorders

Abnormal dreams, Agitation, Anxiety, Apathy, Autoscopy^a, Bruxism^a, Delusion, Dependence^a, Depersonalisation/derealisation disorder, Depressed mood^a, Depression, Derealisation^a, Disorientation, Dissociation, Dysphemia^a, Emotional poverty^a, Fear, Hallucination, Hallucination visual, Hallucinations mixed, Illusion, Insomnia, Irritability, Laziness^a, Libido increased^a, Mood swings, Negative thoughts, Nervousness, Nightmare^a, Panic attack, Panic reaction, Paranoia, Poor quality sleep, Post-traumatic stress disorder, Sleep attacks^a, Tachyphrenia, Time perception altered

"I'm no lightweight, but I got so high on Delta8 that I thought I was going to die. I called 911 and on the way to the ER they told me I might be having a panic attack." (PTs: Anxiety, Panic Attack)

41.2% (95% CI: 35.8–46.3)

Respiratory, thoracic and mediastinal disorders

Asthma^a, Choking sensation, Cough, Dry throat^a, Dyspnoea, Epistaxis, Haemoptysis^a, Nasal discomfort^a, Oropharyngeal discomfort^a, Oropharyngeal pain, Painful respiration^a, Pharyngeal swelling^a, Pneumonitis^a, Productive cough^a, Pulmonary pain^a, Respiratory tract irritation, Rhinalgia^a, Rhinorrhoea^a, Sinus pain^a, Sneezing^a, Sputum discoloured^a, Throat irritation^a, Throat tightness

“It began to hurt to breath, my lungs were hurting, and my throat was tight. I went to the ER for the pain, it was that bad.” (PTs: Painful respiration, Pulmonary pain, Throat tightness)

29.3% (95% CI: 25.1–34.0)

Nervous system disorders

Ageusia^a, Altered state of consciousness, Amnesia, Balance disorder, Burning sensation, Disturbance in attention, Dizziness, Dysarthria, Formication, Head discomfort^a, Headache, Hepatic encephalopathy^a, Hypoaesthesia, Loss of consciousness, Neuralgia^a, Neurological symptom^a, Non-24-h sleep–wake disorder^a, Paraesthesia, Paralysis, Presyncope, Psychomotor hyperactivity, Sedation, Seizure, Sensory disturbance, Somnolence, Tremor

“The high hit me all at once like a semi-truck. I was paralyzed and my legs were shaking uncontrollably‚ then I had a full on seizure which was later confirmed by a doctor.” (PTs: Paralysis, Tremor, Seizure)

23.3% (95% CI: 18.5–27.5)

General disorders and administration site conditions

Axillary pain^a, Chest discomfort, Chest pain, Chills, Drug withdrawal syndrome, Energy increased^a, Fatigue, Feeling abnormal, Feeling hot, Feeling jittery, Hangover^a, Hunger, Ill-defined disorder^a, Pain, Pyrexia, Secretion discharge^a, Thirst, Thirst decreased^a, Unevaluable event, Withdrawal syndrome

"I tried to quit d8 cold turkey but beware of these withdrawals. I relapsed after nine days because of how bad it was." (PTs: Drug withdrawal syndrome)

22.1% (95% CI: 17.9–26.6)

Gastrointestinal disorders

Abdominal discomfort, Abdominal distension^a, Abdominal pain, Abdominal pain upper, Constipation, Diarrhoea, Dry mouth, Flatulence^a, Gastrooesophageal reflux disease, Intra-abdominal fluid collection^a, Nausea, Odynophagia^a, Salivary hypersecretion^a, Swollen tongue, Tongue discomfort^a, Tooth deposit^a, Vomiting

“I’ve been having some bad stomach pain, dry mouth, and diarrhoea lately the last few times I've used d8." (PTs: Abdominal pain, dry mouth, diarrhoea)

17.0% (95% CI: 12.8–21.2)

Injury, poisoning and procedural complications

Accidental overdose

“How is this stuff legal? I'm so high right now and I've been high for the last 3 days since I first tried the edibles. I accidentally took way too much.” (PT: Accidental overdose)

8.7% (95% CI: 5.7–11.9)

Investigations

Ammonia increased^a, Blood pressure increased, Heart rate increased, Weight increased^a

"My watch told me my heart rate was at 162 while I was sitting down! My heart felt as if it was beating out of my chest." (PT: Heart rate increased)

7.5% (95% CI: 4.8–10.1)

Eye disorders

Asthenopia^a, Blepharospasm^a, Dry eye^a, Eye irritation, Eye pain^a, Eyelid ptosis^a, Metamorphopsia^a, Ocular hyperaemia, Photophobia^a, Photopsia^a, Vision blurred, Visual impairment

“It was awful, my eyes began to hurt bad, the pain felt someone was pouring acid in my eyes. Then they felt dry for days.“ (PTs: Eye pain, Dry Eye)

6.0% (95% CI: 3.3–8.7)

Metabolism and nutrition disorders

Abnormal loss of weight^a, Appetite disorder^a, Decreased appetite, Dehydration, Food craving^a, Increased appetite^a

"When I'm on delta-8, I go days without food and feel completely normal as long as I'm high still." (PT: Decreased Appettite)

4.5% (95% CI: 2.7–6.6)

Skin and subcutaneous tissue disorders

Acne^a, Cold sweat, Hyperhidrosis, Night sweats, Piloerection^a, Rash, Rash erythematous^a, Urticaria

"I was getting these cold sweats and goose bumps all over my body." (PTs: Cold sweat, Piloerection)

3.3% (95% CI: 1.5–5.1)

Musculoskeletal and connective tissue disorders

Muscle spasms, Muscle twitching, Pain in extremity^a

"Both of my entire legs cramped up multiple times during my trip on the edibles, it was extremely painful." (PTs: Muscle spasms, Pain in extremity)

2.4% (95% CI: 0.9–4.2)

Ear and labyrinth disorders

Hyperacusis^a, Tinnitus, Vertigo

"I couldn't shake the vertigo, the room was spinning so much. It was not enjoyable at all." (PT: Vertigo)

2.1% (95% CI: 0.9–3.9)

Vascular disorders

Hypertension, Shock, Vascular pain^a

"I had a really bad reaction to delta 8, I've been feeling pain in my veins and arteries for the past week." (PT: Vascular pain)

1.2% (95% CI: 0.3–2.7)

Hepatobiliary disorders

Hepatomegaly^a, Perihepatic discomfort^a

“The ER did CT scans and they found was an enlarged liver which the Dr. said could be due to the d8 use.” (PT: Hepatomegaly)

0.6% (95% CI: 0.0–1.5)

Cardiac disorders

Palpitations

"Had a gummy last night and woke up with heart palipitations. Waiting to hear back from my Doctor on what to do." (PT: Palpitations)

0.6% (95% CI: 0.0–1.5)

Immune system disorders

Hypersensitivity

"Right after vaping it felt like I was having an allergic reaction." (PT: Hypersensitivity)

0.3% (95% CI: 0.0–0.9)

Infections and infestations

Sinusitis

"Vaped 2 weeks ago and have had a sinus infection and sinus pain since then.” (PT: Sinustis)

0.3% (95% CI: 0.0–0.9)

Renal and urinary disorders

Urinary retention^a

"I felt like I needed to urinate but when I tried to go, I couldn't go at all." (PT: Urinary Retention)

0.3% (95% CI: 0.0–0.9)