Table 3.

Adverse events by system organ class in the safety population

		Molnupiravir (n=90)	Placebo (n=90)	Total (n=180)
At least one adverse event		73 (81%)	68 (76%)	141 (78%)
Blood and lymphatic system disorders		1 (1%)	2 (2%)	3 (2%)
	Anaemia	0	1 (1%)	1 (1%)
	Left axillary painful lymph node with no swelling noted	0	1 (1%)	1 (1%)
	Lymphopenia	1 (1%)	0	1 (1%)
	Right axillary lymph node painless swelling	0	1 (1%)	1 (1%)
Cardiac disorders		5 (6%)	1 (1%)	6 (3%)
	Cardiac chest pain	2 (2%)	0	2 (1%)
	Chest tightness	2 (2%)	0	2 (1%)
	Palpitations	1 (1%)	1 (1%)	2 (1%)
	Sinus bradycardia	1 (1%)	0	1 (1%)
Ear and labyrinth disorders		3 (3%)	1 (1%)	4 (2%)
	Ear pain	2 (2%)	0	2 (1%)
	Ear and labyrinth disorder (itching left ear)	1 (1%)	0	1 (1%)
	Vertigo	0	1 (1%)	1 (1%)
Eye disorders		4 (4%)	6 (7%)	10 (6%)
	Blurred vision	2 (2%)	2 (2%)	4 (2%)
	Eye pain	0	1 (1%)	1 (1%)
	Erythema on right eyelid	0	1 (1%)	1 (1%)
	Eyes sensitive to light	1 (1%)	0	1 (1%)
	Itchy eyes	1 (1%)	0	1 (1%)
	Photophobia	0	1 (1%)	1 (1%)
	Watering eyes	0	2 (2%)	2 (1%)
Gastrointestinal disorders		27 (30%)	37 (41%)	64 (36%)
	Abdominal pain	6 (7%)	7 (8%)	13 (7%)
	Bloating	0	1 (1%)	1 (1%)
	Constipation	1 (1%)	0	1 (1%)
	Diarrhoea	9 (10%)	16 (18%)	25 (14%)
	Dry mouth	1 (1%)	1 (1%)	2 (1%)
	Dyspepsia	0	1 (1%)	1 (1%)
	Dysphagia	0	3 (3%)	3 (2%)
	Flatulence	1 (1%)	0	1 (1%)
	Gastro-oesophageal reflux disease	0	1 (1%)	1 (1%)
	Gingival pain	1 (1%)	0	1 (1%)
	Nausea	6 (7%)	14 (16%)	20 (11%)
	Abdominal cramping and loose stools	0	1 (1%)	1 (1%)
	Burning in throat	0	1 (1%)	1 (1%)
	Gallstone pancreatitis	0	1 (1%)	1 (1%)
	Indigestion	0	1 (1%)	1 (1%)
	Loose stools	1 (1%)	1 (1%)	2 (1%)
	Tongue pain	1 (1%)	0	1 (1%)
	Stomach pain	3 (3%)	3 (3%)	6 (3%)
	Vomiting	2 (2%)	9 (10%)	11 (6%)
General disorders and administration site conditions		10 (11%)	13 (14%)	23 (13%)
	Chills	2 (2%)	3 (3%)	5 (3%)
	Face oedema	0	1 (1%)	1 (1%)
	Fatigue	2 (2%)	2 (2%)	4 (2%)
	Fever	1 (1%)	1 (1%)	2 (1%)
	Influenza-like symptoms	0	1 (1%)	1 (1%)
	Non-cardiac chest pain	5 (6%)	5 (6%)	10 (6%)
Immune system disorders		2 (2%)	1 (1%)	3 (2%)
	Allergic reaction	0	1 (1%)	1 (1%)
	Exacerbation of allergic rhinitis	1 (1%)	0	1 (1%)
	Tonsillitis	1 (1%)	0	1 (1%)
Infections and infestations		4 (4%)	6 (7%)	10 (6%)
	Conjunctivitis	0	1 (1%)	1 (1%)
	Lung infection	0	2 (2%)	2 (1%)
	Cold sore	0	1 (1%)	1 (1%)
	Upper respiratory tract infection	1 (1%)	0	1 (1%)
	Otitis externa	1 (1%)	1 (1%)	2 (1%)
	Infective rhinitis	0	1 (1%)	1 (1%)
	Skin infection	1 (1%)	0	1 (1%)
	Tooth infection	1 (1%)	0	1 (1%)
	Urinary tract infection	0	1 (1%)	1 (1%)
Injury, poisoning, and procedural complications		2 (2%)	0	2 (1%)
	Fall	1 (1%)	0	1 (1%)
	Sunburn	1 (1%)	0	1 (1%)
Investigations		4 (4%)	4 (4%)	8 (4%)
	Increased alanine aminotransferase	2 (2%)	1 (1%)	3 (2%)
	Increased alkaline phosphatase	0	1 (1%)	1 (1%)
	Increased blood bilirubin	1 (1%)	1 (1%)	2 (1%)
	Increased creatinine	1 (1%)	0	1 (1%)
	Prolonged heart-rate corrected QT interval	0	1 (1%)	1 (1%)
	Increased γ-glutamyl transferase	1 (1%)	2 (2%)	3 (2%)
	Decreased neutrophil count	1 (1%)	1 (1%)	2 (1%)
Metabolism and nutrition disorders		3 (3%)	1 (1%)	4 (2%)
	Anorexia	1 (1%)	0	1 (1%)
	Hypocalcaemia	0	1 (1%)	1 (1%)
	Hypokalaemia	0	1 (1%)	1 (1%)
	Hypomagnesaemia	0	1 (1%)	1 (1%)
	Hypophosphataemia	1 (1%)	0	1 (1%)
	Loss of appetite	1 (1%)	0	1 (1%)
Musculoskeletal and connective tissue disorders		11 (12%)	12 (13%)	23 (13%)
	Arthralgia	1 (1%)	0	1 (1%)
	Arthritis	0	1 (1%)	1 (1%)
	Back pain	1 (1%)	1 (1%)	2 (1%)
	Chest wall pain	1 (1%)	1 (1%)	2 (1%)
	Flank pain	1 (1%)	0	1 (1%)
	Myalgia	2 (2%)	5 (6%)	7 (4%)
	Neck pain	1 (1%)	0	1 (1%)
	Body aches and pains	1 (1%)	0	1 (1%)
	Knee pain	1 (1%)	0	1 (1%)
	Left shoulder pain	0	1 (1%)	1 (1%)
	Lower back pain	1 (1%)	0	1 (1%)
	Reduced power to right thumb	0	1 (1%)	1 (1%)
	Right foot pain	1 (1%)	0	1 (1%)
	Pain in arms or legs	2 (2%)	2 (2%)	4 (2%)
Nervous system disorders		37 (41%)	34 (38%)	71 (39%)
	Anosmia	5 (6%)	5 (6%)	10 (6%)
	Dizziness	12 (13%)	2 (2%)	14 (8%)
	Dysgeusia	5 (6%)	2 (2%)	7 (4%)
	Headache	16 (18%)	19 (21%)	35 (19%)
	Hypersomnia	3 (3%)	0	3 (2%)
	Lethargy	0	1 (1%)	1 (1%)
	Ageusia	0	1 (1%)	1 (1%)
	Feeling light-headed and dizzy	0	1 (1%)	1 (1%)
	Feeling weakness in lower limbs	0	1 (1%)	1 (1%)
	Feeling hot	0	1 (1%)	1 (1%)
	Head congestion	0	2 (2%)	2 (1%)
	Light-headedness	0	1 (1%)	1 (1%)
	Loss of smell and loss of taste	1 (1%)	0	1 (1%)
	Numbness and dryness of third and fourth fingers on right hand	1 (1%)	0	1 (1%)
	Paresthesia	2 (2%)	2 (2%)	4 (2%)
	Presyncope	3 (3%)	0	3 (2%)
	Syncope	0	2 (2%)	2 (1%)
	Tremor	1 (1%)	1 (1%)	2 (1%)
Renal and urinary disorders		2 (2%)	0	2 (1%)
	Haematuria	1 (1%)	0	1 (1%)
	Cystitis	1 (1%)	0	1 (1%)
	Increased urinary frequency	1 (1%)	0	1 (1%)
Reproductive system and breast disorders		4 (4%)	3 (3%)	7 (4%)
	Menorrhoea	0	1 (1%)	1 (1%)
	Vaginal bleeding (menses)	0	1 (1%)	1 (1%)
	Other, specify	1 (1%)	0	1 (1%)
	Vaginal discharge	1 (1%)	1 (1%)	2 (1%)
	Vaginal haemorrhage	2 (2%)	0	2 (1%)
Respiratory, thoracic, and mediastinal disorders		29 (32%)	28 (31%)	57 (32%)
	Allergic rhinitis	1 (1%)	0	1 (1%)
	Cough	3 (3%)	7 (8%)	10 (6%)
	Dyspnoea	5 (6%)	4 (4%)	9 (5%)
	Hoarseness	0	1 (1%)	1 (1%)
	Nasal congestion	3 (3%)	3 (3%)	6 (3%)
	Chest congestion	2 (2%)	3 (3%)	5 (3%)
	Chest congestion or chest tightness	0	1 (1%)	1 (1%)
	Chest tightness	4 (4%)	4 (4%)	8 (4%)
	Chest tightness and congestion	1 (1%)	0	1 (1%)
	Dry cough	1 (1%)	0	1 (1%)
	Increased breathlessness and chest tightness	0	1 (1%)	1 (1%)
	Pneumonia	0	1 (1%)	1 (1%)
	Scratchy or itchy throat	0	1 (1%)	1 (1%)
	Scratchy, itchy throat	2 (2%)	0	2 (1%)
	Trouble breathing	0	1 (1%)	1 (1%)
	Wheeze on chest examination	1 (1%)	0	1 (1%)
	Pleuritic pain	1 (1%)	0	1 (1%)
	Productive cough	6 (7%)	5 (6%)	11 (6%)
	Rhinorrhoea	3 (3%)	0	3 (2%)
	Sinus pain	1 (1%)	2 (2%)	3 (2%)
	Sneezing	1 (1%)	4 (4%)	5 (3%)
	Sore throat	6 (7%)	6 (7%)	12 (7%)
Skin and subcutaneous tissue disorders		7 (8%)	8 (9%)	15 (8%)
	Hyperhidrosis	2 (2%)	3 (3%)	5 (3%)
	Itchy skin rash	1 (1%)	0	1 (1%)
	Leukonychia on fifth finger of right hand	1 (1%)	0	1 (1%)
	Nipple sensitivity	0	1 (1%)	1 (1%)
	Rosacea acne around chin (flare up)	0	1 (1%)	1 (1%)
	Skin blisters	1 (1%)	0	1 (1%)
	Skin rash	1 (1%)	1 (1%)	2 (1%)
	Erythematous rash on both cheeks and nose	0	1 (1%)	1 (1%)
	Photosensitivity	1 (1%)	0	1 (1%)
	Maculopapular rash	0	1 (1%)	1 (1%)
Vascular disorders		3 (3%)	0	3 (2%)
	Hot flushes	1 (1%)	0	1 (1%)
	Hypertension	2 (2%)	0	2 (1%)
Unclassified		4 (4%)	3 (3%)	7 (4%)
	Abdominal cramps	1 (1%)	0	1 (1%)
	Abdominal discomfort	0	1 (1%)	1 (1%)
	Blocked nose	0	1 (1%)	1 (1%)
	Chest tightness	2 (2%)	0	2 (1%)
	Coryzal symptoms	1 (1%)	0	1 (1%)
	Loss of sense of taste	1 (1%)	0	1 (1%)
	Loss of smell	0	1 (1%)	1 (1%)
	Loss of taste	0	1 (1%)	1 (1%)
	Muscular soreness over sternum	0	1 (1%)	1 (1%)
	Reduction in appetite	1 (1%)	0	1 (1%)
	Reduction in taste	1 (1%)	0	1 (1%)
	Vaginal thrush	0	1 (1%)	1 (1%)
	Viral gastroenteritis	0	1 (1%)	1 (1%)

Data are n (%). Within each system organ class, a participant can have more than one adverse event.