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Ritlecitinib Side Effects

The most commonly reported side effects of ritlecitinib include therapeutic product effect incomplete, condition aggravated, and off label use, based on 1,650 FDA adverse event reports from 2005 to 2025. 17.7% of reports found the drug to be ineffective.

Ritlecitinib side effects

Percentages show how often each reaction appears relative to total reports for ritlecitinib.

1
Drug Ineffective17.7%292
2
Therapeutic Product Effect Incomplete7.9%130
3
Condition Aggravated6.1%101
4
Off Label Use6.1%101
5
Headache4.6%76
6
Diarrhoea3.5%57
7
Alopecia3.3%54
8
Product Dose Omission Issue2.9%48
9
Pruritus2.7%44
10
Urticaria2.5%42
11
Acne2.5%41
12
Fatigue2.3%38
13
Rash2.2%36
14
Nausea2.1%34
15
Blood Creatine Phosphokinase Increased1.9%31

These are voluntary reports and do not establish that ritlecitinib caused these reactions.

Report severity

16.8%Serious277 reports
3.8%Hospitalizations63 reports
0.1%Fatal2 reports

Seriousness is determined by the reporter, not by OpenClaim.

Ritlecitinib drug interactions

Other drugs that appear in adverse event reports alongside ritlecitinib. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Baricitinib0.8%13
2
Dupilumab0.7%11
3
Tofacitinib0.5%9
4
Minoxidil0.5%8
5
Clindamycin0.2%4
6
Amoxicillin0.2%3
7
Clavulanate-potassium0.2%3
8
Abrocitinib0.2%3
9
Acetaminophen0.2%3
10
Oxycodone0.2%3
11
Sulfamethoxazole0.1%2
12
Diphenhydramine0.1%2
13
Infliximab0.1%2
14
Norethindrone0.1%2
15
Ergocalciferol0.1%2

Taken alongside

1
Minoxidil3.3%54
2
Ergocalciferol2.3%38
3
Levothyroxine-sodium2.2%36
4
Triamcinolone1.2%19
5
Omeprazole0.9%15
6
Albuterol0.9%15
7
Cetirizine-hydrochloride0.8%14
8
Ascorbic-acid0.8%13
9
Clobetasol-propionate0.8%13
10
Montelukast-sodium0.7%12
11
Baricitinib0.7%12
12
Fluticasone0.7%12
13
Fexofenadine-hydrochloride0.6%10
14
Atorvastatin-calcium0.6%10
15
Metformin0.6%10

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports ritlecitinib side effects

58.2% of ritlecitinib adverse event reports involve female patients and 30.9% involve male patients. The largest age group is adult at 61%. These figures reflect who reports side effects, not underlying risk.

Sex

Female58.2%
Male30.9%
Unknown10.9%

Age group

< 20.0%
2–111.2%
12–1729.9%
18–6460.9%
65+8.0%

What is ritlecitinib used for

Conditions and purposes for which patients were taking ritlecitinib when the adverse event was reported.

AlopeciaAlopecia AreataAlopecia ScarringAlopecia TotalisAlopecia UniversalisAndrogenetic AlopeciaAutoimmune DisorderCholelithiasisChronic DiseaseDermatitisDermatitis AtopicDiffuse AlopeciaEczemaFollicular DisorderFolliculitis

Showing 15 of 36 indications

Ritlecitinib brand names and reporting trend

Ritlecitinib is sold under the brand name Litfulo.

Brand names

Litfulo124

Quarterly reports (20052025)

20102025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking ritlecitinib with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.