What the label lists and what reports show
Ribociclib side effects
Ribociclib's FDA label: “In patients with early breast cancer, the most common (incidence ≥ 20%) adverse reactions, including laboratory abnormalities, are lymphocytes decreased, leukocytes decreased, neutrophils decreased, hemoglobin decreased, alanine aminotransferase increased …” FAERS holds 31,378 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is neutropenia (4,093 reports).
- No generic listed
Check it at the source: the ribociclib FDA label on DailyMed (effective July 1, 2026, Novartis Pharmaceuticals Corporation); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of KISQALI?KISQALI may cause serious side effects, including: See "What is the most important information I should know about KISQALI?" The most common side effects of KISQALI in people with early breast cancer include: • decreased white blood cell counts • decreased red blood cell counts • increased liver function tests • infections • increased kidney function test • decreased platelet counts • nausea • headache • tiredness The most common side effects of KISQALI in people with advanced or metastatic breast cancer include: • decreased white blood cell counts • decreased red blood cell counts • increased liver function tests • infections • nausea • increased kidney function test • tiredness • decreased platelet counts • diarrhea • vomiting • headache • constipation • hair loss • cough • rash • back pain • low blood sugar level KISQALI may cause fertility problems in males, which may affect your ability to father a child. […]
Source: FDA drug label, Novartis Pharmaceuticals Corporation, effective July 1, 2026 (SPL set aaeaef94-f3f5-4367-8ea2-b181d7be2da8), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsIn patients with early breast cancer, the most common (incidence ≥ 20%) adverse reactions, including laboratory abnormalities, are lymphocytes decreased, leukocytes decreased, neutrophils decreased, hemoglobin decreased, alanine aminotransferase increased, aspartate aminotransferase increased, infections, creatinine increased, platelets decreased, headache, nausea, and fatigue.
Table 12: Adverse Reactions (≥ 10% and ≥ 2% Higher Than Placebo Arm) in MONALEESA-2
| Reaction | All Grades (%) | Grade 3 or 4 (%) | All Grades (%) | Grade 3 or 4 (%) |
|---|---|---|---|---|
| Nausea 1 | 52 | 2.4 | 29 | 0.6 |
| Diarrhea 1 | 35 | 1.2 | 22 | 0.9 |
| Vomiting 1 | 29 | 3.6 | 16 | 0.9 |
| Constipation 1 | 25 | 1.2 | 19 | 0 |
| Stomatitis 1 | 12 | 0.3 | 7 | 0 |
| Abdominal pain 1 | 11 | 1.2 | 8 | 0 |
| Fatigue | 37 | 2.4 | 30 | 0.9 |
| Pyrexia 1 | 13 | 0.3 | 6 | 0 |
| Peripheral edema 1 | 12 | 0 | 10 | 0 |
| Alopecia 1 | 33 | 0 | 16 | 0 |
| Rash 1 | 17 | 0.6 | 8 | 0 |
| Pruritus 1 | 14 | 0.6 | 6 | 0 |
| Headache 1 | 22 | 0.3 | 19 | 0.3 |
| Insomnia 1 | 12 | 0.3 | 9 | 0 |
| Back pain 1 | 20 | 2.1 | 18 | 0.3 |
| Decreased appetite 1 | 19 | 1.5 | 15 | 0.3 |
| Dyspnea 1 | 12 | 1.2 | 9 | 0.6 |
| Urinary tract infections 1 | 11 | 0.6 | 8 | 0 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following adverse reactions are discussed in greater detail in other sections of the labeling: Interstitial Lung Disease/Pneumonitis [see Warnings and Precautions (5.1)] Severe Cutaneous Adverse Reactions [see Warnings and Precautions (5.2)] QT Interval Prolongation [see Warnings and Precautions (5.3, 5.4)] Hepatotoxicity [see Warnings and Precautions (5.5)] Neutropenia [see Warnings and Precautions (5.6)] In patients with early breast cancer, the most common (incidence ≥ 20%) adverse reactions, including laboratory abnormalities, are lymphocytes decreased, leukocytes decreased, neutrophils decreased, hemoglobin decreased, alanine aminotransferase increased, aspartate aminotransferase increased, infections, creatinine increased, platelets decreased, headache, nausea, and fatigue. ( 6 ) In patients with advanced or metastatic breast cancer, the most common (incidence ≥ 20%) adverse reactions, including laboratory abnormalities, are leukocytes decreased, neutrophils decreased, hemoglobin decreased, lymphocytes decreased, aspartate aminotransferase increased, gamma glutamyl transferase increased, alanine aminotransferase increased, infections, nausea, creatinine increased, fatigue, platelets decreased, diarrhea, vomiting, headache, constipation, alopecia, cough, rash, back pain, and glucose serum decreased.
Source: FDA drug label, Novartis Pharmaceuticals Corporation, effective July 1, 2026 (SPL set aaeaef94-f3f5-4367-8ea2-b181d7be2da8), via openFDA; the full label on DailyMed
What do FAERS reports show?
31,378 reports list ribociclib among the medicines taken, each a report of something that happened, not proof the medicine caused it; 4,597 are coded as a death and 7,206 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 24 reactions below, 17 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Ribociclib: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions