What the label lists and what reports show
Venetoclax side effects
Venetoclax's FDA label: “In CLL/SLL, the most common adverse reactions (≥20%) for VENCLEXTA when given in combination with obinutuzumab or rituximab or as monotherapy are neutropenia, thrombocytopenia, anemia, diarrhea, nausea, upper respiratory tract infection, cough …” FAERS holds 61,220 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 (3,427 reports).
- No generic listed
Check it at the source: the venetoclax FDA label on DailyMed (effective May 20, 2026, AbbVie Inc.); 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 VENCLEXTA?VENCLEXTA can cause serious side effects, including: See "What is the most important information I should know about VENCLEXTA?" Low white blood cell count (neutropenia). Your healthcare provider will do blood tests to check your blood count during treatment with VENCLEXTA and may pause dosing of VENCLEXTA or give you medicines to help treat your neutropenia if it is severe. Infections. Death and serious infections such as pneumonia and blood infection (sepsis) have happened during treatment with VENCLEXTA. Your healthcare provider will closely monitor and treat you right away if you get a fever or any signs of infection during treatment with VENCLEXTA. Tell your healthcare provider right away if you get a fever or any signs of an infection during treatment with VENCLEXTA. […]
Source: FDA drug label, AbbVie Inc., effective May 20, 2026 (SPL set b118a40d-6b56-cee3-10f6-ded821a97018), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsIn CLL/SLL, the most common adverse reactions (≥20%) for VENCLEXTA when given in combination with obinutuzumab or rituximab or as monotherapy are neutropenia, thrombocytopenia, anemia, diarrhea, nausea, upper respiratory tract infection, cough, musculoskeletal pain, fatigue, and edema.
Table 16. Adverse Reactions Reported in ≥10% (All Grades) or ≥5% (Grade ≥3) of Patients with Previously Treated CLL/SLL Who Received VENCLEXTA Monotherapy
| Reaction | Adverse Reaction All Grades (%) | VENCLEXTA (N = 352) Grade ≥3 (%) |
|---|---|---|
| Neutropenia a | 50 | 45 |
| Anemia a | 33 | 18 |
| Thrombocytopenia a | 29 | 20 |
| Lymphopenia a | 11 | 7 |
| Febrile neutropenia | 6 | 6 |
| Diarrhea | 43 | 3 |
| Nausea | 42 | 1 |
| Abdominal pain a | 18 | 3 |
| Vomiting | 16 | 1 |
| Constipation | 16 | <1 |
| Mucositis a | 13 | <1 |
| Upper respiratory tract infection a | 36 | 1 |
| Pneumonia a | 14 | 8 |
| Lower respiratory tract infection a | 11 | 2 |
| Fatigue a | 32 | 4 |
| Edema a | 22 | 2 |
| Pyrexia | 18 | <1 |
| Musculoskeletal pain a | 29 | 2 |
| Arthralgia | 12 | <1 |
| Cough a | 22 | 0 |
| Dyspnea a | 13 | 1 |
| Headache | 18 | <1 |
| Dizziness a | 14 | 0 |
| Rash a | 18 | <1 |
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 clinically significant adverse reactions are described elsewhere in the labeling: Tumor Lysis Syndrome [see Warnings and Precautions ( 5.1 )] Neutropenia [see Warnings and Precautions ( 5.2 )] Infections [see Warnings and Precautions ( 5.3 )] In CLL/SLL, the most common adverse reactions (≥20%) for VENCLEXTA when given in combination with obinutuzumab or rituximab or as monotherapy are neutropenia, thrombocytopenia, anemia, diarrhea, nausea, upper respiratory tract infection, cough, musculoskeletal pain, fatigue, and edema. ( 6.1 ) In CLL/SLL, the most common adverse reactions (≥20%) for VENCLEXTA when given in combination with acalabrutinib are neutropenia, headache, diarrhea, musculoskeletal pain, and COVID-19. ( 6.1 ) In AML, the most common adverse reactions (≥30%) in combination with azacitidine or decitabine or low-dose cytarabine are nausea, diarrhea, thrombocytopenia, constipation, neutropenia, febrile neutropenia, fatigue, vomiting, edema, pyrexia, pneumonia, dyspnea, hemorrhage, anemia, rash, abdominal pain, sepsis, musculoskeletal pain, dizziness, cough, oropharyngeal pain, and hypotension. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact AbbVie Inc. at 1-800-633-9110 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. …
Source: FDA drug label, AbbVie Inc., effective May 20, 2026 (SPL set b118a40d-6b56-cee3-10f6-ded821a97018), via openFDA; the full label on DailyMed
What do FAERS reports show?
61,220 reports list venetoclax among the medicines taken, each a report of something that happened, not proof the medicine caused it; 17,332 are coded as a death and 23,668 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 20 reactions below, 13 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?
- Venetoclax: 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