What the label lists and what reports show
Vincristine side effects
Vincristine's FDA label: “The most common adverse reaction is hair loss; the most troublesome adverse reactions are neuromuscular in origin.” FAERS holds 29,131 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 febrile neutropenia (4,418 reports).
- Generic listed
- Boxed warning
Check it at the source: the vincristine FDA label on DailyMed (effective February 17, 2026, Hospira, Inc.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsThe most common adverse reaction is hair loss; the most troublesome adverse reactions are neuromuscular in origin.
From the label: adverse reactions, continuedPrior to the use of this drug, patients and/or their parents/guardian should be advised of the possibility of untoward symptoms. In general, adverse reactions are reversible and are related to dosage. The most common adverse reaction is hair loss; the most troublesome adverse reactions are neuromuscular in origin. When single, weekly doses of the drug are employed, the adverse reactions of leukopenia, neuritic pain, and constipation occur but are usually of short duration (ie., less than 7 days). When the dosage is reduced, these reactions may lessen or disappear. The severity of such reactions seems to increase when the calculated amount of drug is given in divided doses. Other adverse reactions, such as hair loss, sensory loss, paresthesia, difficulty in walking, slapping gait, loss of deep–tendon reflexes, and muscle wasting, may persist for at least as long as therapy is continued. Generalized sensorimotor dysfunction may become progressively more severe with continued treatment. Although most such symptoms usually disappear by about the sixth week after discontinuance of treatment, some neuromuscular difficulties may persist for prolonged periods in some patients. Regrowth of hair may occur while maintenance therapy continues. …
Source: FDA drug label, Hospira, Inc., effective February 17, 2026 (SPL set b22e4c8e-dbe1-4d4b-a026-e1812974071c), via openFDA; the full label on DailyMed
What do FAERS reports show?
29,131 reports list vincristine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 5,379 are coded as a death and 14,062 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, 8 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?
- Vincristine: 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