The most common side effects with Javlor (seen in more than 1 patient in 10) are neutropenia, leucopenia (low white-blood-cell counts), anaemia (low red-blood-cell counts), thrombocytopenia (low platelet counts), loss of appetite, constipation, abdominal (stomach) pain, vomiting, nausea (feeling sick), stomatitis (inflammation of the lining of the mouth), diarrhoea, alopecia (hair loss), myalgia (muscle pain), asthenia (weakness) or fatigue (tiredness), injection-site reactions, fever and weight loss. For the full list of all side effects reported with Javlor, see the package leaflet.

Javlor must not be used in people who are hypersensitive (allergic) to vinflunine or other vinca alkaloids. It must not be used in patients who have or have had a severe infection within the past two weeks or in patients with a neutrophil count of less than 1,500 per mm³ for the first administration or less than 1,000 per mm³ for subsequent administrations, or a platelet count less than 100,000 per mm³. It must also not be used in breastfeeding mothers.