Inclusion Criteria:  Adult patient, male or female, either  treated with chemotherapy for hematological cancer (leukemia, lymphoma) and suffering from grade 2 to 4 mucositis (according to WHO / NCI-CTCAE), or treated with radiotherapy or radio-chemotherapy (cisplatin or cetuximab) for head and neck cancer and suffering from grade 2 to 4 mucositis (according to WHO / NCI-CTCAE), Agreeing not to take any treatment for mucositis other than the treatment proposed in this study, apart from the classic symptomatic treatment for mucositis recommended by WHO. Able to give informed consent to participate in research. Beneficiary of a Social Security scheme.  Exclusion Criteria:  A woman who is pregnant, breastfeeding, or may be. Major subject under guardianship, curators, deprived of liberty, or under the safeguard of justice. Medical and / or surgical history deemed by the investigator to be incompatible with the study because it would invalidate any reliable assessment. General state of health considered pejorative (Karnofsky index <60). Subject who received systemic antibiotic therapy in the last two weeks prior to inclusion. Type 1 or type 2 diabetic subject (presence of honey in Orosol®). Subject on an anticoagulant (AVK or AOD) (interaction of the cranberry contained in Orosol® with anticoagulants (in particular warfarin) with instability of the International Normalized Ratio; the AODs can potentially present the same type of interaction). History of administration of the treatment (or equivalent) in the study. Anticipated difficulties in reading / understanding the protocol and its questionnaires. Subjects in the exclusion period from another clinical trial Refusal of participation.