I've had heavy menstrual bleeding out of my normal cycle; Since receiving the shot I've had 3 full very heavy menstrual cycles (1 cycle every other week); the bleeding is longer and heavier than my normal cycles; Off label use; Product use for unapproved combination; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 38 year-old female patient (not pregnant) received bnt162b2 (BNT162B2), administered in arm right, administration date 08Oct2021 12:00 (Lot number: 30145BA) at the age of 38 years as dose 3 (booster), single for covid-19 immunisation; influenza vaccine (FLU), administration date 08Oct2021 (Batch/Lot number: unknown) as dose number unknown, single for immunisation. Relevant medical history included: "Hashimotos Thyroiditis" (unspecified if ongoing). The patient's concomitant medications were not reported. Vaccination history included: Bnt162b2 (Dose 1, Lot number: EN6206, Location of injection: Arm right, Vaccine administration time: 12:00 pm), administration date: 08Mar2021, when the patient was 37 years old, for COVID-19 immunization; Bnt162b2 (Dose 2, Lot number: ER8730, Location of injection: Arm right, Vaccine administration time: 12:00 pm), administration date: 29Mar2021, when the patient was 37 years old, for COVID-19 immunization. The following information was reported: OFF LABEL USE (non-serious) with onset 08Oct2021, outcome "unknown", described as "Off label use"; PRODUCT USE ISSUE (non-serious) with onset 08Oct2021, outcome "unknown", described as "Product use for unapproved combination"; HEAVY MENSTRUAL BLEEDING (non-serious) with onset 10Oct2021 08:00, outcome "recovering", described as "I've had heavy menstrual bleeding out of my normal cycle"; MENSTRUAL DISORDER (non-serious) with onset 10Oct2021 08:00, outcome "recovering", described as "Since receiving the shot I've had 3 full very heavy menstrual cycles (1 cycle every other week)"; HEAVY MENSTRUAL BLEEDING (non-serious) with onset 10Oct2021 08:00, outcome "recovering", described as "the bleeding is longer and heavier than my normal cycles". The events "i've had heavy menstrual bleeding out of my normal cycle", "since receiving the shot i've had 3 full very heavy menstrual cycles (1 cycle every other week)" and "the bleeding is longer and heavier than my normal cycles" were evaluated at the physician office visit. Therapeutic measures were not taken as a result of heavy menstrual bleeding, menstrual disorder, heavy menstrual bleeding.  Additional information: The patient was not pregnant at the time of vaccination. The patient did not have any known allergies. The facility where the most recent COVID-19 vaccine was administered was Pharmacy or Drug Store. Prior to vaccination, the patient was not diagnosed with COVID-19. Since the vaccination, the patient had not been tested for COVID-19. The patient had heavy menstrual bleeding out of her normal cycle. Since receiving the shot she had 3 full very heavy menstrual cycles (1 cycle every other week) and the bleeding was longer and heavier than her normal cycles. This was not normal for her, her cycles were typically regular and were normal 25 day cycles. This began right after getting the 3rd COVID vaccine and her body had not returned to normal. She was currently bleeding and had been bleeding heavily for 4 days straight. The device date was reported as 01Nov2021. The case was assessed as non-serious.  No follow-up attempts are possible. No further information is expected.