Short answer: The Zoladex 3.6 mg label says that while a delay of a few days is permissible, every effort should be made to adhere to the 28-day schedule. It also says women who miss one or more doses in a row may have breakthrough menstrual bleeding. The implant is given under a physician's supervision, so timing is set with the clinic.
| Situation | What the label says |
|---|---|
| Schedule | One 3.6 mg implant under the skin of the belly every 28 days (2.1, 2.7) |
| Delay of a few days | Permissible (2) |
| Keeping the schedule | Every effort should be made to adhere to the 28-day schedule (2) |
| Missed one or more doses (women) | May have breakthrough menstrual bleeding (17.3) |
Section 2 (Dosage and Administration) says: while a delay of a few days is permissible, every effort should be made to adhere to the 28-day schedule. Zoladex 3.6 mg is given as one implant under the skin of the belly every 28 days.
The label does not define "a few days", and it does not say how to reset the schedule after a late implant. Those are questions for the clinic that gives the implant.
Section 17.3 says menstruation should stop with effective doses, and that patients missing one or more successive doses of Zoladex may experience breakthrough menstrual bleeding. It also says to tell the physician if regular menstruation persists.
This page summarizes FDA labeling. It is not personalized medical advice; confirm what to do with your prescriber or pharmacist.