Short answer: The Cetrotide label gives 0.25 mg injected under the skin once daily, starting on stimulation day 5 (morning or evening) or day 6 (morning), and continued daily until the day hCG is given. Ovarian stimulation with FSH or hMG starts on cycle day 2 or 3. In the clinical studies, the median length of daily Cetrotide was 5 days (range 1 to 15).
This is what the FDA label says. Follow your prescriber. Your prescriber may use a different dose or pace than the label's standard schedule.
What Cetrotide is approved for: Cetrotide is a GnRH antagonist approved to prevent premature LH surges (early ovulation) in women having controlled ovarian stimulation (Indications and Usage). It is used alongside FSH or hMG during an IVF or ICSI stimulation cycle.
Source
Cetrotide (cetrorelix acetate for injection) 0.25 mg, prescribing information and Patient Leaflet. EMD Serono. DailyMed, version published September 29, 2025. DailyMed setid aca7768e-28a7-4027-b1d8-e66247665f79
Each tray holds a vial of 0.25 mg powder, a prefilled syringe of 1 mL Sterile Water for Injection, a 20 gauge (yellow) needle for mixing and a 27 gauge (grey) needle for injecting (How Supplied).
The water is injected into the vial, the vial is gently swirled until clear, the whole contents are drawn back, and the needle is changed before injecting. The solution is used immediately (Dosage and Administration and Patient Leaflet).
It is injected under the skin of the lower belly, at least one inch from the navel, using a different site each day. Women can self-inject after instruction from their doctor (Dosage and Administration).
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Step | What the label says |
|---|---|
| Ovarian stimulation (FSH or hMG) | Started on cycle Day 2 or 3; dose adjusted according to individual response |
| Cetrotide start | 0.25 mg on stimulation day 5 (morning or evening) or day 6 (morning) |
| Cetrotide dose | 0.25 mg subcutaneously once daily |
| How long | Continued daily until the day of hCG administration |
| Trigger | hCG when ultrasound shows a sufficient number of follicles of adequate size; no hCG if the ovaries show an excessive response |
In the two multiple-dose studies, the median number of days of Cetrotide treatment was 5 (range 1-15).
LH suppression begins about two hours after the 0.25 mg dose, and a dose every 24 hours has been shown to maintain the effect. The effects on LH and FSH reverse after treatment stops.
The label's studies also used a single 3 mg dose around stimulation day 7, with 0.25 mg daily added from 96 hours later if hCG had not been given within 4 days. Only the 0.25 mg kit is supplied.
Cetrotide 0.25 mg is stored refrigerated at 2 to 8 C (36 to 46 F), with the tray kept in the outer carton to protect it from light.
The syringe and needles are used only once and disposed of right after use, ideally in a medical waste container.
The Cetrotide label gives no missed-dose instruction. Ask your fertility team what to do if a dose is missed or late.
In Dose Track you set up Cetrotide as a protocol with the dose and schedule your prescriber gave you. A protocol can hold dose steps, each with its own dose and length in days or weeks, so a step-up plan like the one on the label can be entered once and the app moves to the next step on its own. Reminders follow the schedule, and every dose is logged with the date and time, so you can see which step you are on and when your last dose was. The app follows what you enter; it does not choose or change a dose.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.