The medical process of surrogacy differs from a personal pregnancy, especially when it comes to medication. During gestational surrogacy, the uterus needs to be carefully prepared so it can support an embryo and early pregnancy. To do this, the natural cycle is temporarily paused, the uterine lining is encouraged to thicken and hormone levels are kept steady. Medications like estrogen, progesterone and Lupron (leuprolide) help make these steps possible.
In this guide, we’ll go over how these medications work, why they’re used in surrogacy and what surrogates can expect throughout the process.
Why Surrogacy Requires Medication
In a natural cycle, your hormones rise and fall on their own to prepare for ovulation and possible pregnancy. In gestational surrogacy, the surrogate’s eggs aren’t being used, so the body isn’t sending those same natural signals. Because of this, the cycle needs to be temporarily paused and replaced with a carefully timed “medicated cycle.”
This helps the clinic:
- Match the surrogate’s cycle with the egg donor or intended mother
- Create a thick, healthy uterine lining for the embryo
- Prevent the body from ovulating too early
- Support early pregnancy until the placenta takes over around week 12
Some clinics may also recommend a mock cycle before the real one to see how the uterine lining responds to medication and to fine-tune the plan for the actual transfer.
Hormones Involved in Surrogacy
Estrogen
Estrogen is a hormone that plays an important role in preparing the uterus for pregnancy. During a medicated surrogacy cycle, estrogen helps thicken and strengthen the uterine lining so it’s ready for an embryo.
Even though it may seem surprising, many surrogates start birth control pills early in the process to help the clinic control the timing of the cycle. After that, estrogen is added to help the uterine lining grow. Most surrogates take estrogen until about the 12th week of pregnancy, when the placenta starts making hormones on its own.
Estrogen may be prescribed as:
- Oral pills
- Patches
- Suppositories
- Injections
Progesterone
Progesterone is another important hormone. Your body normally makes it after ovulation, and it helps the uterus prepare for a possible pregnancy.
In surrogacy, once the uterine lining is thick enough, progesterone is added to support implantation. It usually starts about five days before the embryo transfer. This hormone helps the embryo attach and grow. Like estrogen, progesterone is usually taken until around the 12th week of pregnancy.
Progesterone may be prescribed as:
- Pills
- Vaginal suppositories or gel
- Intramuscular injections (most common in IVF cycles)
Lupron (Leuprolide)
Lupron (leuprolide) is a medication that temporarily turns off the body’s natural hormonal cycle. This allows the clinic to control the timing of the process better.
Because several hormones are being introduced, the body might try to start its own cycle again. Lupron helps prevent that by stopping early ovulation and keeping the surrogate’s cycle in sync with the egg donor or intended mother.
Lupron usually starts about two weeks after beginning birth control and stops a few days before the egg retrieval. It’s given as a small self-injection with a short needle, which most surrogates adjust to quickly.
It’s normal to have questions or concerns about these medications. Your doctor will explain what to expect, how to reduce risks and cope with side effects.
Contact Joy of Life for Personal Guidance
Individual protocols vary by clinic and by surrogate. To understand your exact medication plan and receive personalized guidance, contact Joy of Life. Our team includes medical professionals and experienced surrogates who walk with you through each step of the process.
Other Medications Surrogates May Take
Surrogacy medications can include more than just hormones. Some additional medications your clinic may recommend are:
- Prenatal vitamins: These help support a healthy pregnancy and make sure you’re getting important nutrients.
- Low-dose aspirin: Some clinics use this to help improve blood flow to the uterus and lower the chance of blood clots.
- Antibiotics: Medications like doxycycline or tetracycline may be given to prevent or treat infection before the embryo transfer.
Not every surrogate will need all of these. Your care team will decide what’s right for you and will keep an eye on your progress through regular blood tests and ultrasounds to make sure everything is going well.
Timeline for Taking Surrogacy Medications
Every clinic has its own routine, but most surrogate medication schedules follow the same basic flow. Here’s a simple look at what usually happens from the first medication to embryo transfer and early pregnancy.
1. Birth Control Pills
Most cycles start with a short round of birth control pills. This helps the clinic plan the timing so everything lines up for your transfer month. It’s an easy way to begin the cycle in a predictable, controlled way.
2. Lupron (Leuprolide)
Toward the end of your birth control phase, you’ll start Lupron injections. Lupron quiets your natural cycle so the clinic can guide the timing.
3. Estrogen
Once your natural cycle is fully paused, estrogen is added to help the uterine lining grow. This is the stage at which your body begins to create the ideal environment for the embryo.
4. Monitoring Appointment
After you’ve been on estrogen for a while, you’ll come in for a lining check. Your care team assesses the thickness of the uterine lining and checks your hormone levels to ensure everything is on track. If needed, they may adjust your medication slightly.
5. Progesterone
When your lining is ready, progesterone is added. This medication helps your body reach the exact timing needed for embryo transfer. You’ll continue progesterone until the placenta takes over hormone production later in the first trimester.
6. Embryo Transfer
After five days of progesterone (for a day-5 embryo), it’s transfer day. The embryo is gently placed into the uterus in a quick, simple procedure. You’ll continue your medications as directed. Many surrogates say this is one of the most special moments of the process.
7. Post-Transfer Monitoring
Around 9-12 days after transfer, you’ll return for your first HCG blood test to check for pregnancy. A couple of days later, a second test helps confirm that levels are rising. An early ultrasound usually happens around weeks 6 or 7. Medications continue through the end of the first trimester.
Once these medications taper off, your body naturally takes over. From that point on, the pregnancy often feels much like any other healthy pregnancy — but the purpose behind it makes the journey especially meaningful.
Ready to Begin Your Surrogacy Journey?
If you’re ready to take the next step, Joy of Life is here to support you with experience, compassion and dedicated guidance.
Apply to become a surrogate today.
Frequently Asked Questions About Surrogacy Medications
What is a mock cycle?
Some fertility clinics use a mock cycle before the actual embryo transfer to see how the surrogate’s body responds to medication. A mock cycle helps the clinic fine-tune medication doses and timing so the real transfer has the best chance of success. It usually takes place one cycle before the actual transfer and follows a shortened version of the same protocol.
Do all surrogates take the same medications?
Not always. Most protocols follow the same general pattern, but the exact medications and timing can vary by clinic, embryo type and how your body responds. Your care team personalizes your plan and closely monitors your progress.
Are surrogacy injections painful?
Most surrogates describe Lupron as very manageable since it uses a small needle. Progesterone injections can be more noticeable because they go into the muscle, but massaging afterward and rotating injection sites make a big difference.
What happens if I miss a dose of hormones?
Mistakes happen, and clinics know that. You’ll receive clear instructions on what to do if a dose is late or skipped, and you can always call your nurse for guidance. Staying as close to schedule as possible is important, but you’re never expected to navigate it alone.
Are there long-term side effects from surrogacy medications?
These medications are designed for short-term use and are commonly used in IVF. Your medical team reviews your health history beforehand and monitors you throughout the process to ensure everything stays safe and appropriate for your body.
Why do I need so many medications if I’m already healthy?
Surrogacy relies on precise timing. Because the surrogate isn’t using her own eggs, the body isn’t producing the natural hormonal signals that would typically prepare the uterus for implantation. Medications temporarily step in to create the right environment until the pregnancy is established.
*The information on this page was written or reviewed for accuracy by Joy Millan, the founder and CEO of Joy of Life. Meet Joy and our team.
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