Surrogacy Medications Explained: What Injections You'll Actually Take (And What They Feel Like)

Ask a room full of experienced surrogates what they were most nervous about before their first journey, and most won't say the pregnancy. They'll say the needles. So let's demystify the entire medication protocol — what you'll take, why, for how long, and honestly, what it feels like.

One important note before we start: your exact protocol comes from the intended parents' fertility clinic, not from your agency, and protocols vary. This is the typical shape of a medicated frozen embryo transfer (FET) cycle — the most common protocol in gestational surrogacy today.

Phase 1: Suppression (Weeks 1–3)

Before your body can run the clinic's schedule, it has to stop running its own. Many protocols start with either birth control pills or Lupron (leuprolide), a small daily injection that pauses your natural cycle.

• What it is: a tiny insulin-style needle, injected into the belly fat
• What it feels like: most surrogates rate it a 1 out of 10 — a quick pinch, done in seconds
• Side effects: some women get mild headaches or hot flashes as hormones dip. They pass.

Phase 2: Building the Lining (Weeks 3–5)

Next comes estrogen, which thickens your uterine lining so the embryo has somewhere plush to land. Estrogen comes in three forms, and clinics choose based on how your lining responds:

• Pills (Estrace): taken orally or vaginally, no needles involved
• Patches: small stickers on the belly, changed every couple of days
• Injections (estradiol valerate): an intramuscular shot usually given just twice a week

During this phase you'll have monitoring appointments — a quick transvaginal ultrasound and blood draw every several days, usually at a clinic near your home. The clinic is watching for a lining around 7–8mm or more with a trilaminar (three-layer) pattern. When your lining is ready, transfer gets scheduled.

Phase 3: Progesterone — The Famous PIO Shots (Week 5 Through ~Week 12 of Pregnancy)

This is the one everybody talks about. Progesterone-in-oil (PIO) is an intramuscular injection, usually given daily in the upper outer quadrant of the hip/glute, starting about five days before transfer and continuing until roughly week 10–12 of pregnancy, when the placenta takes over hormone production.

Honest answers to the questions everyone asks:

• Does it hurt? The needle is longer (1–1.5 inches) because it has to reach muscle, but the injection site is chosen precisely because it's not very nerve-dense. Most surrogates say the anticipation is worse than the shot. The soreness afterward — like a small bruise — is the more noticeable part.
• Can I do it myself? Many surrogates do, using a mirror. Others have a partner, friend, or even a trained neighbor do it. Your clinic will teach whoever is helping you.
• The tricks experienced surrogates swear by: warm the oil vial in your bra or a rice sock for 10 minutes first; ice the site for 60 seconds before injecting; massage and apply heat afterward; rotate sides every day; draw with a big needle, inject with a smaller one.

Some clinics allow vaginal progesterone suppositories instead of (or alongside) PIO — no needles at all. It's worth asking, though many clinics still consider daily PIO the gold standard for surrogacy cycles.

The Full Timeline at a Glance

• Weeks 1–3: suppression (birth control and/or Lupron)
• Weeks 3–5: estrogen + monitoring appointments
• 5 days before transfer: progesterone begins
• Transfer day: a 15–30 minute procedure, no anesthesia needed — read our day-by-day transfer guide
• Weeks 10–12 of pregnancy: weaning off all medications — after that, it's a regular pregnancy

Who Pays for All of This?

Not you. Ever. Every medication, monitoring appointment, and clinic visit is paid by the intended parents. At OFG, you'll also receive a monthly allowance once medications begin, and mileage reimbursement for every monitoring appointment. See our full compensation breakdown for how that works.

The Question Behind the Question

When women ask about medications, they're often really asking: "Will I still feel like myself?" The honest answer: mostly yes, with moody or bloated days sprinkled in — similar to a strong PMS month. The medication phase is temporary, it's closely monitored, and you will have a coordinator who has walked dozens of women through it and answers texts at 9pm when the vial looks cloudy and you're not sure if that's normal. (It usually is.)