Fertility Medications by Diagnosis: A Scenario-by-Scenario Guide
A scenario guide to fertility medications by treatment type — IUI, IVF, PCOS, and embryo transfer. For anyone trying to understand their medication plan.
The same drug names show up across different fertility treatments, but they're not used the same way. The medications prescribed for ovulation induction look different from an IVF stimulation protocol, and a PCOS-specific plan is different still. This page maps the most common scenarios to the medications typically involved, so you can understand why you're taking what you're taking.
What fertility medication is typically used for PCOS?
PCOS protocols are built around lowering stimulation risk while still achieving ovulation. Letrozole is the preferred oral agent — it's used at a lower dose than in other ovulation induction protocols to reduce the risk of multiple pregnancy, since PCOS ovaries tend to respond more strongly to stimulation. Metformin is often added to improve insulin sensitivity and may also reduce the risk of ovarian hyperstimulation syndrome (OHSS). Because PCOS ovaries can over-respond even on conservative dosing, extra monitoring for OHSS is standard in PCOS-specific protocols.
What medications are used for an IUI cycle?
IUI cycles typically use letrozole or Clomid to provide mild stimulation and help time ovulation — occasionally gonadotropins are used for a stronger response. The trigger shot (an hCG-based medication such as Ovidrel or Novarel) is then given to precisely time ovulation, and the IUI procedure is performed 24 to 36 hours later. The goal in an IUI cycle is controlled, monitored stimulation — enough to improve timing and odds, without over-responding.
What medications are used during a full IVF cycle?
Standard IVF stimulation involves daily FSH injections — typically Gonal-F, Follistim, or Menopur — for 8 to 12 days. These are paired with an LH suppressor to prevent premature ovulation: in the most common approach (the antagonist protocol), this is Ganirelix or Cetrotide; in the long agonist protocol, it's Lupron started earlier in the cycle. As stimulation progresses, a trigger shot finalizes egg maturation before retrieval — the choice between an hCG trigger, a Lupron trigger, or a dual trigger depends on individual OHSS risk and prior cycle response. Protocol selection for a given patient depends on AMH, age, and any prior stimulation history.
What is a frozen embryo transfer protocol?
The core medication in a frozen embryo transfer (FET) is progesterone, which sustains the uterine lining after ovulation or transfer and supports an early pregnancy if implantation occurs. Progesterone for FET is given as intramuscular injections (PIO — effective but uncomfortable for many), vaginal suppositories or gels (Crinone, Endometrin), or oral capsules, which are considered less reliable. If the pregnancy is confirmed, progesterone support typically continues to approximately 10 to 12 weeks. Your clinic will outline the full FET preparation protocol, which includes how the lining is prepared before progesterone begins.
What medications are used for ovulation induction?
Ovulation induction starts with oral agents. Letrozole is the preferred first-line option for most patients — it produces better live-birth rates and fewer side effects than Clomid for the majority of ovulation induction indications. Clomid (clomiphene) is the older alternative; it still works and is still used, with common side effects including hot flashes and mood shifts. Either is given as a 5-day course early in the cycle and monitored by ultrasound to confirm follicle development. If oral agents fail to produce ovulation or a pregnancy over a few cycles, gonadotropin injections are the escalation — more potent, with higher multiple-pregnancy risk, and requiring close monitoring throughout.
Why do fertility doctors use letrozole instead of Clomid?
Letrozole has overtaken Clomid as the standard for most ovulation induction indications because the evidence supports better live-birth rates and fewer side effects. For PCOS specifically, letrozole is the preferred choice — it produces better outcomes for ovulation induction in this population compared to Clomid. Clomid is older and still used in some protocols and clinical contexts, but letrozole is now considered first-line for most patients being treated for ovulation problems.
What medications support implantation after an embryo transfer?
Progesterone is the primary medication used to support implantation and early pregnancy after an embryo transfer. It sustains the uterine lining during the critical window following transfer. The three delivery forms are intramuscular injection (PIO — effective but physically uncomfortable), vaginal suppositories or gels such as Crinone or Endometrin, and oral capsules, which are considered less reliable than the other forms. If pregnancy is confirmed, progesterone support continues until approximately 10 to 12 weeks of gestation.