Urofollitropin (Purified FSH)
Urofollitropin is highly purified FSH extracted from the urine of postmenopausal women, with LH activity largely removed. It is used for ovulation induction and controlled ovarian stimulation, particularly where a pure FSH effect is wanted, such as PCOS-related ovulation induction.
01 Overview
Urofollitropin is a urinary-derived gonadotropin refined to remove most LH and contaminating proteins, leaving predominantly FSH bioactivity. It predates recombinant FSH and remains in use.
It stimulates follicular growth for IVF and for ovulation induction, and its LH-poor profile is sometimes preferred in women (such as some with PCOS) who already have adequate or high endogenous LH.
02 Mechanism
Provides purified exogenous FSH that binds ovarian granulosa-cell FSH receptors to drive follicular maturation.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Ovulation induction | 75–150 IU/day | SubQ | Start 75-150 IU daily, titrate by follicular response |
| IVF stimulation | 150–225 IU/day | IM | 150-225 IU daily individualised |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Follicular developmentInduces mono- or multi-follicular growth for ovulation induction or IVF. | Clinical | ||
| LH-poor stimulationMinimal LH content can suit women with adequate endogenous LH. | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Ovarian hyperstimulation syndrome (OHSS)Ovarian enlargement and fluid shifts from over-response, notably in PCOS. | Severe | Uncommon | Clinical | |
| Multiple pregnancySeveral mature follicles raise multiple-pregnancy risk. | Moderate | Common with ovulation induction | Clinical |