Short answer: Follitropin has a half-life of about 33 hours (Follistim AQ) to 53 hours (Gonal-f RFF). Levels peak about 13 hours (Follistim AQ) to 15.5 hours (Gonal-f RFF) after a dose. People vary, so treat these as estimates.
Follitropin is a lab-made version of FSH (follicle-stimulating hormone), the pituitary hormone that drives egg follicles in women and sperm production in men. Follitropin alfa is sold as Gonal-f (EMD Serono) and follitropin beta as Follistim AQ (Organon), both injected under the skin in fertility treatment.
Also known as: Gonal-f, Gonal-f RFF Redi-ject, Follistim AQ, follitropin alfa, follitropin beta, FSH.
Gonal-f RFF Redi-ject is a ready-to-use multiple-dose pen in 300, 450 and 900 IU sizes, dialed in 12.5 IU steps. Follistim AQ Cartridge is a ready-to-use solution in 300, 600 and 900 IU cartridges used only with the Follistim Pen. Neither is mixed. The Follistim label says its pen delivers on average 18% more follitropin beta than the old syringe form, so switching brands, types or devices may need a dose change.
If you also use a powder peptide, the free peptide reconstitution calculator handles the vial math.
Both labels approve follitropin to induce ovulation in women whose infertility is functional and not from primary ovarian failure, and to grow multiple follicles in assisted reproduction (IVF or ICSI). The Follistim AQ label also approves it to start sperm production in men with hypogonadotropic hypogonadism. Label starting doses: Gonal-f RFF Redi-ject, 75 IU a day for ovulation induction (up to 300 IU) and 150 IU a day for ART (225 IU at 35 or older, up to 450 IU); Follistim AQ, 50 IU a day for ovulation induction (up to 250 IU), 200 IU a day for IVF or ICSI (up to 500 IU), and 450 IU a week with hCG for men. Doses are adjusted by ultrasound and estradiol under a fertility specialist.
Neither label has a boxed warning. Warnings cover ovarian hyperstimulation syndrome (OHSS), abnormal ovarian enlargement, lung and blood vessel complications including clots, ovarian torsion, multiple births, ectopic pregnancy and miscarriage, and allergic reactions. A missed dose is not doubled; the labels say to call the provider. Full numbers are on the Gonal-f side effects, Gonal-f dosing schedule, missed Gonal-f dose, Follistim AQ side effects, Follistim AQ dosing schedule and missed Follistim dose pages. Storage: Gonal-f and Follistim AQ. Comparisons: Follistim vs Gonal-f, Menopur vs Gonal-f and Follistim vs Menopur.
The Follistim AQ Cartridge label gives, after a single 150 IU injection under the skin in women, a mean time to peak of 12.9 hours and an elimination half-life of 33.4 hours. The Gonal-f RFF Redi-ject label gives, after a single 300 IU dose in healthy volunteers, a time to peak of 15.5 hours and a half-life of 53 hours, and says absorption is slower than elimination, so absorption sets the pace.
Numbers shown are taken from the source above. Half-life varies from person to person and with injection site.
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