Menopur is an injectable fertility medication that stimulates your ovaries to grow multiple egg-containing follicles at once. It contains two key reproductive hormones, FSH and LH, in equal amounts (75 International Units of each per vial). It’s primarily used during IVF cycles to help produce enough mature eggs for retrieval.
How Menopur Works in Your Body
Your ovaries naturally develop one dominant follicle each month in response to hormones from your pituitary gland. Menopur overrides that process by flooding your system with higher levels of both follicle-stimulating hormone (FSH) and luteinizing hormone (LH). FSH drives the growth of multiple follicles simultaneously, while LH supports estrogen production inside those follicles. The combination mimics what your body produces naturally, just in much larger quantities.
As follicles grow, they produce rising levels of estradiol (a form of estrogen). There’s a strong correlation between total follicular volume and estradiol levels, which is why your clinic tracks both throughout your cycle. The goal is to push several follicles to maturity at the same time rather than letting your body select just one winner.
When Menopur Is Used
The FDA-approved indication for Menopur is the development of multiple follicles in women participating in assisted reproductive technology (ART) programs, most commonly IVF. Your doctor may also use it alongside other medications in IUI (intrauterine insemination) cycles, though the primary use is egg retrieval for IVF or egg freezing.
In a typical IVF protocol, you’ll first take a medication to suppress your pituitary gland so your body doesn’t trigger ovulation on its own. Once suppression is confirmed, Menopur injections begin, usually on day 2 or 3 of your cycle. A final “trigger shot” of hCG is given once your follicles reach the right size, prompting the eggs inside to complete their final stage of maturation before retrieval.
What the Injection Process Looks Like
Menopur comes as a powder that you mix with a small vial of sterile liquid before each injection. Using a syringe with a mixing adapter (called a Q-cap), you draw up 1 mL of the liquid, inject it into the powder vial, and swirl gently until dissolved. If your dose requires more than one vial of powder, you draw the mixed solution back up and use that same liquid to dissolve the next vial. Regardless of how many powder vials your dose requires, you always inject just 1 mL of fluid.
The injection is subcutaneous, meaning it goes into the fatty tissue just below the skin, typically in the lower abdomen. You’ll rotate injection sites from day to day to avoid soreness. Before mixing, the powder can be stored in the refrigerator or at room temperature (between 37°F and 77°F).
Dosing and How It’s Adjusted
The standard starting dose is 225 International Units per day. After the first five days, your doctor adjusts the dose based on how your follicles are responding. These adjustments happen no more often than every two days, in increments of up to 150 IU at a time. The maximum daily dose is 450 IU, and treatment generally doesn’t extend beyond 20 days.
Dose adjustments are guided by two things: ultrasound measurements of your follicles and blood tests measuring your estradiol levels. Ultrasound provides more precise information about the number and size of individual follicles than blood work alone, since multiple small follicles can produce the same estradiol level as a single large one. That’s why your clinic will schedule frequent monitoring appointments, often every one to two days during the later part of stimulation.
Side Effects and Ovarian Hyperstimulation
The most common side effects are the ones you’d expect from stimulating your ovaries: bloating, abdominal discomfort, and tenderness at the injection site. Some women also experience headaches, nausea, or mood changes from the hormonal shifts.
The more serious risk is ovarian hyperstimulation syndrome (OHSS), where the ovaries overrespond and swell significantly, sometimes causing fluid to leak into the abdomen. In clinical studies of gonadotropin medications, OHSS occurred in roughly 5% of treatment cycles, with severe cases in about 0.2%. Your clinic’s monitoring protocol exists largely to catch signs of overstimulation early. If your ovaries appear abnormally enlarged near the end of stimulation, your doctor will withhold the trigger shot to prevent OHSS from worsening. There’s also a small increased risk of blood clots, particularly if OHSS develops alongside pregnancy.
Menopur vs. Recombinant FSH Products
Menopur is derived from purified human urine (specifically from postmenopausal women, whose urine is rich in FSH and LH). The main alternative is lab-manufactured recombinant FSH, which contains FSH only and no LH activity. You might wonder whether one produces better results than the other.
A meta-analysis comparing Menopur to recombinant FSH found no meaningful difference in ongoing pregnancy rates or live birth rates. The combined data showed a live birth rate ratio of 1.14 per embryo transfer, which was not statistically significant. In practical terms, neither medication has proven clinical superiority over the other. Your doctor’s choice between them often comes down to your specific hormonal profile, how much LH activity your protocol needs, and sometimes cost or insurance coverage.
What to Expect During a Menopur Cycle
Most women inject Menopur for 8 to 12 days, though some cycles run shorter or longer depending on response. During that time, you’ll visit your clinic frequently for blood draws and ultrasounds. Early in stimulation, appointments may be every two to three days. As follicles approach maturity, monitoring often becomes daily.
Physically, you’ll likely notice increasing abdominal fullness and pressure as your ovaries enlarge. By the end of stimulation, your ovaries may be several times their normal size, each containing multiple fluid-filled follicles. This is expected and temporary, but it can be uncomfortable. Most women find that the discomfort peaks around egg retrieval and resolves within a week or two afterward, or within one to two menstrual cycles if OHSS symptoms develop.