Gonal F Side Effects: What's Normal and What's Not

Starting Gonal F (follitropin alfa) can feel daunting, especially when you read the list of potential side effects. The reality is that most people tolerate Gonal F well, and the common side effects are manageable. But because Gonal F is a powerful fertility medication that stimulates your ovaries, there are some serious risks you need to know about — including Ovarian Hyperstimulation Syndrome (OHSS).

Here's what to expect, what's considered normal, and exactly when to call your doctor.

What Is Gonal F?

Gonal F is a recombinant follicle-stimulating hormone (FSH) made by EMD Serono. It's injected under the skin to stimulate the ovaries to develop follicles (egg-containing sacs) for fertility treatments like IVF or ovulation induction. In men, it can stimulate sperm production for certain hormonal conditions. For a deeper dive, see our complete guide to Gonal F.

Common Side Effects

These side effects are reported frequently in clinical trials and are generally mild to moderate. They don't usually require medical intervention:

• Injection site reactions — redness, bruising, swelling, or mild pain where you inject. This is the most common side effect and typically improves with practice and site rotation.
• Headache — reported in up to 22% of patients in clinical trials.
• Abdominal pain and bloating — your ovaries are growing multiple follicles, so some pelvic fullness and discomfort is expected.
• Nausea — usually mild and may come and go during stimulation.
• Breast tenderness — related to rising estrogen levels during stimulation.
• Ovarian cysts — small cysts can form during or after stimulation. Most resolve on their own without treatment.
• Pelvic discomfort — a feeling of pressure or heaviness in the lower abdomen.
• Upper respiratory infection — reported in clinical trials, though the relationship to Gonal F is unclear.
• Mood changes — irritability, emotional sensitivity, or mood swings related to hormonal shifts.

Serious Side Effects

These are less common but require immediate medical attention. Contact your doctor or go to the emergency room if you experience any of the following:

Ovarian Hyperstimulation Syndrome (OHSS)

OHSS is the most significant risk of Gonal F treatment. It happens when the ovaries over-respond to stimulation, becoming swollen and leaking fluid into the abdomen. Symptoms range from mild to life-threatening:

• Mild OHSS: Bloating, mild abdominal pain, nausea, diarrhea. Affects up to 20-30% of stimulation cycles to some degree.
• Moderate OHSS: Significant abdominal distension, vomiting, rapid weight gain (more than 2 pounds per day), decreased urination.
• Severe OHSS: Severe abdominal pain, rapid weight gain, difficulty breathing, blood clots, kidney problems, and fluid accumulation in the abdomen or chest. This is a medical emergency.

Your fertility clinic monitors for OHSS with ultrasounds and blood tests throughout your cycle. If you're at high risk, your doctor may adjust your dose, use a different trigger shot, or freeze all embryos instead of doing a fresh transfer.

Thromboembolic Events (Blood Clots)

Gonal F treatment, especially when OHSS develops, can increase the risk of blood clots in the legs (deep vein thrombosis) or lungs (pulmonary embolism). Seek immediate care if you experience sudden leg swelling, pain, chest pain, or shortness of breath.

Ovarian Torsion

Enlarged ovaries can twist on their blood supply, causing sudden, severe pelvic pain. This is a surgical emergency. If you develop sudden, sharp, one-sided pelvic pain during or after stimulation, go to the ER immediately.

Multiple Pregnancies

Gonal F can cause multiple eggs to mature, increasing the risk of twins, triplets, or higher-order multiples. Your doctor monitors follicle development to manage this risk, and may cancel a cycle if too many follicles develop.

Allergic Reactions

Rare but possible. Signs include hives, swelling of the face or throat, difficulty breathing, or a rapid heartbeat. Seek emergency care immediately.

Pulmonary Complications

In rare cases, severe OHSS can lead to fluid around the lungs, difficulty breathing, or acute respiratory distress syndrome (ARDS).

Side Effects in Specific Populations

Men Using Gonal F

Men prescribed Gonal F for hypogonadotropic hypogonadism may experience injection site reactions, headache, and acne. OHSS does not apply to male patients.

Pregnancy

Gonal F is contraindicated in pregnancy (Category X). It should only be used before conception as part of a fertility protocol. Once pregnancy is confirmed, Gonal F is discontinued.

Older Reproductive-Age Women

Women over 35 may have a reduced ovarian response to Gonal F, potentially requiring higher doses. Higher doses can increase side effect risk, so monitoring is especially important.

How to Manage Common Side Effects

• Injection site reactions: Rotate injection sites between the left and right sides of your lower abdomen. Let the alcohol swab dry before injecting. Ice the area for a few minutes before and after if needed.
• Bloating and abdominal discomfort: Avoid strenuous exercise, drink plenty of fluids, and eat small, frequent meals. Salty foods and electrolyte drinks can help if your doctor recommends them.
• Headache: Acetaminophen (Tylenol) is generally safe during fertility treatment. Avoid ibuprofen (Advil) and other NSAIDs unless your doctor approves — they may interfere with ovulation and implantation.
• Mood changes: Hormonal fluctuations are real. Let your partner and support system know what you're going through. Talk to your care team if mood changes become severe.
• Nausea: Eat small meals, stay hydrated, and avoid spicy or greasy foods. Ginger tea or candies may help.

When to Call Your Doctor

Call your fertility clinic or doctor right away if you experience:

• Rapid weight gain (more than 2 pounds per day)
• Severe bloating or abdominal pain
• Difficulty breathing or chest pain
• Decreased urination
• Sudden sharp pelvic pain on one side
• Leg swelling or pain
• Signs of an allergic reaction
• Fever over 101°F

Most fertility clinics have an after-hours nurse line for urgent questions. Don't hesitate to use it.

Final Thoughts

Most Gonal F side effects are mild and temporary — injection site soreness, bloating, and headaches are the most common. The serious risks, particularly OHSS, are real but manageable with proper monitoring. Your fertility team tracks your response with regular ultrasounds and blood work specifically to catch problems early.

Understanding what's normal and what's not helps you feel more confident during treatment. If something doesn't feel right, trust your instincts and call your clinic.

For more about Gonal F, check out how Gonal F works or learn about Gonal F drug interactions. If you're having trouble finding Gonal F at your pharmacy, Medfinder can help you check stock in real time.