IVF Medications: What They Do & Side Effects

If you’re about to begin IVF, you’ve probably seen the list of medications — and felt completely overwhelmed. Injections? Hormones? Daily pills and nasal sprays?

This post is here to demystify it all.

We’ll walk you through each type of IVF medication, what it does, how it’s usually taken, and the side effects you mightexperience. This is a UK-focused guide written for real people — with both clarity and compassion.

📖 Read next: IVF Timeline: From Start to Finish

Why So Many Medications?

IVF treatment essentially takes over your natural reproductive system in a highly controlled way. That means replacing or boosting your body’s own hormone signals at just the right time — which requires multiple medications across several stages.

You won’t necessarily take all of the ones listed here. Your fertility clinic will personalise your protocol depending on your test results, age, egg reserve, medical history, and previous response to treatment.

1. Downregulation (Turning Off Your Cycle)

Used in some protocols (like the long protocol), downregulation stops your natural hormonal cycle so the clinic can control it from scratch.

Common Medications:

• Nafarelin (Synarel) – nasal spray

• Buserelin – injection or spray

• Prostap / Zoladex – monthly depot injection

• Norethisterone - tablets

What They Do:

• Suppress ovulation

• Prevent premature hormone surges

• Temporarily mimic menopause

Side Effects:

• Hot flushes

• Headaches

• Mood swings

• Vaginal dryness

• Sleep disturbances

📌 Not all IVF patients go through this step — it depends on your protocol.

2. Ovarian Stimulation (Making Multiple Eggs)

This is the heart of IVF: daily hormone injections to stimulate your ovaries to mature multiple eggs rather than just one.

Common Medications:

• Gonal-F / Menopur / Bemfola / Fostimon / Pergoveris
  (All contain FSH, sometimes with LH)

What They Do:

• Stimulate the growth of multiple follicles (each containing an egg)

• Mimic your body’s natural follicle-stimulating hormone (FSH)

How Taken:

• Subcutaneous injections (usually into the stomach)

• Once daily, typically for 8–14 days

Side Effects:

• Bloating

• Sore ovaries

• Mood swings

• Tiredness

• Bruising at injection site

• Risk of OHSS (Ovarian Hyperstimulation Syndrome)

3. Ovulation Blockers (Preventing Early Release)

Once your follicles start maturing, you’ll also need to prevent premature ovulation.

Common Medications:

• Cetrotide

• Orgalutran

What They Do:

• Suppress LH surges to prevent eggs from being released before collection

Side Effects:

• Mild skin reactions at the injection site

• Headache

• Rare allergic reactions

4. Trigger Shot (Final Egg Maturation)

This shot times ovulation precisely before egg collection.

Common Medications:

• Ovitrelle (hCG)

• Gonasi / Pregnyl (hCG)

• Lupron / Buserelin (sometimes used instead for low OHSS risk)

What They Do:

• Final maturation of eggs

• Triggers ovulation exactly 36 hours before egg retrieval

Side Effects:

• Abdominal tenderness

• Bloating

• Moodiness

• Rare: mild OHSS if hCG is used and too many follicles respond

5. Progesterone (Luteal Phase Support)

After egg retrieval, your body may not produce enough progesterone on its own — so this is supplemented to support implantation.

Common Medications:

• Cyclogest (pessaries)

• Lubion (injection)

• Crinone (gel)

What They Do:

• Support the uterine lining

• Help create a stable environment for the embryo to implant

Side Effects:

• Bloating

• Breast tenderness

• Mood swings

• Discharge (from pessaries)

• Constipation

6. Other Medications You Might Be Given

Depending on your medical history, clinic preferences, and test results, you might also be prescribed:

• Aspirin or Clexane – to support implantation

• Prednisolone – steroid to reduce immune response

• Thyroxine – for thyroid support

• Metformin – for insulin regulation in PCOS

• Oestrogen tablets or patches – to build uterine lining

• Antibiotics – to prevent infection after procedures

These are usually tailored to your specific needs and explained clearly by your clinic.

Do the Injections Hurt?

Not as much as you think. Most IVF injections are tiny subcutaneous needles, designed to go just under the skin — not into the muscle. Many people say the anxiety is worse than the actual jab.

Tips to reduce discomfort:

• Rotate injection sites

• Let the alcohol wipe dry before injecting

• Warm the vial (briefly) in your hand

• Use ice after if needed

Emotional and Physical Side Effects

IVF medications don’t just affect your body — they can have a big emotional impact too. This is something we’re not always warned about, but it’s very real.

You might feel:

• Moodier or more irritable

• Anxious or tearful

• Foggy or detached

• Physically swollen or sore

Hormones affect the brain as much as the body. Be kind to yourself. Your emotional response is not a weakness — it’s a totally normal part of this process.

📖 Read next: Coping with IVF Side Effects

Every IVF protocol is slightly different — but the goal is always the same: to support your body in creating the best possible chance of pregnancy.

Medications can be intense, but they’re temporary. Knowing what to expect, and why each one matters, can help you feel more informed and in control.