Does Puregon need refrigeration?

This depends on the pen or cartridge and whether it has been opened, so check the leaflet in the box and your clinic's instructions.

How many injections come from one pen?

This depends on the prescribed dose and cartridge size. Your clinic nurse will explain how your specific pen is set up.

What if the injection site is sore afterwards?

Mild soreness or bruising is common. Contact your clinic if you notice spreading redness, warmth, or other signs of infection.

Does it interact with other medicines?

Tell your clinic about anything else you take, including over the counter medicines and supplements.

Follicle stimulating hormone (FSH) injection

Puregon

Also known as Follitropin beta, Follistim (same active ingredient, different brand name)

Written by Zayn Miah & R KhanomLast updated 17 September 2026Not clinically reviewed

Puregon is a lab-made form of follicle stimulating hormone, given by injection under the skin using a pen or syringe.

Why it may be used

It is used to stimulate the ovaries so that multiple follicles develop during an IVF cycle, aiming to allow more than one egg to be collected at retrieval.

Where it fits in a cycle

It is typically used during the stimulation phase, with the clinic setting the schedule and checking progress through scans and blood tests, adjusting the plan as the cycle goes on.

Side effects listed in the patient leaflet

Injection site reactions such as bruising or redness
Headache
Abdominal bloating or discomfort
Nausea
Breast tenderness
Mood changes
Ovarian enlargement during treatment

When to ring the clinic

•Rapidly worsening abdominal swelling
•Severe abdominal or pelvic pain
•Shortness of breath
•Passing noticeably less urine
•Sudden weight gain or signs of infection at an injection site

Questions people ask

Does Puregon need refrigeration?: This depends on the pen or cartridge and whether it has been opened, so check the leaflet in the box and your clinic's instructions.
How many injections come from one pen?: This depends on the prescribed dose and cartridge size. Your clinic nurse will explain how your specific pen is set up.
What if the injection site is sore afterwards?: Mild soreness or bruising is common. Contact your clinic if you notice spreading redness, warmth, or other signs of infection.
Does it interact with other medicines?: Tell your clinic about anything else you take, including over the counter medicines and supplements.

Safety

This is general information, not medical advice, and does not replace guidance from your clinic.
Follow your own clinic's specific instructions for dose and timing.
The patient information leaflet in the box is the authoritative source for this medicine.
Tell your clinic about other medicines, allergies and medical conditions before starting treatment.

Sources

Patient information leaflets and product characteristics, electronic medicines compendium (emc). Link checked 17 September 2026.
IVF: what is IVF and how does it work?, HFEA (UK fertility regulator). Link checked 17 September 2026.

Written by patients, not clinicians. This page has not yet been reviewed by a named fertility professional, so it explains published guidance and points you to the original source instead of giving medical advice. It is not medical advice. Decisions about your treatment belong with your own clinic. Read our editorial policy and corrections policy.