The fulvestrant injection: two large injections every month

Fulvestrant is given as two injections at each visit, one into the muscle of each buttock. Each injection comes in its own ready-filled syringe and holds a fairly large amount of thick, oily liquid, which is why it is given slowly, usually over one to two minutes per side. A nurse gives the injections in a clinic or day care unit, and the injections themselves take only a few minutes, although the whole visit can be longer if blood tests or a doctor's review are planned for the same day. In the first month there is an extra dose: you have injections on the first day, again two weeks later, and again two weeks after that. From then on the injections are given once every four weeks for as long as the treatment is working and suits you. Most people feel pressure and a dull ache while the medicine goes in, followed by soreness or stiffness for a day or two. Bruising and a small firm area under the skin are common. The nurse chooses a spot in the upper, outer part of the buttock, away from the large nerve that runs down the back of the leg. If you take blood thinners or have a low platelet count, tell your team before the first dose, because injections into muscle can bleed more in these situations.

Two injections, one each side

The full dose is split between two syringes, so each buttock gets one injection at every visit.

An extra dose at the start

The first month has three visits to raise medicine levels quickly, then visits settle to every four weeks.

Slow is kinder

Giving the thick liquid slowly makes the injection more comfortable and reduces soreness afterwards.

Fulvestrant is often described as a gentle treatment, and for many people it is. It is still fair to say the injections are not pleasant.

They can hurt

The volume is larger than most injections, and many people describe a deep ache as the liquid goes in. For most, this is brief and bearable, but it is real.

Visits are a commitment

Treatment means a trip to hospital every four weeks, sometimes for a long time. Travel, time off work and waiting can be tiring for you and for the family member who comes with you.

It cannot be taken at home as a tablet

Fulvestrant only works as an injection into muscle, so it cannot be swapped for a tablet version.

What this page cannot tell you

It cannot tell you exactly how your hospital runs its injection clinic or whether fulvestrant is the right choice for you. Your team can explain both.

Fulvestrant is often only one part of the treatment plan, and the monthly visit is a convenient time to organise the rest.

Tablets taken with fulvestrant

Many people take a CDK4/6 inhibitor tablet with fulvestrant. Others may take alpelisib or capivasertib. Blood tests for these medicines are often done at the injection visit.

Injections that stop the ovaries

Women who have not been through menopause, and some men, need a separate hormone injection, often under the skin of the belly, so that fulvestrant can work properly.

Bone-strengthening treatment

If the cancer has spread to the bones, a drip or injection to protect them may be given on a similar schedule.