Bone & metabolism
Raloxifene
A selective oestrogen receptor modulator (SERM) — A bone-protecting drug for post-menopausal osteoporosis, with a breast-risk benefit but a clot caution.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
What it is
Raloxifene is used to prevent and treat osteoporosis in post-menopausal women, reducing the risk of spinal fractures, with a secondary benefit of lowering breast-cancer risk in some women.
How it works
As a selective oestrogen receptor modulator it acts like oestrogen on bone — helping maintain bone density — while acting against oestrogen in breast tissue, which underlies its breast-protective effect. Its oestrogen-like effect on the clotting system is what drives its main risk.
In practice
In practice raloxifene is an option for post-menopausal osteoporosis, particularly to reduce spinal (vertebral) fractures, and it has the added benefit of reducing the risk of oestrogen-receptor-positive breast cancer, which can make it attractive for women at higher breast-cancer risk. Its trade-offs shape who it suits: like other SERMs and oestrogen, it increases the risk of blood clots, so it is avoided in women with a clot history or prolonged immobility (and stopped before major surgery or long travel), and it does not relieve menopausal flushes — indeed it can worsen them. It has little effect on hip-fracture risk compared with some other agents, so the choice depends on the individual fracture pattern and risk profile. It is, of course, only used after the menopause.
Examples
Practical use
How to take it & use it well
- Raloxifene is a tablet taken by mouth, usually once a day, to treat and prevent osteoporosis in women after the menopause.
- It can be taken at any time of day, with or without food, and at around the same time each day.
- Take adequate calcium and vitamin D as advised, since the medicine works best with good bone nutrition.
- If you will be immobile for a long period, such as after surgery or on a long journey, tell your team, as the clot risk rises.
- Keep taking it long term as advised, even though you cannot feel it working.
- Report any leg swelling or pain, chest pain or sudden breathlessness urgently, as these can signal a clot.
Common uses
- Prevention and treatment of post-menopausal osteoporosis (especially vertebral fractures)
- Reduction of breast-cancer risk in some higher-risk post-menopausal women
Monitoring
- Bone protection and fracture risk over time
- Clot risk factors and immobility
- Menopausal symptoms
Weighing it up
Advantages & disadvantages
Advantages
- Strengthens bone and reduces the risk of spine fractures in post-menopausal osteoporosis.
- Can reduce the risk of certain types of breast cancer in some women.
- Does not stimulate the womb lining the way some hormone treatments do.
- Taken as a simple once-daily tablet.
Disadvantages
- Increases the risk of blood clots in the legs and lungs.
- Can cause or worsen hot flushes.
- May cause leg cramps.
- Not effective for reducing hip fractures in the same way as some other treatments.
- Must be paused during long periods of immobility because of the clot risk.
Key safety principles
What to watch for
- Increased risk of blood clots — avoid with a clot history; stop before prolonged immobility, major surgery or long travel.
- Does not relieve and may worsen menopausal hot flushes.
- Less effect on hip fracture than some alternatives; used only after the menopause.
Key interactions
What to avoid or check alongside
- Combining with other medicines that raise clot risk, such as some hormone treatments, adds to the danger of thrombosis.
- Can reduce the effect of warfarin, so anticoagulation may need monitoring.
- Bile-acid binders such as colestyramine reduce its absorption and should be separated in time or avoided.
- Tell your team about all medicines so interactions affecting clotting or absorption can be checked.
Patient & carer advice
- Tell us about any history of blood clots, and stop it if you will be immobile for a long period
- It will not help hot flushes and may make them worse
- It protects your bones and, for some women, lowers breast-cancer risk
Use with
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Dose and risk decisions for this class often depend on renal function, weight or bleeding/stroke risk. These tools help:
Answers
Raloxifene: frequently asked questions
How does raloxifene help my bones?
Raloxifene is a selective oestrogen receptor modulator that acts on bone like oestrogen, helping to maintain bone strength and reduce the risk of spine fractures after the menopause.
Why does raloxifene increase clot risk?
Like some hormone-related treatments, raloxifene raises the risk of blood clots in the legs and lungs. It is usually paused during long periods of immobility, and you should report leg swelling, chest pain or breathlessness urgently.
Can raloxifene reduce my breast cancer risk?
In post-menopausal women, raloxifene can reduce the risk of certain hormone-sensitive breast cancers. Your team can explain whether this benefit is relevant to you.
Will raloxifene help my menopausal hot flushes?
No. Raloxifene does not relieve hot flushes and can sometimes make them worse, so it is not used as a treatment for menopausal symptoms.
Should I take calcium and vitamin D with raloxifene?
Yes, usually. Good calcium and vitamin D intake helps the medicine protect your bones. Your team will advise whether you need supplements alongside it.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
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