Haematology
Tranexamic acid
An antifibrinolytic — Reduces heavy bleeding — widely used for heavy periods, surgery and trauma.
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.
Quick answer
What is Tranexamic acid?
Tranexamic acid reduces excessive bleeding by helping the body hold clots in place. It is widely used for heavy menstrual periods and to reduce blood loss in surgery, dental work in bleeding disorders, and serious injury.
- How it works: When the body forms a clot, it also starts to break it down (fibrinolysis).
- In practice: In practice tranexamic acid is a simple, effective treatment to reduce bleeding: taken as tablets for heavy menstrual periods (only on the days of bleeding), and given in surgery, dental procedures in people with bleeding disorders, and major trauma to cut blood loss and save lives.
What it is
Tranexamic acid reduces excessive bleeding by helping the body hold clots in place. It is widely used for heavy menstrual periods and to reduce blood loss in surgery, dental work in bleeding disorders, and serious injury.
How it works
When the body forms a clot, it also starts to break it down (fibrinolysis). Tranexamic acid blocks that breakdown process, so clots that have formed at a bleeding point last longer and bleeding is reduced. The same clot-stabilising action is why it must be used cautiously where unwanted clots are a risk.
In practice
In practice tranexamic acid is a simple, effective treatment to reduce bleeding: taken as tablets for heavy menstrual periods (only on the days of bleeding), and given in surgery, dental procedures in people with bleeding disorders, and major trauma to cut blood loss and save lives. The practical themes centre on clot risk and appropriate use. Because it works by stabilising clots, it is used with caution — or avoided — in people with a history of blood clots (DVT or pulmonary embolism), and care is taken alongside combined hormonal contraception and other clot risk factors. It is renally cleared, so the amount is reduced in kidney impairment. For heavy periods it is a non-hormonal option that does not affect fertility or cycle, which many find attractive, but persistent heavy bleeding still warrants investigation for an underlying cause. It is not for bleeding that needs a clot to be broken down (such as some kidney bleeding) without advice.
Examples
Practical use
How to take it & use it well
- For heavy periods, start it once your period begins and take it for the heaviest days as directed, rather than throughout the whole month.
- Swallow the tablets with water, and you can take them with or without food, which often helps if they upset your stomach a little.
- Tell your doctor before starting if you have ever had a blood clot, such as in the leg or lung, or have a condition that makes clots more likely, as it may not be suitable.
- If you miss a dose during your period, take it when you remember unless it is nearly time for the next, then carry on as normal without doubling up.
- Stop and seek urgent help if you develop signs of a clot, such as a painful, swollen leg, sudden breathlessness, chest pain, or changes in your vision.
- In hospital it is also given by injection during surgery or after serious injury to reduce bleeding, where it is closely supervised by the medical team.
Common uses
- Heavy menstrual bleeding (on bleeding days)
- Reducing surgical and dental bleeding
- Major trauma and some other bleeding situations
Monitoring
- Reduction in bleeding and any clot symptoms (calf/chest)
- Renal function where relevant
- Underlying cause of heavy bleeding if it persists
Weighing it up
Advantages & disadvantages
Advantages
- It noticeably reduces heavy menstrual bleeding for many women without affecting hormones or fertility.
- It is only needed on the heaviest days of a period rather than every day of the month.
- It is a hormone-free option, which suits women who cannot or prefer not to use hormonal treatments.
- Given in hospital, it helps control serious bleeding during surgery and after major trauma.
- It is taken by mouth for periods and is generally well tolerated.
Disadvantages
- It can occasionally cause stomach upset, such as nausea, diarrhoea or indigestion.
- It is not suitable for people with a history of blood clots or certain clotting conditions.
- It reduces bleeding but does not treat the underlying cause of heavy periods, which may still need investigating.
- Rarely it can cause disturbances of colour vision, which should be reported.
- It needs caution in kidney problems, where the amount may need adjusting under medical advice.
Key safety principles
What to watch for
- Use with caution or avoid in people with a history of blood clots (DVT/PE) or strong clot risk factors.
- Renally cleared — the amount is reduced in kidney impairment.
- For heavy periods, take it only on the days of bleeding; persistent heavy bleeding still needs assessment for a cause.
Key interactions
What to avoid or check alongside
- Used with the combined contraceptive pill, there may be a small added risk of clots, so your history should be reviewed.
- Other medicines that increase clotting risk, including some hormone treatments, should be considered before starting it.
- Certain clotting-factor treatments used for bleeding disorders should only be combined under specialist guidance.
- Tell your doctor about all your medicines and any history of clots, strokes or heart problems before using it.
- Caution is needed with medicines cleared by the kidneys if your kidney function is reduced.
Patient & carer advice
- For heavy periods, start it when bleeding begins and take it only on bleeding days
- Tell us if you have ever had a blood clot, or are at higher risk of one
- Report calf swelling/pain, breathlessness or chest pain straight away
Use with
Related clinical calculators
Dose and risk decisions for this class often depend on renal function, weight or bleeding/stroke risk. These tools help:
Answers
Tranexamic acid: frequently asked questions
Does tranexamic acid stop my period completely?
No, it reduces how heavy the bleeding is rather than stopping your period. Many women find their periods become much more manageable, but you will usually still have a period as normal.
Is it safe if I've had a blood clot before?
If you have had a blood clot, such as in the leg or lung, or have a clotting condition, tranexamic acid may not be suitable for you. Tell your doctor your full history so they can decide whether it is safe or suggest an alternative.
When in my cycle do I take it?
For heavy periods you usually start it when your period begins and take it during the heaviest days, not all month. Follow the specific instructions you have been given.
Does it affect my fertility or hormones?
No, tranexamic acid is a hormone-free treatment and does not affect your fertility. It works by helping blood clot more effectively to reduce bleeding, which is why it suits women who prefer to avoid hormonal options.
What warning signs should make me stop taking it?
Stop and seek urgent help if you notice signs of a clot, such as a painful or swollen leg, sudden breathlessness, chest pain, or new changes to your vision. These are uncommon but need prompt assessment.
Authoritative sources
Always verify against the source
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