This information is for people who have heavy periods. It tells you about tranexamic acid, a treatment used for heavy periods. It is based on the best and most up-to-date research.
Does it work?
Yes. About 6 out of 10 women who take tranexamic acid get lighter periods. 
This drug works better than non-steroidal anti-inflammatory drugs (NSAIDs) and some treatments that affect the level of hormones in your body. But, unlike NSAIDs, tranexamic acid will not relieve any pain you get with your periods.
What is it?
Tranexamic acid is a drug that reduces bleeding. It works by making the blood in your womb more likely to form clots. These clots stop the flow of blood from the lining of your womb.
You take a tablet three or four times a day during your period. The brand name for tranexamic acid is Cyklokapron. Your doctor can prescribe this treatment, or you can buy it over the counter from a pharmacy. Brand names for the over-the-counter versions are Cyklo-F and Femstrual.
The National Institute for Health and Clinical Excellence (NICE), the government body that decides which treatments should be available on the NHS, says tranexamic acid is one of the first treatments women with heavy periods should consider. 
How can it help?
If you take tranexamic acid during your period, there is a good chance that your period will be lighter. About 6 out of 10 women who take the drug lose less blood. 
You'll probably feel able to do more during your period. One study found that women taking tranexamic acid had a better social life and sex life than women who took a dummy treatment (a placebo). 
Tranexamic acid might work better at making periods lighter than other drugs used to treat heavy periods. Some fairly small studies suggest it may work better than non-steroidal anti-inflammatory drugs (NSAIDs), a drug called etamsylate, and progestogen tablets.   
How does it work?
Tranexamic acid makes the blood in your womb more likely to clot. This reduces the amount of blood you lose during your period.
Can it be harmful?
One-third of women who take tranexamic acid feel queasy and get leg cramps. 
In the past, there was concern that the drug could cause blockages in important blood vessels. This is called thromboembolism. But a large study over 19 years found that the problem was no more common in people taking tranexamic acid than in other people. 
How good is the research on tranexamic acid?
There is good evidence that tranexamic acid helps women with heavy periods.  
The research also shows that tranexamic acid might work better than some other drug treatments for heavy periods ( NSAIDs, etamsylate, and progestogen tablets), but not as well as surgery to remove the womb lining.     
We know this from reviews of the research that have looked at lots of good-quality studies (called randomised controlled trials).