Don't think they are aspirin based?
This is from NHS website on heavy periods
Non-steroidal anti-inflammatory drugs (NSAIDs) are also used to treat menorrhagia as a second choice of treatment if LNG-IUS is not appropriate. NSAIDs have been shown to reduce blood loss by 20-49%, and are taken in tablet form from the start of your period (or just before) and for the duration of bleeding, until it has stopped. As with tranexamic acid, treatment should be stopped if your symptoms have not improved within three months.
The NSAIDs that are recommended as a treatment for menorrhagia are mefenamic acid (500mg three times daily), naproxen (500mg as the first dose, then 250mg every six to eight hours), and ibuprofen (400mg three or four times daily).
NSAIDs work by reducing your body's production of a hormone-like substance, called prostaglandin, which is linked to heavy periods. NSAIDs are also painkillers but they are not a form of contraceptive. However, if necessary, they can be used in conjunction with the combined oral contraceptive pill (see below).
Common side effects include indigestion and diarrhoea.
NSAIDs can be used for an indefinite number of menstrual cycles, as long as they are relieving symptoms of heavy blood loss and are not causing significant adverse side effects. However, if NSAIDs are found to be ineffective, treatment should be stopped after three months.