Tsang 1987.

Methods	Randomisation method not stated Double‐blind placebo‐controlled trial with cross‐over design Losses to follow‐up: 4 Not ITT and no power calculation made
Participants	Canada 14 women aged 26–47 years with either a history of heavy menstrual bleeding or MBL > 80 mL/cycle (measured objectively) and regular menstrual cycles Exclusions: use of hormonal contraceptives or anti‐inflammatory drugs and use of IUCD
Interventions	Group 1: MFA 500 mg at onset of menses, then 250 mg 4 times daily for 3–5 days, n = 10 Group 2: placebo same dosage regimen, n = 10 Duration: 2 + 2 cycles
Outcomes	MBL (measured by alkaline haematin method)
Notes	Data not available at end of first cross‐over period so not suitable for pooling in a meta‐analysis.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated
Allocation concealment (selection bias)	Unclear risk	Unclear risk
Blinding (performance bias and detection bias) All outcomes	Low risk	Double blind
Incomplete outcome data (attrition bias) All outcomes	High risk	4/14 women lost to follow‐up, no ITT analysis
Other bias	Unclear risk	Nothing detected