Study	Reason for exclusion
Abu Hashim 2013	Participants had pathology ‒ endometrial hyperplasia
Adiguzel 2017	This is not an RCT. Women were offered the different treatments and were free to choose their option
Apter 2016	The comparison was relevant LNG‐IUS versus Etonorgestrel implant, participants needed contraception and did not have heavy menstrual bleeding
Buyuktuna 2016	This is not an RCT
Cameron 1987	The intrauterine system used in this trial has been off the market since 2001
Ghazizadeh 2011	Although the study was described as random, the authors stated that participants were allowed to choose their treatment
Gupta 2006	Relevant comparison but participants were able to choose their treatment and were not randomised
Janssen 1999	This randomised double‐blind trial compared the effects of a multiload intrauterine device releasing 0.0 (control group), 1.5, 3.0 and 6.0 µg of 3‐ketodesogestrel daily on menstrual blood loss but 22% of the participants did not have heavy menstrual bleeding
Karacaoglu 2001	This study was written in Turkish and translated by Dr Ahmet Metin Gulmezoglu. There is no indication that it was randomised
Karimi‐Zarchi 2013	Participants had pathology ‒ endometrial hyperplasia
Kucuk 2008	Quasi‐randomised trial ‒ "by a predefined application order"
Lahteenmaki 1998	This study did not measure any of the review's outcomes
Lee 2013	Observational cohort study ‒ participants were not randomised
Mawet 2014	The comparison is between two different brands of the same product (LNG‐IUS 20 µg daily)
McMillan 1998	Unknown characteristics of study
McMillan 2005	Unknown characteristics of study
Milsom 1991	This study compared flurbiprofen (an NSAID), tranexamic acid and LNG‐IUS in 35 women with menorrhagia. The first 20 consecutive women were treated with LNG‐IUS and the remaining 15 women were randomised to either flurbiprofen or tranexamic acid in a cross‐over design. The reduction in menstrual blood loss was compared between all treatments. There was no randomization
Rogerson 1999	This trial experienced difficulties in recruiting patients and was stopped
Romer 2000	This study was a controlled comparative study with equal numbers of patients in each group, endometrial ablation and LNG‐IUS. There is no indication that it was randomised
Tosun 2014	Substantially biased study with large imbalance in dropouts, so final results not informative

LNG‐IUS: levonorgestrel‐releasing intrauterine system
NSAID: non‐steroidal anti‐inflammatory drug