Ozgoli 2017.

Study characteristics
Methods	Randomised controlled trial
Participants	Setting: Shohada Hospital, Ghochan, Iran. Timing from trial registration ‐ September to December 2013 Inclusion criteria: Iranian; speak the Persian language; normal vaginal delivery between 37 and 42 weeks, ability to breastfeed, with postpartum pain of degree 4 or more on numeric scale (not specified) and requiring narcotics. Women aged from 20 to 30 years. Women with uterine cramp pain (author email 6 January 2020) Exclusion criteria: Instrumental or caesarean birth or previous caesarean birth, epidural or spinal anaesthetic, smoking or drug abuse, chronic disease including hypertension, diabetes, heart disease or infectious disease. Allergy to anise. Women with pain from episiotomy (author email 6 January 2020).
Interventions	Following initial pain assessment, women were randomised into 1 of 2 groups: Experimental intervention: The samples were given an Anise oral capsule containing 60 mg of dried extracts of anise (produced in Shahid Beheshti pharmacy faculty), 1 hour after delivery then every 6 hours for 24 hours. N = unknown Control/comparison: the samples were given a mefenamic acid oral capsule 250 mg, 1 hour after delivery then every 6 hours for 24 hours. N = unknown
Outcomes	Pain, however reported by the author
Notes	96 women randomised, N per group was not reported The 2 groups were matched in the number of parity and intensity of the pain before intervention. Funding: Vice Chancellor for research of Shahid Beheshti University of Medical Sciences(SBUMS) Declaration of interest: none stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Authors state: "Capsules are put in the bar coded packets and given to the patients randomly"
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not stated
Blinding of participants and personnel (performance bias) All outcomes	Low risk	This research is a double‐blind study in which researcher and patients are not aware about prescribed capsules
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not stated
Incomplete outcome data (attrition bias) All outcomes	Low risk	Translation states 96 women recruited and randomised, abstract and translation state 96 women included in the trial
Selective reporting (reporting bias)	High risk	No published protocol. Trial registration retrospective
Other bias	Unclear risk	Abstract only in English, full text required translation