OsmoLax Relief Clinical Evidence

The active ingredient in OsmoLax Relief, macrogol, has been clinically tested in multiple trials in adults and children with constipation.1,2 These studies have shown that macrogol can assist in the effective treatment of constipation and is well tolerated by both adults and children.1,2 Macrogol is generally more effective than lactulose.1 The evidence has also shown that macrogol without salts (electrolytes), such as OsmoLax Relief, is as effective as those with added salts, but tends to be easier to take and so should be tried first.1,2

One clinical study3 compared macrogol* without salts to macrogol with added salts. It was found that there was no difference in terms of effectiveness and side effects. 85% of patients in the group taking the macrogol product without salts were willing to continue treatment compared to 63% in the group taking the macrogol product with added salts, because of the salty taste of the latter.

In a study which compared macrogol without salts to macrogol with salts in children, 43% of children rated the taste of macrogol without salts as good or very good compared to only 2% in the group taking macrogol with added salts. There was no difficulty in giving macrogol without salts in 96% of children compared to 52% of children taking macrogol with added salts.4


1. Katelaris et al. BMC Gastroenterology (2016) 16:42

2. Krassas et al. Polyethylene glycols with or without electrolytes for constipation in children: A network meta-analysis Abstract 67 GP16

3. Sienela et al. Comparison of polyethylene glycol with and without electrolytes in treatment of constipation in elderly institutionalised patients.
Drugs Aging 2009:26 (8): 703-713

4. Savino F et al: Efficacy and tolerability of PEG -only laxative on faecal impaction and chronic constipation in children. A controlled double blind randomised study vs a standard PEG-electrolyte laxative. BMC Paediatrics 2012. 12:178 doi:10.1186/1471-2431-12-178

* This study was done with macrogol 4000 which is a similar product to macrogol 3350.

Always read the label. Follow the directions for use. If symptoms persist, talk to your health professional.