Background and AimsA limited number of randomized controlled trials (RCTs) have examined the use of lipid emulsions (LEs) of different compositions in home parenteral nutrition (HPN), and there are very few data on the long-term use of omega-3 (n-3) polyunsaturated fatty acids (PUFAs). The study´s objective was to assess safety and tolerability of an n-3 PUFA-enriched LE in adult patients suffering from chronic intestinal failure (CIF) requiring long-term HPN. MethodsIn this prospective, randomized, controlled, double-blind, multicentre, international clinical trial, which was conducted at eleven sites, adult patients in need of HPN including lipids received either the investigational product, an n-3 PUFA-enriched medium/long-chain triglyceride (MCT/LCT) LE, or the reference product, a standard MCT/LCT LE, for an average duration of eight weeks. The primary outcome was the sum of changes of liver function parameters (total bilirubin, aspartate transaminase and alanine transaminase) from baseline to final visit. Secondary objectives included fatty acid pattern in plasma and red blood cells (RBCs) and triene:tetraene ratio in plasma. Results74 patients were enrolled up to premature study termination. Liver function parameters showed no clinically relevant differences between study groups and remained within normal ranges. The n-3 PUFAs EPA and DHA increased in plasma and RBCs in the Lipidem group and were higher in the Lipidem group than the reference group at the end of the study resulting in an increased n-3-index in RBCs with Lipidem. Average n-3-index was >8. The plasma triene:tetraene ratio decreased in both groups. ConclusionThis study is one of the largest comparing two LEs in the complex setting of HPN treatment of adult patients. Although it has been early terminated its results considerably contribute to the evidence on safety and efficacy of longer-term use of LEs in HPN treatment. The n-3 PUFA-enriched LE Lipidem was safe and well-tolerated, particularly in terms of liver function. Lipidem provided an additional supply of n-3 PUFAs and led to positive changes in fatty acid profiles of plasma and RBCs. The n-3-index was in the desirable range at the end of the study in patients receiving Lipidem. There was no evidence of essential fatty acid deficiency with Lipidem. ClinicalTrials.gov IdentifierNCT03282955 Trial RegistrationEudraCT Number: 2015-000849-23