VIP improved lung function in a 34-person study

VIP improved several measures of breathing and activity in a small study comparing it with a placebo, an inactive treatment used for comparison. The study used random assignment, and neither participants nor the people assessing them knew which treatment each person received. It enrolled 34 people with COPD and assessed lung function, walking distance, and quality of life. DOI

The amount of air participants could force out in the first second of a breath improved by 0.107 liters compared with placebo. Vital capacity, the total amount of air exhaled after a full breath in, improved by 0.155 liters compared with placebo. Distance covered during a six-minute walking test increased by 24.1 meters in the VIP group, while it decreased by 8.6 meters in the placebo group. Two questionnaires also showed greater improvement in quality of life with VIP. DOI

The same report linked VIP treatment to lower production of IL-8 and TNF, two proteins that help drive inflammation. Laboratory work also found reduced activity in several proteins that switch on inflammation-related genes. The limitation is the 34-person sample and the lack of information about lasting benefits in the supplied abstract, which leaves the longer-term importance of these changes unsettled. DOI

The COPD findings have an earlier clinical precedent, but the reports should not automatically be counted as independent confirmation. A 2006 meeting abstract reported improved six-minute walking performance and quality of life with inhaled VIP in COPD. The supplied records do not establish whether that report and the 2026 paper describe separate patient groups. DOI+1

Earlier laboratory research also supports an effect on lung inflammation. In 2020, a study in mice and immune cells found that VIP reduced activity in an inflammatory alarm system during experimentally induced lung injury. That helps explain why researchers might test VIP in lung disease, but it does not establish a patient benefit on its own. Elsevier

Human evidence has been less straightforward. A 2022 randomized trial tested aviptadil, a synthetic version of VIP, in 196 critically ill people with COVID-19 respiratory failure, meaning they could not breathe adequately. The main measure was whether patients were alive and free of respiratory failure at day 60, and the trial did not establish a benefit on that combined outcome. A separate analysis found higher odds of survival with aviptadil. The limitation is that severe infection-related lung failure and long-term airflow obstruction are different settings, so the results do not directly confirm or cancel each other. DOI+1

Lower VIP levels appeared more often than higher levels in the studies reviewed, but they did not amount to a reliable disease test. The 2026 review examined VIP as a possible biomarker, a measurable feature that could help identify a disease or track its course, in multiple sclerosis, or MS, an immune-related disease. It included seven human studies published between 1984 and 2024. PubMed

Most studies reported lower VIP concentrations in blood or the fluid surrounding the brain and spinal cord than in healthy people. The differences were not consistently clear, and the studies used methods that made direct comparisons difficult. The reviewers therefore described the findings rather than combining them into one numerical estimate. PubMed

One recent study suggested some ability to distinguish patients from healthy people using blood VIP measurements, but the review judged the overall evidence limited. Studies of inherited differences in the VIP gene found no association with the chance of developing MS. The limitation is that most studies measured people at one point in time, leaving little evidence that VIP predicts what happens next. This review examined measurement, not whether giving VIP improves MS. PubMed

VIP helped the intestine move fat after the meal-absorption period, but blocking VIP did not change the response during meal absorption. The researchers tested GLP-2, a gut hormone that helps regulate intestinal fat handling, with and without a compound that blocks VIP activity. They studied rats and collected intestinal lymph, fluid that carries absorbed fat away from the gut, to measure fat output. PubMed

The blocking compound acted on VIP receptors, the cell-surface docking sites through which VIP sends instructions. Blocking those receptors reduced the extra fat output caused by GLP-2 after the meal-absorption period. It did not change GLP-2's effect while the animals were absorbing a meal. The finding places VIP in one part of the hormone's fat-handling process rather than showing that it controls every stage. PubMed+1

This adds a different function to earlier evidence about VIP in the gut. A 2015 mouse study found that animals missing VIP had fewer mucus-producing cells and a leakier intestinal barrier, while supplying VIP reversed the defect. The newer rat experiment instead examined the movement of fat already held in the intestine after meal absorption. The limitation is that it tested a pathway in rats, not weight change or a treatment benefit in people. PubMed+1

The three reports answer different questions, which matters more than their shared focus on VIP. The COPD study compared a treatment with placebo, while the MS review evaluated measurements associated with disease. The rat experiment tested where VIP fits into a hormone-controlled process. DOI+2

Report	Design and sample	Main finding
COPD	Randomized placebo comparison in 34 people	Better lung function, walking distance, and quality-of-life scores. DOI
MS	Review of seven human studies	VIP levels were often lower, but evidence for a useful test remained limited. PubMed
Gut fat handling	Blocking experiment in rats	VIP supported fat output after meal absorption, but not during it. PubMed

This information is for research only. Not intended for human use.

Lower levels in a patient group do not by themselves establish that replacing VIP would improve the disease. Likewise, blocking a pathway in rats does not establish a benefit from adding VIP in people. The COPD report provides the most direct treatment comparison among these three papers, but its small sample limits how far the finding can be extended. For a wider view of the evidence, explore the VIP research summary. DOI+2

The supplied COPD abstract does not establish whether the gains persisted or reduced hospital admissions, and the relationship to the earlier COPD report remains unclear. The MS review leaves open whether VIP can predict future disease changes rather than simply differ between groups. The rat experiment leaves open whether the same fat-handling mechanism has a meaningful effect in humans. DOI+3