Cimetidine

Studies of cimetidine measured 3 outcomes: jejunal pH, aqueous-phase lipid concentration and Bile acid precipitation.

Studies link cimetidine with gynecologic cancer.

Cimetidine has been studied in 2 papers since 1986: 1 trial and 1 observational study in people; 1 in the past year. The newest paper, Jan 23, 2026: “The Potential Impact of Histamine-2 Receptor Antagonists on Gynecologic Cancer Risk: A Population-Based Study of 23 Million Individuals”.

2 papers study it1 more mentions it4 findingsUpdated Jan 23, 2026

At a glance

The findings reach people, from one lab or study. 2 independent labs in 2 countries; 4 trials, none about aging, 1 with no results posted.

“associated with a reduction in bile acid precipitation (13.9 vs 33.1%, p less than 0.05)”

None of its findings points the other way.

1 study gave cimetidine to people and measured what changed.

What changed	Design	People	Source
down: Decreases bile acid precipitation13.9 vs 33.1%, p<0.05 up: Increases aqueous-phase lipid concentration10.4 vs 6.6 mmol/l, p<0.05 up: Increases jejunal pH6.6 vs 5.8, p<0.05	Randomized trialtwo weeks	9 peoplePatient cohorts	Gut, Jan 1, 1986

up: Increases aqueous-phase lipid concentration10.4 vs 6.6 mmol/l, p<0.05

up: Increases jejunal pH6.6 vs 5.8, p<0.05

Randomized trialtwo weeks

9 peoplePatient cohorts

Gut, Jan 1, 1986

Studies of cimetidine measured 3 outcomes: jejunal pH, aqueous-phase lipid concentration and Bile acid precipitation.

Jejunal pH

upin humans1

1 study

Cimetidine increases jejunal pH in humans (versus placebo, particularly during the third hour) (6.6 vs 5.8, p<0.05).
“On cimetidine mean pH rose, particularly during the third hour (6.6 vs 5.8, p less than 0.05)”
Human trialversus placebo, particularly during the third hourupper jejunumtwo weeksn = 9
Ileal resection: effect of cimetidine and taurine on intrajejunal bile acid precipitation and lipid solubilisation
GutJan 1, 1986

Studies link cimetidine with gynecologic cancer.

Gynecologic cancer

downin humans1

1 study

Cimetidine is linked with a lower risk of gynecologic cancer in humans.
“Individual H2RA agents showed protective effects in the overall population, with cimetidine demonstrating the broadest reduction.”
Humansfemales
The Potential Impact of Histamine-2 Receptor Antagonists on Gynecologic Cancer Risk: A Population-Based Study of 23 Million Individuals
Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive OncologyJan 23, 2026