Tirzepatide lowers blood pressure so much it can go too low

Tirzepatide and semaglutide have become two of the most widely used medicines for type 2 diabetes and obesity, taken by huge numbers of people for months or years at a time. Both conditions travel with raised cardiovascular risk, so what these drugs do to blood pressure matters well beyond the number on the scales. Yet their blood pressure related safety profiles have remained unclear, with hypertension and hypotension events scattered across dozens of individual trials. This review set out to pull that safety data together and ask whether the two drugs behave the same way.

The researchers searched PubMed, Scopus, Web of Science, Embase, CENTRAL and ClinicalTrials.gov from inception to 26 September 2025. They gathered 32 randomised controlled trials that together enrolled 47,332 participants being treated for type 2 diabetes or obesity. For each drug they pooled the treatment-emergent adverse events related to high blood pressure and to low blood pressure, expressing the results as risk ratios using a random-effects model. Subgroup analyses then examined whether dose changed the picture.

Tirzepatide was associated with a markedly lower risk of hypertension-related events, a risk ratio of 0.40. The flip side was a 2.45 times higher risk of hypotension-related events, rising to 2.58 times at higher doses. Semaglutide looked far more neutral: its associations with hypertension-related events (risk ratio 0.81) and hypotension-related events (risk ratio 1.39) were both non-significant, although the authors noted potential protective signals in high-dose subgroups. In short, one drug moved blood pressure hard in both directions while the other barely registered.

The finding sharpens a distinction that single trials could not: two drugs often discussed interchangeably appear to carry different blood pressure profiles. The authors argue the results support individualised treatment decisions based on a person's baseline blood pressure and cardiometabolic risk. What the analysis cannot say is why the drugs differ, or whether the excess hypotension events with tirzepatide translate into meaningful harm in daily life. It also pools adverse event reports from trials designed for other endpoints, so studies built specifically around blood pressure would strengthen the case.

If you or someone close to you takes one of these medicines, this is a reason to think of blood pressure as part of the package rather than a side story. Tirzepatide's association with fewer hypertension events may be welcome news for people who start out with high blood pressure, while its raised risk of hypotension events, particularly at higher doses, is worth being aware of. Semaglutide's more neutral profile is itself useful information. None of this replaces the judgement of the prescriber who knows your own numbers.