Tirzepatide lowers uric acid in a SURMOUNT-1 post hoc analysis

A post hoc analysis of the SURMOUNT-1 trial reports that tirzepatide, sold as Zepbound and Mounjaro, lowered serum uric acid levels over 72 weeks of treatment, while a separate set of case reports describes the opposite pattern in some patients during the first months on the drug ^[1][2].

In the SURMOUNT-1 analysis, people taking tirzepatide saw uric acid fall by 0.69 to 0.95 mg/dL at 72 weeks, depending on the dose, compared with a 0.18 mg/dL drop in the placebo group ^[1]. The effect held up regardless of how high a person's uric acid was at the start of the study or what their body mass index was ^[1]. Researchers used mediation analysis, a statistical method that estimates how much of an effect is explained by another factor, and found that weight loss accounted for 72.7 percent of the drop in uric acid ^[1]. That leaves roughly a quarter of the effect unexplained by weight loss alone, suggesting the drug may act on uric acid through other pathways as well, though the source does not specify what those might be.

A separate report in AACE Endocrinology and Diabetes describes a different pattern: transient increases in serum uric acid and gout attacks in some patients shortly after starting tirzepatide or semaglutide ^[2]. These case reports describe flares occurring in the early months of treatment, a period that does not match the 72-week improvement seen in the SURMOUNT-1 data ^[1][2]. The sources do not say how common these early flares are or whether the same patients who saw early increases went on to see uric acid fall by 72 weeks.

Why it matters for patients

Uric acid buildup is linked to gout, a painful form of arthritis caused by crystal deposits in joints. The SURMOUNT-1 findings suggest that people on tirzepatide for weight management may see lower uric acid levels over time, which could matter for those with a history of gout or elevated uric acid ^[1]. But the case reports of early flares point to a possible short-term risk that runs counter to the longer-term trend ^[2]. Rapid weight loss itself has long been associated with uric acid shifts in some patients, and the sources here describe both a lowering effect over many months and a rise in the first weeks or months, which are not necessarily contradictory but do describe different time windows ^[1][2].

Patients who have gout or high uric acid and are considering or already taking tirzepatide or semaglutide may want to be aware that the two effects described in these sources happen on different timelines: a possible early increase, followed by a longer-term decrease. Nothing in the sources indicates that either finding changes the overall safety profile of these drugs, and neither source recommends any change in how the medications are prescribed or monitored.

What happens next

The sources do not give a timeline for further study, and it is not yet known whether regulators or professional societies will update prescribing guidance based on these findings. It is also not known from these sources how often the early uric acid spikes described in the case reports occur, or which patients are most likely to experience them. Larger studies designed specifically to track uric acid and gout outcomes over both the short and long term would help clarify how these two findings fit together.