How do Mounjaro and Trulicity work?
Mounjaro (tirzepatide) is a dual GLP-1 and GIP receptor agonist that mimics two gut hormones to boost insulin release, slow digestion, and reduce appetite. Trulicity (dulaglutide) is a GLP-1 receptor agonist only, targeting one hormone for similar effects but less potently on appetite and insulin sensitivity.[1][2]
Weight loss results head-to-head
In the SURPASS-2 trial, Mounjaro at 15mg led to 12.6kg average weight loss over 40 weeks versus 6.2kg for Trulicity 1.5mg in patients with type 2 diabetes. Non-diabetic trials like SURMOUNT show Mounjaro achieving up to 22.5% body weight reduction at 72 weeks, outpacing Trulicity's typical 5-10% in similar groups.[3][4]
Blood sugar control comparison
Mounjaro reduces A1C by 2.0-2.5% at highest doses, compared to Trulicity's 1.4-1.6%. Head-to-head data confirms Mounjaro's edge, with more patients reaching A1C under 7% (86% vs 80%).[3]
Dosing schedules and administration
Both are weekly subcutaneous injections via prefilled pens. Mounjaro starts at 2.5mg (titrate to 15mg max); Trulicity at 0.75mg (up to 4.5mg). Mounjaro requires faster titration, increasing nausea risk early on.[1][2]
Side effects patients report most
Gastrointestinal issues dominate: nausea (12-18% for Mounjaro vs 12-20% for Trulicity), vomiting, diarrhea. Mounjaro has higher early dropout rates from GI intolerance but similar long-term profiles. Both carry black-box warnings for thyroid tumors in rodents; pancreatitis and gallbladder risks apply to each.[5][6] Heart benefits are stronger with Trulicity (proven CV risk reduction), while Mounjaro shows promise but lacks full CVOT data yet.[7]
Cost and insurance coverage
Mounjaro lists at $1,069/month (15mg); Trulicity at $987 (4.5mg) before discounts. With coupons, both drop under $1,000, but coverage varies—Mounjaro often needs prior authorization for weight loss, while Trulicity is more established for diabetes. GoodRx prices: Mounjaro ~$950, Trulicity ~$850.[8]
Who makes them and patent timelines
Eli Lilly manufactures both. Mounjaro's key patents expire around 2035-2036; Trulicity's in 2029-2031, opening earlier biosimilar paths.[9][10]
[1] Mounjaro prescribing information, Eli Lilly. https://pi.lilly.com/us/mounjaro-uspi.pdf
[2] Trulicity prescribing information, Eli Lilly. https://pi.lilly.com/us/trulicity-uspi.pdf
[3] SURPASS-2 trial, NEJM 2021. https://www.nejm.org/doi/full/10.1056/NEJMoa2107519
[4] SURMOUNT-1 trial, NEJM 2022. https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
[5] FDA labels comparison. https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/215866s000lbl.pdf
[6] Ibid.
[7] REWIND trial for Trulicity, Lancet 2019. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(19)31149-3/fulltext
[8] GoodRx pricing data, accessed Oct 2024. https://www.goodrx.com
[9] DrugPatentWatch.com - Trulicity patents. https://www.drugpatentwatch.com/p/tradename/TRULICITY
[10] DrugPatentWatch.com - Mounjaro patents. https://www.drugpatentwatch.com/p/tradename/MOUNJARO