Study Finds Lilly’s Tirzepatide Reduces A1C and Body Weight


After a 40-week treatment plan, a study conducted by Eli Lilly and Company found that their new medication, tirzepatide, significantly reduced A1C and body weight in adults with Type 2 diabetes. Participants who used the highest dose of tirzepatide reduced A1Cs by 2.07% and body weight by 11%; about 50% of patients in this study achieved an A1C of less than 5.7%.

Tirzepatide “is a once-weekly dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist that integrates the actions of both incretins into a single novel molecule.” In other words, tirzepatide works by decreasing food intake and increasing energy output which work in tandem to generate weight loss and regulate blood glucose levels. This also marks the first ever dual GIP-GLP combo drug used for Type 2 treatment.

The study observed that each of the tirzepatide doses led to lower A1Cs and reducded body weight. Lilly reported the following:

  • A1C reduction: -1.75% (5 mg), -1.71% (10 mg), -1.69% (15 mg), -0.09% (placebo)
  • Weight reduction: -6.3 kg (5 mg), -7.0 kg (10 mg), -7.8 kg (15 mg), -1.0 kg (placebo)
  • Percentage of participants achieving A1C <7%: 81.8% (5 mg), 84.5% (10 mg), 78.3% (15 mg), 23.0% (placebo)
  • Percentage of participants achieving A1C <5.7%: 30.9% (5 mg), 26.8% (10 mg), 38.4% (15 mg), 1.4% (placebo)”

During this study, no extreme lows (54 mg/dL or below) occurred. However, some side effects have been reported while using tirzepatide, such as nausea, diarrhea, vomiting, and constipation.

Currently, tirzepatide is in phase 3 development for blood glucose management in adults with Type 2 diabetes. Phase 3 included 478 random study participants from the United States, Mexico, India, and Japan; patients were either given 5 mg, 10 mg, or 15mg of tirzepatide or a placebo (no treatment) in a 1:1:1:1 ratio during a 40-week period. This was done in order to demonstrate that using tirzepatide, especially higher doses of the medication, resulted in a greater outcome for A1C and body weight reductions opposed to no treatment.

“We are impressed by these initial results showing how tirzepatide performed in people with a relatively short duration of diabetes,” said President of Lilly Diabetes, Mike Manson. “We look forward to seeing more results in people who are later in the course of diabetes in future studies from our robust SURPASS clinical trial program.”

Further data about the SURPASS clinical trial will be presented at the American Diabetes Association Scientific Sessions later this year.

WRITTEN BY Makaila Heifner, POSTED 01/08/21, UPDATED 01/08/21

Makaila was diagnosed with Type 1 diabetes at 16 months old. Before joining the Beyond Type 1 team in 2019, she worked at several diabetes camps, including Camp Leo and DYF. Makaila earned her BA in Global Studies and a minor in Public Policy from the University of California, Berkeley. When she isn’t editing articles, Makaila is a fan of soup, public radio, and live music. Check her out on Instagram: @makailaheifner