Beyond Semaglutide: What Triple-Agonist Research Means for Health Systems Planning Obesity Care

Health systems have spent the last three years responding to demand for GLP-1 drugs. Many are still dealing with long prior authorization queues, changes in employer coverage, and rising pharmacy costs. Now, another wave of obesity treatments is approaching.

Eli Lilly plans to submit a Biologics License Application for retatrutide to the FDA in the first quarter of 2027. This once-weekly drug targets three hormone receptors, and its phase 3 results show weight loss in a range typically associated with bariatric surgery (Eli Lilly and Company, 2026b). For health system executives, pharmacy leaders, and clinical program directors, the next 12 to 18 months provide time to prepare budgets, care pathways, and formulary criteria ahead of an approval decision.

How a Triple Agonist Differs From Today’s Incretin Drugs

Semaglutide activates the GLP-1 receptor. Tirzepatide targets both GLP-1 and GIP receptors. Retatrutide adds a third target: the glucagon receptor. Glucagon receptor activity is thought to increase energy expenditure and promote fat oxidation in the liver. This may complement the appetite suppression provided by the other two pathways.

The first strong clinical evidence came from a 48-week phase 2 trial involving 338 adults with obesity. Participants receiving the 12 mg dose lost an average of 24.2% of their body weight (Jastreboff et al., 2023). Those results drew attention from formulary committees, but larger, longer trials were needed to see whether the benefits would hold up.

What the TRIUMPH Phase 3 Data Show

The phase 3 results have continued to show substantial weight loss. TRIUMPH-1 enrolled 2,339 adults with obesity or overweight and at least one weight-related health condition. Participants receiving 12 mg lost an average of 28.3% of their body weight at 80 weeks. Nearly half (45.3%) lost at least 30% (Eli Lilly and Company, 2026a).

Among participants with a starting BMI of 35 or higher who continued into a blinded extension, average weight loss reached 30.3% at 104 weeks. The 4 mg dose, which required only one dose increase, produced an average weight loss of 19.0% at 80 weeks.

Two additional trials, reported in July 2026, studied people with more complex health needs. In TRIUMPH-2, adults with type 2 diabetes lost up to 20.8% of their body weight at 80 weeks. Their A1C levels fell by up to 1.6 percentage points from a starting average of 7.7% (Eli Lilly and Company, 2026b).

In TRIUMPH-3, adults with severe obesity and established cardiovascular disease lost up to 22.6% of their body weight. The cardiovascular findings were inconclusive, however. The MACE-5 hazard ratio was 0.82, but its confidence interval included 1.0, indicating the trial did not demonstrate a clear reduction in cardiovascular events. Claims about those benefits will need to wait for dedicated studies.

The side-effect profile included familiar gastrointestinal symptoms and a less common concern. In TRIUMPH-1, nausea affected 42.4% of participants receiving 12 mg, compared with 14.8% receiving placebo. At that dose, 11.3% discontinued treatment due to adverse events, compared with 4.9% in the placebo group (Eli Lilly and Company, 2026a).

Dysesthesia, an abnormal or unpleasant skin sensation, occurred in 12.5% of the 12 mg group and 0.9% of the placebo group. This has not been a routine topic in incretin counseling. Lilly reported that most cases were mild to moderate and resolved during treatment. Even so, these symptoms will matter when clinicians choose doses, explain side effects, and plan follow-up.

The Budget Question Health Systems Can’t Defer

Payers and employers are already reconsidering coverage for existing GLP-1 drugs. KFF’s analysis of employer GLP-1 coverage found that 19% of firms with at least 200 workers covered these drugs for weight loss in 2025. Coverage rose to 43% among firms with at least 5,000 workers. Meanwhile, 64% of large firms said the drugs had moderately or significantly affected their prescription spending (KFF, 2025).

The International Foundation of Employee Benefit Plans reported that GLP-1s accounted for 6.9% of annual claims in 2023, rising to 11.4% in 2026 (International Foundation of Employee Benefit Plans, 2026). Retatrutide’s price has not been announced, but it will enter a market where benefits leaders are closely examining treatment costs.

Health systems face this pressure in two ways: as providers responding to patient demand and as self-insured employers covering treatment for their own workers. Budget planning needs to account for both.

The drug itself is only part of the expense. Dose-adjustment visits, side effect management, nutrition counseling, and lab monitoring add to the cost of care. These are the hidden costs that skew ROI evaluations when programs are approved based on drug price alone.

A model that accounts for each patient’s dose and clinical needs may help control total costs. Avoiding an automatic move to the maximum dose could prove as consequential as negotiating rebates.

Building the Clinical Infrastructure for Higher-Efficacy Drugs

Weight loss approaching 30% requires more support around each patient. Blood pressure and diabetes medications may need to be reduced as weight comes off, sometimes quickly. In TRIUMPH-3, the highest dose produced an average systolic blood pressure reduction of 9.3 mmHg (Eli Lilly and Company, 2026b).

Preserving muscle also becomes a greater concern with substantial weight loss. Nutrition counseling and resistance-training support should therefore be part of care planning. A 15-minute primary care visit every three months leaves little room to manage all these needs.

One practical option is to integrate obesity treatment into the chronic care management programs that many health systems already use for diabetes and hypertension. These programs have care coordinators, remote monitoring connections, and billing structures that can support monthly check-ins. They also track many of the conditions that may improve with weight loss.

Bariatric surgery teams should help design these pathways. A drug that produces weight loss in a range associated with surgery could change referral patterns and expand the use of medication before or after a procedure. Planning those connections now gives teams time to establish clear roles before demand increases.

Why the Preclinical Pipeline Deserves Attention

Retatrutide is the first triple agonist close to market, but other compounds are likely to follow. Academic and contract laboratories are studying how activity at different receptors affects weight loss, muscle preservation, and side effects such as dysesthesia.

That research requires reliable reference materials. Labs conducting receptor-binding assays or diet-induced obesity studies source research-grade retatrutide with batch-matched COAs to check identity and purity before adding results to a dataset. These findings may help shape the dosing and safety questions health systems ask about future compounds. The pipeline also has implications for patient care. Lilly states that retatrutide is investigational and legally available only to participants in its clinical trials. Public interest, however, has grown well ahead of approval (Eli Lilly and Company, 2026a).

Preparing for the Next Phase of Obesity Care

Triple-agonist research gives health systems a reason to revisit how they budget for and deliver obesity care. Decisions about coverage, dosing, follow-up, and staffing will shape how effectively future treatments fit into everyday practice. Planning should leave room for questions that remain unresolved, including pricing, long-term outcomes, and the support patients will need to stay on treatment.

Health systems can begin by reviewing gaps in their current programs, estimating the full cost of ongoing care, and bringing pharmacy, primary care, nutrition, and bariatric teams into the same planning process. Building that capacity now can help teams evaluate new therapies as evidence develops and offer patients a clearer path through treatment if approval follows.