NuSH Therapies (Nutrient-Stimulated Hormone Therapies)
Definition
Nutrient-stimulated hormone (NuSH) therapies is the term introduced in the 2025 ACC Concise Clinical Guidance to describe the third-generation class of obesity medications that act on metabolic pathways while controlling appetite. Current FDA-approved NuSH targets include glucagon-like peptide-1 (GLP-1) receptor agonists (liraglutide, semaglutide) and the dual GLP-1/GIP (glucose-dependent insulinotropic polypeptide) receptor agonist tirzepatide. Novel agents targeting additional NuSH pathways (glucagon, amylin) and multi-agonist combinations are in development.
Key Concepts
Why NuSH Therapies Are Central to Obesity Management
- Fill the treatment gap between insufficient lifestyle therapy and invasive bariatric surgery (sources/weight-mx-acc-2025, rating: very high)
- Target the disease mechanism of obesity — dysregulated hormonal pathways controlling appetite (hunger, satiety, satiation, cravings), not merely caloric restriction (sources/weight-mx-acc-2025, rating: very high)
- Titratable dosing allows minimizing side effects while maximizing weight loss, enabling individualized care (sources/weight-mx-acc-2025, rating: very high)
Eligibility
- BMI ≥30 kg/m² OR BMI ≥27 kg/m² with weight-related comorbidity (sources/weight-mx-acc-2025, rating: very high)
- Lifetime high BMI (not current BMI) may be used — consistent with chronic disease management framework (sources/weight-mx-acc-2025, rating: very high)
- Patients should NOT be required to "try and fail" lifestyle intervention before pharmacotherapy, per ACC 2025 CCG — a paradigm shift from prior guidelines (sources/weight-mx-acc-2025, rating: very high)
- Lifestyle interventions should always be offered alongside NuSH therapies (sources/weight-mx-acc-2025, rating: very high)
Approved Agents and Weight Loss Efficacy
| Agent | Mechanism | Max dose | Weight loss (trial) | Trial |
|---|---|---|---|---|
| Liraglutide (Saxenda) | GLP-1 RA | 3 mg SC daily | −8.0% | SCALE (56 wk) |
| Semaglutide (Wegovy) | GLP-1 RA | 2.4 mg SC weekly | −14.9% | STEP-1 (68 wk) |
| Tirzepatide (Zepbound) | Dual GLP-1/GIP RA | 15 mg SC weekly | −20.9% | SURMOUNT-1 (72 wk) |
(sources/weight-mx-acc-2025, rating: very high)
Weight Loss Thresholds for CV Outcomes
- ≥5%: improved triglycerides, fasting glucose, systolic BP; prevention of incident disease
- 10–15%: CVD risk reduction
-
15%: CV mortality reduction and HFpEF adverse outcome prevention (sources/weight-mx-acc-2025, rating: very high)
Cardiovascular Outcomes Evidence
- Liraglutide (LEADER, T2DM high CV risk): MACE HR 0.87 (95% CI 0.78–0.97)
- Semaglutide (SUSTAIN-6, T2DM high CV risk): MACE HR 0.74 (95% CI 0.58–0.95)
- Semaglutide (SELECT, CVD + BMI >27 + no T2DM, n=17,604, 3.3yr): MACE HR 0.80 (95% CI 0.72–0.90) — first MACE benefit in obesity + CVD without diabetes; HF hospitalization HR 0.79 NS
- Tirzepatide (SUMMIT, HFpEF + obesity, n=731, 104 wk): CV death/worsening HF HR 0.62 (95% CI 0.41–0.95) — first hard composite outcome benefit in obesity-HFpEF; KCCQ +6.9 pts (sources/weight-mx-acc-2025, rating: very high)
Safety Profile (Class)
- Primary adverse effects: GI (nausea, diarrhea, vomiting, abdominal pain, constipation) — dose-related; mitigated by slow titration
- Clinical trial discontinuation due to AEs: 4.3–7.1% across agents
- Contraindications (all NuSH therapies):
- Personal/family history of medullary thyroid carcinoma (MTC)
- Multiple endocrine neoplasia syndrome type 2 (MEN2)
- Hypersensitivity to product or excipients
- Cautions: pancreatitis, gallbladder disorders (increased risk on class — consider ursodiol in cholelithiasis), renal impairment, suicidal behavior
- Screening thyroid ultrasound NOT required before initiation (sources/weight-mx-acc-2025, rating: very high)
Practical Prescribing Points
- Semaglutide and tirzepatide preferred over liraglutide (highest efficacy and once-weekly dosing)
- Tirzepatide achieves marginally greater weight loss than semaglutide (consistent across RCTs and real-world data)
- Agent selection often driven by insurance coverage, availability, and cost (US annual cost: semaglutide ~$14,080; tirzepatide ~$8,126)
- If ≥3 missed doses of once-weekly agent: consider dose reduction on resumption
- Semaglutide and tirzepatide can be interchanged clinically
- Compounded NuSH therapies are strongly discouraged — risk of dosing errors, impurities, and counterfeit agents (sources/weight-mx-acc-2025, rating: very high)
- Long-term continuation is the default plan: weight regain is expected after discontinuation
Comorbidity Management During NuSH Therapy
- De-escalate antihypertensives as BP falls (avoid hypotension)
- De-escalate diuretics in HF as weight falls (avoid intravascular depletion)
- Reduce T2DM medications to avoid hypoglycemia
- Re-check TSH at 10% weight loss (levothyroxine may be weight-based)
- Adjust CPAP settings or repeat OSA assessment at ≥7% weight loss
- Surgery/anesthesia: may continue if no elevated aspiration risk; if held, 1 week before elective surgery considered (sources/weight-mx-acc-2025, rating: very high)
Contradictions / Open Questions
- "Try and fail" lifestyle paradigm overturned: ACC 2025 CCG explicitly states patients should not be required to fail lifestyle therapy before pharmacotherapy — this represents a departure from prior obesity guidelines (sources/weight-mx-acc-2025, rating: very high)
- Tirzepatide MACE data outside HFpEF lacking: SELECT established semaglutide MACE benefit in non-T2DM CVD patients. Whether tirzepatide confers equivalent MACE reduction is being tested in SURMOUNT-MMO (n=15,374; estimated completion 2027) (sources/weight-mx-acc-2025, rating: very high)
- SURPASS-CVOT (tirzepatide vs dulaglutide in T2DM + CVD): ongoing — tirzepatide CVOT primary endpoint data pending (sources/weight-mx-acc-2025, rating: very high)
- Duration of therapy and weight regain: Obesity is a chronic disease; no plateau seen in RCTs. Long-term data beyond 4 years are limited. Weight regain after discontinuation is the expected natural history (sources/weight-mx-acc-2025, rating: very high)
- Access and affordability: NuSH therapies cost ~$8,000–$15,000/year in the US; not covered by Medicare for obesity alone. Whether coverage gaps drive compounding risks and outcomes disparities is a systemic unresolved issue (sources/weight-mx-acc-2025, rating: very high)
Connections
- Related to entities/Semaglutide — GLP-1 RA; SELECT, STEP-HFpEF, SUSTAIN-6, SOUL
- Related to entities/Tirzepatide — dual GIP/GLP-1 RA; SUMMIT, SURMOUNT-1, SURMOUNT-MMO ongoing
- Related to concepts/GLP-1-Receptor-Agonists — broader drug class including dulaglutide, exenatide
- Related to entities/Obesity — primary indication; chronic disease framework
- Related to entities/HFpEF — obesity-HFpEF phenotype; STEP-HFpEF and SUMMIT data
- Related to entities/Heart-Failure — comorbidity de-escalation during weight loss
- Related to entities/MASLD — NuSH therapies improve MASH histology (ESSENCE, SYNERGY-NASH)