Your GLP-1 side effect management strategy: Prevent muscle loss and MSK costs

GLP-1 medications have transformed the landscape of obesity care. For benefits leaders and health plans, they offer a rare promise: a clinically proven intervention that can deliver meaningful weight loss across at-risk populations. But that weight loss can come with a hidden risk. It often does not show up in pharmacy claims first. It shows up later through reduced strength, functional decline, falls, and musculoskeletal utilization. Research suggests that up to 39% of weight lost during GLP-1 use may come from lean mass.¹

Muscle is essential for metabolism, movement, and protection against injury. When lean mass declines during GLP-1 use, research suggests the risks around weakness, falls, disability, and downstream utilization can rise over time.² ³ ⁴ This kind of secondary exposure can make the long-term value of healthcare spend on GLP-1 harder to defend.

What are the side effects of GLP-1s?

GLP-1 receptor agonists, including semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound), are commonly prescribed for weight loss. The most well-known side effects include:

• Nausea, vomiting, diarrhea, and constipation¹² ¹³
• Appetite suppression that can contribute to lower food intake¹² ¹³
• Headaches, fatigue, and dizziness¹² ¹³
• Gallbladder issues and pancreatitis, in rare cases¹² ¹³
• Injection site reactions¹³

These effects often show up early in treatment and may fade over time. But that one dangerous side effect grows more severe the longer it goes unaddressed: loss of lean muscle mass.

How soon do GLP-1 side effects start?

Muscle loss is unique among GLP-1 side effects because it builds slowly and silently. Unlike gastrointestinal symptoms that may appear early and then ease, lean-mass loss can build gradually over weeks and months without obvious warning signs.¹

As lean mass declines, people may notice lower strength, lower functional reserve, and higher fall risk over time.³ This process all tends to happen without a diagnostic code or a pharmacy alert. By the time pain or instability prompts a claim, the damage is already done.

• Gastrointestinal issues can appear within hours or days
• Appetite suppression can lead to fatigue within weeks
• Muscle loss builds silently, especially in sedentary members

Muscle loss does not trigger a pharmacy flag or diagnostic code, so it often goes unnoticed. But its impact shows up later in the form of back pain, falls, joint instability, or disability claims. These events can lead to costly MSK care or surgical intervention.

Muscle loss is the GLP-1 side effect you can’t afford to ignore

GLP-1 use without structured support can leave members more exposed to lean-mass loss and the downstream risks that follow. This often does not appear clearly in pharmacy data, but it can show up later through musculoskeletal utilization, falls, weakness, and functional decline.

To manage GLP-1 side effects effectively, health plans and employers need a strategy to preserve lean muscle mass. Structured support that includes movement, nutrition guidance, and habit reinforcement can help reduce that risk and support more sustainable outcomes.

Benefits of lean muscle mass

• Helps protect joints and stabilize movement
• Supports balance and coordination
• Helps lower fall and injury risk
• Supports resting metabolism
• Helps preserve everyday function

Without strength-building movement, GLP-1 users risk losing a significant proportion of their lean muscle mass, which can accelerate decline in function and drive musculoskeletal claims₁. To manage GLP-1 side effects effectively, health plans and employers need a clear strategy to preserve lean muscle mass. 

Offering structured support alongside GLP-1 prescriptions is one scalable way to reduce risk and improve the odds of more sustainable outcomes.

Lean muscle retention is the best defense against MSK risk

During GLP-1-related weight loss, research suggests that up to 39% of weight lost may come from lean mass, particularly when members begin from a low-activity baseline.¹

During GLP-1-induced weight loss, Up to 39% of lean body mass is lost during GLP-1 usage, especially in inactive users₁. Losing this tissue slows metabolism, which means fat returns more quickly if the member discontinues the medication₁. That muscle isn’t easy to regain and the results are dangerous for patients and insurers alike:

• Lower lean mass can contribute to lower metabolic reserve and higher weight-regain risk
• Lower strength and balance can raise fall and injury risk
• Functional decline can increase disability exposure over time² ³ ⁴

This isn’t hypothetical. Sarcopenia (progressive loss of muscle tissue) doesn’t often show up as a line item on a claim. But its consequences do. These effects are well-documented in clinical literature:

• up to 33% of chronic pain cases in older adults²
• a 60% higher risk of falls³
• a 2.5x higher disability risk in people with sarcopenic obesity⁴

GLP-1s accelerate sarcopenia without a plan to prevent muscle loss, employers are setting themselves up for a second wave of downstream claims and costs. Sarcopenia adds nearly $900 in excess healthcare costs per member per year⁶.

When lean muscle is lost during GLP-1 therapy, the consequences don’t end with strength and mobility decline. The broader financial exposure includes chronic pain, increased ER visits, and even surgical intervention⁶. This is where the risk becomes most acute: among members who were already inactive or physically limited before treatment began.

Inactive members face the greatest risk

This low baseline is important context for understanding risk across the broader GLP-1 eligible population. The average GLP-1 user is not starting from a place of metabolic or physical resilience.

Sword Pulse, the cardiometabolic pillar of the AI Care Platform, is designed to support people managing blood pressure, blood sugar, cholesterol, weight, and GLP-1 use through continuous lifestyle support. The Pulse member population reflects how widespread this risk profile is:

• 76% of Pulse members are overweight or obese⁶
• 57% have an addressable health condition such as diabetes, high cholesterol, or a similar condition⁷
• 46% had low physical activity at baseline⁸

This population is particularly vulnerable to muscle loss when using GLP-1s. However, while muscle loss is a dangerous side effect of GLP-1s, it’s also one of the most preventable.

The solution is straightforward.

Structured support should be built into GLP-1 care strategies to help members preserve muscle, build sustainable habits, and reduce the risk that lean-mass loss undermines long-term results.

How to manage the GLP-1 side effect of potential muscle loss

Movement is an important part of managing the long-term risks that can accompany GLP-1 use. GLP-1s suppress appetite, but they don’t help patients retain muscle when weight is lost. Movement isn’t just a helpful adjunct to medication. For GLP-1 users, physical activity is a protection mechanism. Structured movement programs help to:

• Preserve lean mass and support metabolism
• Reduce fall and injury risk by improving strength and stability
• Build habits that make outcomes more sustainable if medication changes

Healthcare providers can proactively embed movement into a GLP-1 weight loss care model to prevent the dangerous side effect of lean muscle loss before it becomes a downstream cost driver.

How Pulse supports more sustainable GLP-1 outcomes

Pulse, the cardiometabolic pillar of the AI Care Platform, is built to support people using GLP-1 medications with continuous lifestyle support. For GLP-1 users, Pulse addresses the gaps medication alone does not cover: muscle preservation, strength-building support, nutrition guidance, and sustainable habits.

What does Pulse provide for GLP-1 users?

• Personalized support across movement, nutrition, and daily habits
• Ongoing engagement from Phoenix, Sword Health’s AI Care Specialist
• Guidance from a matched Health Specialist when nuance or clinical judgment matters
• Connected-device support, including smart scales, blood pressure monitors, and wearables where appropriate

This kind of continuous support helps members build strength, preserve lean mass, and stay engaged over time, while giving employers more visibility into whether GLP-1 strategies are producing sustainable value.

GLP-1 preauthorization of movement plans: drive sustainable weight loss

Some employers and care teams are exploring whether structured support should begin before or alongside GLP-1 treatment, especially for members starting from a low-activity baseline. That approach can:

• Improve readiness for change
• Build early strength and activity habits
• Create a stronger foundation for long-term outcomes

Within Pulse, 35% of members are currently using, have used, or are considering a GLP-1 medication¹³.

Pulse is designed to strengthen your GLP-1 strategy

Pulse provides GLP-1 wraparound care built around strength, nutrition guidance, connected data, and daily habit support. It is designed to help members preserve muscle, maintain function, and build routines that make outcomes more sustainable over time.

Employers and health plans can strengthen the long-term value of GLP-1 coverage by building structured support around the members most likely to need it.