GLP-1s for executives: weight loss, performance and the muscle loss question

GLP-1 drugs such as semaglutide (Wegovy, Ozempic) and tirzepatide (Zepbound, Mounjaro) produce large weight loss, and some of that loss is lean mass, not just fat. In a body composition analysis of semaglutide's STEP 1 trial, fat mass fell 19.3% and lean mass fell 9.7% over 68 weeks, although lean mass rose as a share of body weight. For executives, the real questions are whether you meet an FDA-approved indication, how to protect strength while losing weight, and why compounded versions carry risks the approved drugs do not.

You have probably noticed the shift already. A board member who looks ten years younger. A portfolio CEO who stopped drinking at dinners. A cofounder who quietly mentions a telehealth prescription. GLP-1s have moved from diabetes clinics into executive culture fast. The evidence on them is strong in some places and thin in others, and the muscle question sits right on that line.

This is an educational overview, not medical advice. Nothing here covers dosing or how to obtain these drugs. Any decision to start, stop or change a GLP-1 belongs in a conversation with your physician.

What are GLP-1 drugs, and what are they approved for?

GLP-1 receptor agonists mimic a gut hormone involved in appetite, digestion and blood sugar regulation. Tirzepatide also acts on a second hormone receptor, GIP. In practice, people on these drugs feel full sooner, think about food less, and eat less.

The FDA-approved uses have expanded well beyond diabetes:

• Chronic weight management. When the FDA approved Zepbound in November 2023, it was for adults with obesity (a BMI of 30 or higher) or overweight (a BMI of 27 or higher) with at least one weight-related condition, used with "a reduced calorie diet and increased physical activity." In the larger trial, people without diabetes on the highest dose lost on average 18% of their body weight compared with placebo.
• Cardiovascular risk reduction. In March 2024 the FDA approved Wegovy to reduce the risk of cardiovascular death, heart attack and stroke in adults with cardiovascular disease and either obesity or overweight.
• Obstructive sleep apnea. In December 2024 the FDA approved Zepbound for moderate to severe obstructive sleep apnea in adults with obesity, based on two trials in 469 adults without type 2 diabetes.

Note what is not on the list: "performance," "focus," or "getting lean for a summit keynote." Those are off-label motivations, and the risk-benefit math looks very different for a person without obesity or a weight-related condition.

What does the heart data show?

For executives with existing cardiovascular disease, this is the most important result. The trial behind Wegovy's cardiovascular approval enrolled more than 17,600 people. According to the FDA, major adverse cardiovascular events (cardiovascular death, heart attack or stroke) occurred in 6.5% of people on Wegovy and 8% on placebo.

That is a 1.5 percentage point absolute reduction in a high-risk population. It is meaningful, and it applies to people who already have cardiovascular disease plus obesity or overweight. It does not tell you what happens to a fit 42-year-old who wants to drop ten pounds.

Do GLP-1s cause muscle loss?

Yes, they cause lean mass loss, and so does nearly every form of substantial weight loss. The more useful question is how much, relative to fat, and what it means for strength and function.

The best-known data comes from a body composition substudy of STEP 1, the large semaglutide trial. A group of 140 participants had DXA scans, which estimate fat and lean tissue. The results, presented at the Endocrine Society's ENDO 2021 meeting by John Wilding and colleagues, covered 68 weeks of treatment.

There are two ways to read this, and both are true.

The reassuring read. Fat fell about twice as fast as lean mass in percentage terms, and visceral fat, the metabolically harmful fat around the organs, fell fastest. Because fat dropped more than lean tissue, the proportion of lean mass relative to total body mass actually rose by 3.0 percentage points. Body composition improved.

The cautious read. A 9.7% drop in lean body mass is not trivial. For someone who is already losing muscle with age, sitting through 12-hour days and skipping the gym during a fundraise, that is a loss worth taking seriously. Strength and muscle are strongly tied to how well people age.

What "lean mass" does and doesn't mean

DXA lean mass is not the same as muscle. It includes water, organs and other non-fat tissue. Some lean mass loss during weight loss reflects a smaller body needing less supporting tissue. So the STEP 1 number is an upper bound on muscle loss rather than a direct measurement of it.

It also does not tell you about function. The question an executive actually cares about is whether they will be weaker, slower to recover, or more fragile at 70. Body composition alone cannot answer that, which is why strength measures matter.

Why compounded and gray-market GLP-1s are a different risk

The approved drugs have large trials, known manufacturing standards and labeled warnings. Compounded versions do not have the same foundation, and the FDA has been unusually direct about it.

On its page on unapproved GLP-1 drugs, last updated September 1, 2026, the agency states: "compounded drugs are not FDA approved. This means the agency does not review compounded drugs for safety, effectiveness or quality before they are marketed."

The same page reports that as of May 31, 2026, the FDA had received 990 adverse event reports associated with compounded semaglutide and more than 730 associated with compounded tirzepatide. The agency notes these numbers are likely undercounts, because some state-licensed pharmacies are not required to report adverse events.

The specific problems the FDA flags:

• Dosing errors. Reports of adverse events, some requiring hospitalization, linked to mistakes in measuring and self-administering compounded injections, and to doses beyond those in FDA-approved labels.
• Different salt forms. Some compounders use semaglutide sodium or semaglutide acetate. The FDA says it "does not have information on whether these salts have the same chemical and pharmacologic properties as the active ingredient in the approved drug."
• Counterfeits. The FDA is aware of counterfeit Ozempic in the US supply chain, which could contain the wrong ingredients, wrong amounts or harmful substances.

For a founder, the pattern is familiar: the cheaper, faster, less regulated option looks efficient until something goes wrong. With a drug you inject weekly, the downside is not a missed deadline.

What the evidence says, and what it doesn't

Strong: GLP-1 drugs produce substantial weight loss in large randomized trials. Semaglutide reduced major cardiovascular events in adults with cardiovascular disease and obesity or overweight. Tirzepatide is approved for obstructive sleep apnea in adults with obesity.

Moderate: Lean mass falls along with fat during treatment, while body composition improves in proportion. The best-known data comes from a DXA substudy of 140 people, and DXA lean mass is not a direct measure of muscle.

Weak or missing: Evidence on cognitive or professional "performance" benefits in people without obesity. Long-term data on strength and function in people who use these drugs for years, especially without resistance training. Safety and quality data for compounded and gray-market products.

Known risks from FDA labeling: The approved products carry warnings that include thyroid C-cell tumors in rodents (with a boxed warning for Wegovy), pancreatitis, gallbladder problems and, for Wegovy, acute kidney injury, increased heart rate and suicidal behavior or thinking. Common side effects include nausea, diarrhea, vomiting and constipation.

If you are considering a GLP-1, the first step is a physician visit: whether you meet an approved indication, what your cardiovascular and metabolic risk actually is, and how your other medications interact.

Questions worth bringing to that appointment

Executives tend to walk into medical appointments underprepared and short on time. A short list helps:

• Do I meet an FDA-approved indication, or would this be off-label?
• Which of the labeled warnings apply to me, given my personal and family history?
• How will we track body composition and strength, not just weight?
• What happens to my plan if I travel constantly, skip meals on long days, or have a heavy drinking week?
• What is the plan if I decide to stop?

A good physician will welcome these questions. If a prescriber, telehealth platform or clinic cannot answer them, treat that as information about the quality of the care, not as a hurdle to get around.

What an executive can do this week

None of this requires a prescription, and all of it is useful whether or not you ever take a GLP-1.

Get a baseline. Ask your physician about labs, blood pressure and, if appropriate, a body composition scan. Record a simple strength marker you can repeat: a grip test, a set of push-ups, or a lift you already do.

Train for strength twice a week at minimum. Resistance training is the most reliable way to protect muscle during any weight loss. It does not need to be elaborate. It needs to be on the calendar like a board meeting.

Eat enough protein. Appetite suppression makes this harder, which is exactly why it matters. A registered dietitian or your physician can set a target for your body and health.

Judge progress by function, not the scale. Are you stronger, sleeping better, less winded on stairs? Those are the outcomes that matter at 60 and 80.

Look at the drivers. Many executives gain weight through stress, short sleep and alcohol used as an off switch. A drug can change appetite. It does not change a nervous system that has been in threat mode since the Series A. Our piece on what chronic stress does to a founder's body covers that mechanism, and meditation for sleep for executives addresses the sleep side.

The part a prescription doesn't cover

GLP-1s can change what you want to eat. They do not change why you reach for the second drink at 10 p.m., why you cannot sleep the night before a board meeting, or why rest feels like falling behind. Those patterns tend to come back when the medication stops or the next crisis arrives.

That is the layer we work on at Cinder: private 1:1 meditation coaching that trains stress regulation as a skill, so the habits that drove the weight gain in the first place have something better to replace them.

Apply for private coaching

Sources

• FDA's concerns with unapproved GLP-1 drugs used for weight loss, U.S. Food and Drug Administration, 2026
• FDA approves new medication for chronic weight management, U.S. Food and Drug Administration, 2023
• FDA approves first treatment to reduce risk of serious heart problems specifically in adults with obesity or overweight, U.S. Food and Drug Administration, 2024
• FDA approves first medication for obstructive sleep apnea, U.S. Food and Drug Administration, 2024
• Impact of semaglutide on body composition in adults with overweight or obesity: exploratory analysis of the STEP 1 study, Endocrine Society ENDO 2021 abstract (via Newswise), 2021