GLP-1s: The Ozempic Explainer

GLP-1 stands for "glucagon-like peptide-1." It's a hormone your body makes naturally.

When you eat, your gut releases GLP-1. This hormone does a few things:

• Tells your brain you're full — It signals satiety so you stop eating
• Slows your stomach — Food moves through slower, keeping you full longer
• Helps with blood sugar — It triggers insulin release when you need it

The problem? Natural GLP-1 only lasts a few minutes in your body before it's broken down. It works, but only briefly.

GLP-1 medications are synthetic versions that last much longer—days instead of minutes. This creates a sustained effect that natural GLP-1 can't achieve.

Semaglutide (Ozempic, Wegovy, Rybelsus)

• Ozempic: FDA-approved for type 2 diabetes
• Wegovy: Same molecule, higher dose, approved for weight loss
• Rybelsus: Oral version (pill instead of injection)

Tirzepatide (Mounjaro, Zepbound)

• The "next generation"—hits two receptors instead of one (GLP-1 + GIP)
• Mounjaro: Approved for diabetes
• Zepbound: Same molecule, approved for weight loss
• Generally more effective than semaglutide, but newer

Older options (Liraglutide/Saxenda)

• First-generation GLP-1s
• Daily injections (vs weekly for newer ones)
• Less effective but more long-term safety data

In a word: remarkably.

Semaglutide (Wegovy) results:

• Average weight loss: 15-17% of body weight
• About 1/3 of people lose more than 20%
• Results continue improving for about 60-68 weeks

Tirzepatide (Zepbound) results:

• Average weight loss: 20-25% of body weight
• About 1/3 of people lose more than 25%
• The strongest weight loss drug available

To put this in perspective: Before GLP-1s, medical weight loss interventions averaged 5-10% weight loss. These drugs roughly doubled or tripled that.

GLP-1s work, but they're not side-effect-free. Here's what to expect:

Very common (expect these):

• Nausea — Especially in the first weeks and after dose increases
• Constipation — Your gut is moving slower; things back up
• Reduced appetite — This is the point, but it can be intense

Common:

• Fatigue — Especially if you're not eating enough
• Headaches — Often from dehydration
• Diarrhea — Less common than constipation, but happens

Less common but important:

• Gallbladder issues — Rapid weight loss increases gallstone risk
• Pancreatitis — Rare but serious; severe abdominal pain = ER
• Muscle loss — If you don't eat protein and exercise

The "Ozempic face" phenomenon:
Rapid fat loss can make your face look gaunt. This isn't a drug side effect per se—it's just what happens when you lose a lot of weight quickly. It's more noticeable if you don't maintain muscle through protein and exercise.

Here's something not enough people talk about: When you lose weight, you lose both fat AND muscle. With GLP-1s, studies show about 25-40% of weight loss can be lean mass (muscle) if you're not careful.

Why does this matter?

• Muscle keeps your metabolism high
• Muscle is what makes you functional as you age
• Losing muscle makes it easier to regain weight later

The solution:

1. Eat enough protein (0.8-1g per pound of goal body weight)
2. Do resistance training (weights, bands, bodyweight)
3. Don't slash calories too aggressively

GLP-1s make you eat less automatically. Your job is to make sure what you DO eat is protein-rich, and that you're giving your muscles a reason to stick around.

This is the big question: Are GLP-1s a lifetime commitment?

The honest answer: For most people, probably yes.

Studies show that when people stop taking GLP-1s, they typically regain about 2/3 of the weight they lost within a year. This makes sense—you're removing the thing that was suppressing your appetite.

Some people are able to maintain at a lower dose. Some can transition off with very careful lifestyle changes. But most people who want to keep the results will stay on some form of the medication long-term.

This isn't necessarily bad—we don't expect people to stop blood pressure medications—but it's something to consider before starting.

Good candidates:

• BMI over 30 (or over 27 with weight-related health issues)
• People who've tried lifestyle changes without lasting success
• Those with type 2 diabetes or prediabetes
• People willing to commit to long-term treatment

Probably not right for:

• People wanting to lose "vanity pounds" (10-15lbs)
• Those with history of medullary thyroid cancer or MEN 2
• People with history of pancreatitis
• Those who can't commit to protein and exercise
• Anyone seeking a temporary fix

GLP-1s are powerful tools, but they work best as part of an overall approach—not as a standalone magic solution.