How GLP-1 Medications Work

Does GLP-1 affect oral birth control?

Tirzepatide (Mounjaro, Zepbound) has documented reduced absorption of oral contraceptives during the first 4 weeks of each dose increase. Us

Why do I have no appetite on Zepbound?

Tirzepatide activates two gut hormones (GIP + GLP-1) that signal fullness to the brain at supra-physiologic levels. It's not willpower; the

What happens if I miss a weekly GLP-1 dose?

If within 5 days: take the missed dose as soon as you remember, then resume the regular schedule. More than 5 days late: skip it and inject

Can I take a GLP-1 with metformin?

Yes — the combination is FDA-approved and commonly prescribed for type 2 diabetes. There is no metabolic interaction. The two share a GI sid

Can you take a GLP-1 with high blood pressure medication?

Yes. GLP-1 medications combine safely with all major antihypertensive classes (ACE inhibitors, ARBs, beta blockers, diuretics, calcium chann

Is Ozempic the same as Wegovy?

Same active molecule (semaglutide), different FDA indications and maximum doses. Ozempic = type 2 diabetes, max 2 mg/week. Wegovy = chronic

How do you inject a GLP-1 safely?

Rotate sites between abdomen (≥2 inches from navel), front of thigh, and back of upper arm. Inject at room temperature (cold pens sting). Pi

Is GLP-1 safe to take with thyroid medication?

Yes. GLP-1 medications do not interact with levothyroxine or other thyroid hormones. Take levothyroxine on its usual empty-stomach schedule

Can GLP-1 help with sleep apnea?

Yes. Zepbound (tirzepatide) became the first medication FDA-approved for moderate-to-severe obstructive sleep apnea in adults with obesity (

Does GLP-1 help with fatty liver (NAFLD/NASH)?

Yes. Multiple GLP-1 trials show liver-fat reduction and improvement in fibrosis markers. Tirzepatide (SYNERGY-NASH, NEJM 2024) achieved NASH

Does GLP-1 improve cholesterol?

Yes, modestly. GLP-1 medications reduce triglycerides 10-20%, LDL 5-10%, and ApoB ~7%. Most of the effect comes from weight loss, but a smal

Can GLP-1 help with binge eating disorder?

Promising preliminary evidence. Small RCTs and case series show GLP-1 reduces binge frequency and food-reward cravings in adults with BED. N

Does GLP-1 prevent heart attacks?

Yes for semaglutide — SELECT (NEJM 2023) showed a 20% reduction in major adverse cardiovascular events (MACE: heart attack, stroke, CV death

Does GLP-1 change taste or food preferences?

Yes, commonly. Patients frequently report aversions to previously-enjoyed foods (especially fried, very rich, or very sweet items), reduced

Can GLP-1 help with alcohol or opioid use disorder?

Promising preliminary signal for both. GLP-1 acts on brain reward circuits that overlap with addiction pathways. Several RCTs in alcohol use

STEP-1: Semaglutide Treatment Effect in People with Obesity — 1

−14.9% mean body-weight reduction on semaglutide vs −2.4% placebo (P<0.001)

SURMOUNT-1: A Study of Tirzepatide in Participants with Obesity or Overweight

−15.0% (5 mg), −19.5% (10 mg), −20.9% (15 mg) on tirzepatide vs −3.1% placebo

SUSTAIN-6: Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes

26% relative reduction in MACE on semaglutide vs placebo (HR 0.74, 95% CI 0.58-0.95; P=0.02 for non-inferiority and superiority)

SELECT: Semaglutide Effects on Heart Disease and Stroke in Patients with Overweight or Obesity

20% relative reduction in MACE on semaglutide 2.4 mg vs placebo (HR 0.80, 95% CI 0.72-0.90; P<0.001)

SURPASS-2: A Study of Tirzepatide versus Semaglutide in Participants with Type 2 Diabetes

Tirzepatide superior at all three doses: −2.01% (5 mg), −2.24% (10 mg), −2.30% (15 mg) vs −1.86% semaglutide 1 mg

FLOW: A Research Study to See How Semaglutide Works Compared to Placebo in People with Type 2 Diabetes and Chronic Kidney Disease

24% relative reduction in primary composite on semaglutide vs placebo (HR 0.76, 95% CI 0.66-0.88; P<0.001)

SURMOUNT-OSA: A Study of Tirzepatide in Adults with Obesity and Moderate-to-Severe Obstructive Sleep Apnea

−25 to −29 events/hour mean reduction on tirzepatide vs −5 events/hour placebo

SURMOUNT-4: Tirzepatide Maintenance — Continued versus Withdrawn

Continued tirzepatide: additional −5.5% weight loss. Withdrawn to placebo: regained 14% of body weight by week 88 (about 2/3 of weight previ