35 GLP-1 Questions, Answered From the Trials and Labels | GLP-1 Help

Question 1

How do GLP-1 drugs actually work?

Accepted Answer

Semaglutide and tirzepatide copy gut hormones that tell the brain you have eaten. In feeding studies people ate about a third less at a buffet meal. Here is what is measured, what is inferred, and what is still mouse data. Full answer with sources: https://glponehelp.com/how-it-works

Question 2

What are the side effects, and how common are they?

Accepted Answer

Nausea 44% vs 16% on placebo with Wegovy; 25 to 29% vs 8% with Zepbound. Every common side effect from the four US labels, drug versus placebo, plus the serious warnings and how often people stopped. Full answer with sources: https://glponehelp.com/side-effects

Question 3

Why does it cause nausea, and how long does it last?

Accepted Answer

44 of 100 people on Wegovy reported nausea, versus 16 on placebo. Median episode: 8 days. Why it happens (slow stomach plus brainstem), when it peaks, what has actual evidence behind it, and the warning signs the labels list. Full answer with sources: https://glponehelp.com/nausea

Question 4

Why does it cause constipation, and what helps?

Accepted Answer

Constipation affected 24% on Wegovy vs 11% on placebo, and a typical episode lasted 47 days, far longer than nausea. What the labels and reviews say, what has never been tested, and when it becomes urgent. Full answer with sources: https://glponehelp.com/constipation

Question 5

Why does it cause diarrhea?

Accepted Answer

Diarrhea affected 30% on Wegovy vs 16% on placebo and 19 to 23% on Zepbound vs 8%. The median episode lasted 3 days. The labels' concern is dehydration and kidney injury. The facts, from the labels and trials. Full answer with sources: https://glponehelp.com/diarrhea

Question 6

Why do I feel so tired?

Accepted Answer

Fatigue was reported by 11% on Wegovy vs 5% on placebo, and 5 to 7% on Zepbound vs 3%. No trial has studied why. The likely contributors, labelled honestly as likely, and the signs that it is something else. Full answer with sources: https://glponehelp.com/fatigue

Question 7

Does it cause hair loss?

Accepted Answer

Hair loss was reported by 3% on Wegovy 2.4 mg vs 1% on placebo, 6% on 7.2 mg, and 7.1% of women on Zepbound. The labels link it to weight reduction. What telogen effluvium is and how it usually behaves. Full answer with sources: https://glponehelp.com/hair-loss

Question 8

What happens when you stop taking it?

Accepted Answer

Four randomized trials followed people after semaglutide or tirzepatide stopped. On average about two-thirds of the lost weight came back within a year, but the spread is wide. What the trials show, what they do not, and what is known about maintenance. Full answer with sources: https://glponehelp.com/stopping

Question 9

How long does it take to work?

Accepted Answer

Dose build-up takes 16 to 20 weeks. In STEP 4 people lost 10.6% in the first 20 weeks on semaglutide; in SURMOUNT-4, 20.9% in 36 weeks on tirzepatide. What the first weeks, months and year looked like in the trials. Full answer with sources: https://glponehelp.com/how-long-to-work

Question 10

Why am I not losing weight, or why did it stop?

Accepted Answer

About 1 in 6 people on Wegovy and 1 in 10 on Zepbound lost under 5% in the trials, and everyone's curve flattened eventually. What a plateau is, what the trials tested, and what to discuss with your prescriber. Full answer with sources: https://glponehelp.com/not-losing-weight

Question 11

How long do the side effects last?

Accepted Answer

In the semaglutide trials the median nausea episode lasted 8 days, vomiting 2, diarrhea 3 and constipation 47. Most started during the dose build-up and peaked around week 20. The timeline, from the trials. Full answer with sources: https://glponehelp.com/how-long-side-effects-last

Question 12

What should I eat, and how much protein?

Accepted Answer

People on GLP-1 drugs ate about a third less in feeding studies. Protein targets of 1.2 to 1.6 g/kg are expert consensus, not trial results. What is measured, what is advice, and what nobody has tested. Full answer with sources: https://glponehelp.com/what-to-eat

Question 13

Can I drink alcohol on a GLP-1?

Accepted Answer

Neither label lists an alcohol interaction. Alcohol can worsen nausea and adds to low-blood-sugar risk with some diabetes medicines. A small 2025 trial found semaglutide reduced how much people drank. The facts. Full answer with sources: https://glponehelp.com/alcohol

Question 14

Do I take it with food or on an empty stomach?

Accepted Answer

The weekly injections can be given at any time of day, with or without meals. The semaglutide tablets are different: empty stomach, a small sip of water, and a 30-minute wait. Straight from the labels. Full answer with sources: https://glponehelp.com/with-food

Question 15

Does it cause muscle loss, and what is "Ozempic face"?

Accepted Answer

The '40% muscle' claim comes from one 140-person DXA substudy and a term (lean mass) that is mostly water and organ, not muscle. Here is what STEP 1, SURMOUNT-1 and the MRI studies actually found. Full answer with sources: https://glponehelp.com/muscle-loss

Question 16

Can it cause depression, anxiety or suicidal thoughts?

Accepted Answer

In January 2026 the FDA asked for the suicidal behavior warning to be removed from Wegovy, Zepbound and Saxenda after reviewing 91 trials with 107,910 people. What the data show, what they cannot show, and when to call. Full answer with sources: https://glponehelp.com/depression-anxiety

Question 17

Can it cause headaches?

Accepted Answer

Headache was reported by 14% on Wegovy vs 10% on placebo. Zepbound's label does not list it among common reactions. Possible reasons such as dehydration and eating less have not been studied. The facts and the warning signs. Full answer with sources: https://glponehelp.com/headache

Question 18

Does it cause thyroid cancer? What is the boxed warning?

Accepted Answer

Every GLP-1 weight-loss label carries a boxed warning about thyroid C-cell tumours in rodents. A Scandinavian study of 145,410 users found no substantial increase in humans over about 4 years. Who should not take them, and the symptoms to report. Full answer with sources: https://glponehelp.com/thyroid-cancer

Question 19

Can it affect my eyes or vision (NAION)?

Accepted Answer

Europe's regulator classed NAION, a sudden optic-nerve stroke, as a very rare side effect of semaglutide: up to 1 in 10,000. The first study suggested a 4 to 7 times higher risk; larger studies found about 2 to 3 times. What it means and what to do. Full answer with sources: https://glponehelp.com/vision-naion

Question 20

What about pregnancy, birth control and breastfeeding?

Accepted Answer

Wegovy's label says to stop at least 2 months before a planned pregnancy. Zepbound's says to stop when pregnancy is recognized, and to use non-oral or backup contraception for 4 weeks after starting and each dose increase. The label text, compared. Full answer with sources: https://glponehelp.com/pregnancy

Question 21

How long does it stay in my system?

Accepted Answer

Semaglutide has a half-life of about 1 week and stays in the blood for about 5 to 7 weeks after the last dose. Tirzepatide's half-life is about 5 days. What that means for side effects, appetite and planning. Full answer with sources: https://glponehelp.com/how-long-in-system

Question 22

Do I need to stop it before surgery or a procedure?

Accepted Answer

Both labels warn that food can stay in the stomach during anaesthesia. 2024 multisociety guidance says most people may continue, with a 24-hour liquid diet for higher-risk patients. What the labels and guidance say. Tell your surgical team. Full answer with sources: https://glponehelp.com/surgery

Question 23

Ozempic, Wegovy, Mounjaro, Zepbound: what is the difference?

Accepted Answer

Ozempic and Wegovy are both semaglutide; Mounjaro and Zepbound are both tirzepatide. The only head-to-head trial found 20.2% vs 13.7% weight loss at 72 weeks. What differs is the approved use, the doses and the side-effect profile. Full answer with sources: https://glponehelp.com/ozempic-vs-wegovy-vs-zepbound

Question 24

Are the pills as effective as the injections?

Accepted Answer

The 25 mg Wegovy tablet produced 13.6% weight loss at 64 weeks versus 2.2% on placebo. The injection's trial found 14.9% at 68 weeks. Different trials, similar range, strict empty-stomach rule. What is known so far. Full answer with sources: https://glponehelp.com/pills-vs-injections

Question 25

Does it need to be refrigerated? What if it got warm?

Accepted Answer

Wegovy single-dose pens: up to 28 days at 8 to 30 C before use. Zepbound and Mounjaro: up to 21 days at up to 30 C. Ozempic: 56 days after first use. The exact storage rules from the four labels, plus what the labels say about freezing. Full answer with sources: https://glponehelp.com/refrigeration

Question 26

What are "sulfur burps", and are they a real side effect?

Accepted Answer

Burping (eructation) was reported by 7% on Wegovy vs under 1% on placebo, and 4 to 5% on Zepbound vs 1%. The rotten-egg smell has not been studied. What is measured, what is guesswork, and when burping is a warning sign. Full answer with sources: https://glponehelp.com/sulfur-burps

Question 27

Why do I have heartburn or reflux?

Accepted Answer

Indigestion was reported by 9% on Wegovy vs 3% on placebo and reflux (GERD) 5% vs 3%. Zepbound: indigestion 9 to 10% vs 4%, reflux 4 to 5% vs 2%. What the labels show and when chest symptoms need urgent care. Full answer with sources: https://glponehelp.com/heartburn

Question 28

Why do I feel dizzy or light-headed?

Accepted Answer

Dizziness was reported by 8% on Wegovy vs 4% on placebo; low-blood-pressure events 1.3% vs 0.4%, more often in people on blood pressure medicines. Zepbound: hypotension 1.6% vs 0.1%. The numbers and warning signs. Full answer with sources: https://glponehelp.com/dizziness

Question 29

Is a red, itchy or bruised injection site normal?

Accepted Answer

Injection-site reactions were reported by 1.4% on Wegovy vs 1% on placebo, and 6 to 8% on Zepbound vs 2%: redness, itching, bruising, pain, rash. The label numbers, site rotation, and signs of a serious allergic reaction. Full answer with sources: https://glponehelp.com/injection-site

Question 30

What is "food noise", and why does it go quiet?

Accepted Answer

"Food noise" is not a medical term, but the trials measured something close: fewer and weaker cravings, and less desire for sweet and savoury food on semaglutide. What was measured in people, and what is still mouse research. Full answer with sources: https://glponehelp.com/food-noise

Question 31

Why do I feel cold all the time?

Accepted Answer

Feeling cold is not listed in the Wegovy or Zepbound labels and no trial has studied it. Possible explanations are eating much less and losing body fat. What is known, what is not, and when cold intolerance needs a check. Full answer with sources: https://glponehelp.com/feeling-cold

Question 32

Can it change my period?

Accepted Answer

Menstrual changes are not listed in the Wegovy or Zepbound labels and have not been studied directly. Weight loss itself can change cycles, and Zepbound can make birth control pills less reliable. What is known. Full answer with sources: https://glponehelp.com/period-changes

Question 33

Can it cause vivid dreams or change my sleep?

Accepted Answer

Vivid dreams are not in the labels and have not been studied. What is measured: Zepbound is approved for obstructive sleep apnea, cutting breathing pauses by about 25 to 29 an hour vs about 5 on placebo. Full answer with sources: https://glponehelp.com/vivid-dreams

Question 34

Will I have loose skin?

Accepted Answer

No GLP-1 trial has measured loose skin. People in the trials lost 15 to 21% of body weight on average, a range where some loose skin is common. What affects it, and why claims about prevention are untested. Full answer with sources: https://glponehelp.com/loose-skin

Question 35

Can I space out doses or stay on a lower dose for maintenance?

Accepted Answer

SURMOUNT-MAINTAIN found people kept 96.5% of their weight loss on full-dose tirzepatide, 67.9% on 5 mg, and 42.8% on placebo. Spacing out injections and tapering have no completed randomized trials. What is known; not advice. Full answer with sources: https://glponehelp.com/spacing-doses

35 GLP-1 questions, answered

Starting

Using

Stopping

Safety

From the forums