Everything the leaflet
doesn't have room for.
A plain-language reference for people on GLP-1 treatment. No forums, no before-and-afters, no supplements to sell — just what the evidence says, written so you can use it on a Tuesday morning.
Start here
How GLP-1 medicines actually work
Not appetite suppressants, not fat burners. They are copies of a gut hormone your body already makes — which explains almost everything.
Read the explainerMedicines
Eight products, four molecules — each with its own ladder and rules.
OzempicSemaglutideOnce weeklyWegovySemaglutideOnce weeklyRybelsusSemaglutideOnce dailyMounjaroTirzepatideOnce weeklyZepboundTirzepatideOnce weeklySaxendaLiraglutideOnce dailyVictozaLiraglutideOnce dailyTrulicityDulaglutideOnce weekly
Comparing two? Ozempic vs Wegovy · Mounjaro vs Zepbound · Ozempic vs Mounjaro · Wegovy vs Zepbound · Saxenda vs Wegovy · all comparisons
Basics
How the medicines work, and what to expect.
How long GLP-1 medicines stay in your systemHalf-lives, steady state, and the arithmetic behind a missed dose — including why stopping does not mean the effect ends that week.What to expect, month by monthA realistic timeline of the first year — what usually happens when, and which of it means something.
Dosing
Titration schedules, missed doses, and timing.
Dose schedules, drug by drugEvery GLP-1 medicine climbs a ladder of doses on a fixed timetable. Here is every schedule in one place, and the reasoning behind the pace.You missed a dose. Now what?The rules differ by product, and they hinge on how many days have passed. Here is the decision for each medicine, in the order you actually need it.
Side effects
What shows up, when it peaks, and what helps.
Side effects, week by weekNausea on a GLP-1 is not random. It follows the dose ladder on a schedule you can predict — and predicting it is most of what makes it manageable.Injection sites, and why rotation mattersThree approved areas, one simple rule, and a failure mode that quietly reduces how much drug you absorb.Constipation, and what actually helpsThe side effect most likely to persist rather than fade — and the one most responsive to three unglamorous changes.
Food & drink
Eating on a slower stomach, and what makes it worse.
What to eat on a GLP-1Your stomach empties slowly and your appetite has shrunk. The problem is no longer eating less — it is getting enough of what matters in.Alcohol on a GLP-1Not forbidden, but genuinely changed. Lower tolerance, a harsher next day, and — for many people — a drop in the desire to drink at all.Hydration, and why thirst stops workingThirst is an appetite signal, and these medicines quieten appetite signals. Mild dehydration is the most under-recognised problem on this treatment.
Body & results
Muscle, protein, and what the scale is telling you.
Protein, and the muscle you don't want to loseRapid weight loss takes lean tissue with it unless you make it not. This is the least discussed and most consequential part of GLP-1 treatment.When the scale stops movingMost stalls are not plateaus. Distinguishing the two comes down to where you are on the dose ladder and how long the flat stretch has lasted.Stopping, and what happens nextAppetite returns along a curve rather than switching back on. What the trials show about regain, and what actually changes the outcome.Exercise while you are losing weightNot for the calories. Resistance training is what tells your body to keep the muscle it would otherwise break down.Hair shedding on a GLP-1Common, alarming, and usually not the drug. What telogen effluvium is, why rapid weight loss triggers it, and what actually helps.Loose skin and facial changes"Ozempic face" is not a drug effect. It is what substantial weight loss looks like in a face — and knowing that changes what you can do about it.
Safety
Who should not take these, and what needs a clinician today.
Who should not take a GLP-1The absolute exclusions, the conditions that require caution, and the medicines that need rethinking before you start.Pancreatitis: what to watch forRare, serious, and easy to dismiss when nausea and abdominal discomfort have become normal. How to tell the difference.Drug interactions on a GLP-1A slower stomach changes how every oral medicine is absorbed. For most that is irrelevant — for a handful it is not, and those are worth knowing by name.Surgery, endoscopy and anaesthesiaA stomach that empties slowly may still hold food after a standard fast. This is the interaction people forget, and the one with the sharpest consequences.Pregnancy, contraception and fertilityWeight-management GLP-1s are not for use in pregnancy — and a slower stomach can affect the pill. Two facts that together catch people out.Low blood sugar on a GLP-1Uncommon on these medicines alone, and genuinely likely in combination with insulin or a sulfonylurea. Knowing which situation you are in matters.
Everyday life
Travel, supply, cost, and the parts nobody warns you about.
Shortages, supply and running outThis class has been intermittently unavailable since it became popular. What to do when your pharmacy cannot fill the prescription.Compounded and unofficial GLP-1sCheaper, easier to obtain, and not the same product. What compounding actually is, where the real risks sit, and what regulators have found.