Home / GLP-1 medications
The medication hub
GLP-1 medications, without the sell.
What semaglutide and tirzepatide do, what the trial evidence actually shows, what they cost, who they are not for, and what the side effects are really like. We are not selling a prescription. We are trying to make your appointment a better one.
01
What GLP-1 medications actually do
GLP-1 is a hormone your gut already releases when you eat. It is part of how your body works out that food has arrived and that it can stop asking for more. Semaglutide and tirzepatide are drugs that imitate that signal and hold it there for far longer than the natural version lasts. Tirzepatide acts on a second gut hormone receptor (GIP) as well.
The practical effect is on appetite, not on fat. These medications slow how quickly the stomach empties and change how full you feel and for how long. Food stops arguing with you all afternoon. People eat less because they want less, not because they are gritting their teeth harder.
Which bar this moves
Before: appetite signal turned up
Hard to hold
On a GLP-1: the same signal, turned down
Energy out unchanged
Energy in: the side the drug acts on
Energy out: the drug does not raise this
This is the whole mechanism, in one picture. A GLP-1 turns the left bar down. It does not raise the right bar, it does not “burn fat”, and it does not repeal the arithmetic in What is a kJ?. Anyone describing these drugs as fat burners is either confused or selling something.
What it changes
The left bar. It turns the appetite signal down. For someone who has spent years arguing with that signal, that is not a small thing.
What it doesn’t
The equation, the right bar, the monthly cost, the side effects, or the fact that stopping the drug generally lets the signal come back.
02
What the evidence shows, and how to read it
There is one headline figure most people have heard, and it is worth stating precisely rather than loosely, because the loose version is what does the damage.
In STEP 1, a 68-week randomized trial of semaglutide 2.4 mg, participants lost a mean of about 15% of body weight, compared with about 2.5% in the placebo group. Both groups also received lifestyle support.
Read it yourself: Wilding et al., “Once-Weekly Semaglutide in Adults with Overweight or Obesity,” New England Journal of Medicine, 2021. The tirzepatide equivalent is SURMOUNT-1, Jastreboff et al., NEJM 2022. Prescribing information, including the boxed warning, is in the FDA labels for Wegovy (semaglutide) and Zepbound (tirzepatide).
~15%
Mean, semaglutide 2.4 mg
Average change in body weight across the treatment group over the trial period.
~2.5%
Mean, placebo
The comparison group in the same trial, with the same lifestyle support.
68
Weeks
The stated period. The figure describes that window and nothing beyond it.
How to read a group average
That 15% is an average, not a promise. Inside a mean, some people lost considerably more, some lost very little, and some stopped the drug before the trial ended. A trial population is screened, supported and monitored in ways ordinary life is not. The figure tells you what a drug did for a group over a stated period. It does not tell you what it will do for you, and no one who quotes it at you can know that either.
You will notice this hub quotes exactly one efficacy number. That is deliberate. The internet is saturated with percentages torn loose from the trial, the dose and the duration that produced them, and each retelling makes them sound a little more like a guarantee. We would rather give you one figure you can actually check than ten you cannot.
03
What they cost, month after month
Cost is the part most coverage skips, and it is the part that ends most courses of treatment. For most people these are ongoing prescriptions, not a course: the appetite signal generally returns when the drug stops, so the monthly figure is the one that matters, not the first month.
We do not publish a price here, and we will not. US pricing moves constantly, differs by plan, dose, pharmacy and manufacturer program, and a stale number on a website is worse than no number. What we can tell you is which questions determine your figure.
We do not track United States provider pricing and will not pretend to. If that is your market, NutritionNC paid for a year at eight US telehealth companies and published the totals.
| What decides your cost | What to find out |
|---|---|
| Insurance coverage | Whether your plan covers this drug for weight management at all. Many plans cover it for type 2 diabetes but not for weight. Ask for it in writing.Coverage for one indication tells you nothing about the other. |
| Prior authorization | Whether the plan requires documentation before it will pay, and what happens if it is refused. |
| Manufacturer self-pay | Whether a direct-from-manufacturer price exists for your dose, and what it is this month.These programs are repriced and restructured regularly. |
| Dose escalation | What the cost looks like at the maintenance dose, not the starting dose. |
| Duration | What twelve months of this costs you, and whether that is a number you can carry indefinitely. |
| Compounded versions | Whether what you are being offered is the FDA-approved product or a compounded preparation. They are not the same thing, and the difference is worth a direct question. |
Our position on this
We do not sell medication, we do not run a pharmacy, and there is nothing to buy on this page. If a site quotes you a suspiciously round monthly price next to a “start now” button, that price is marketing, and you should treat it as such.
04
Who they are for, and who they aren’t
Only a prescriber who knows your history can answer this for you. What follows is the shape of the conversation, so that you walk into it already knowing what will be asked.
A reasonable conversation to have if
- You have a weight-related health condition your clinician is already managing, and diet and activity changes have not moved it.
- Appetite is the thing you keep losing to, rather than a lack of knowledge or effort.
- You understand this is likely to be ongoing, and the monthly cost is one you can sustain.
- You want a tool alongside the arithmetic, rather than instead of it.
Not the right tool if
- You are pregnant, planning pregnancy, or breastfeeding.
- You have a personal or family history of medullary thyroid carcinoma, or MEN 2. This is a labeled contraindication and a prescriber will ask.
- You have a history of pancreatitis, or an eating disorder, without that being fully on the table with your clinician.
- You are hoping for a short course that fixes something permanently. That is not what these drugs are.
Before your appointment
Bring your full medication list, including anything over the counter. Some prescriptions raise appetite or weight on their own, and if that is what is happening, changing them may be the more direct move. Our one published guide covers exactly this.
05
Side effects, stated plainly
Most side effects of these drugs are gastrointestinal, most are worst while the dose is being raised, and most ease over time. But “most” is doing real work in that sentence. Enough people find them intolerable that discontinuation is a normal outcome, not a personal failure.
| Category | What it looks like |
|---|---|
| Common, gut | Nausea, vomiting, diarrhea, constipation, reflux, burping, abdominal pain.Usually worst during dose escalation; often eases, sometimes doesn’t. |
| Common, general | Fatigue, headache, dizziness, injection-site reactions. |
| Why people stop | Persistent nausea and vomiting, most often. Cost is the other common reason, and it is not a lesser one. |
| Serious, uncommon | Pancreatitis, gallbladder disease, kidney injury from dehydration, and thyroid C-cell tumor findings that carry a boxed warning in the US labeling.Uncommon does not mean impossible. These are the ones to know the warning signs for. |
| Worth planning for | Losing weight quickly can mean losing muscle with it. Protein intake and resistance movement are the standard countermeasures. Raise them at the start rather than after. |
Stopping because a drug makes you feel unwell is a medical decision, not a character test.
06
The guides in this hub
This hub is new and mostly unwritten. Rather than pad it out, we are listing what exists and what doesn’t. A page marked in progress has not been written yet, and we would rather show you the gap than fill it with something thin.
Understanding Medication-Induced Weight Gain
When the prescription you already take is the thing moving the bar.
Published
How Many Calories Does Ozempic Cut?
The measured intake drop, with a real number and the study behind it.
Published
Knowing your own energy needs before and during treatment.
Published
Balancing and burning calories safely while appetite is down.
Published
Food Noise and GLP-1 Medications
What food noise is, and how the drugs quiet it.
Published
What semaglutide and tirzepatide do
The mechanism in full: GLP-1, GIP, gastric emptying, satiety.
In progress
What they cost, month after month
Coverage, prior authorization, self-pay, and the twelve-month question.
In progress
Side effects people actually stop over
What discontinuation really looks like, and how to plan around it.
In progress
Who they aren’t for
Contraindications, cautions, and the conversations that come first.
In progress
What to ask before your appointment
A printable list of questions, and what a straight answer sounds like.
In progress
What happens when you stop
Weight regain, appetite return, and what the evidence does and doesn’t say.
In progress
While you wait
The arithmetic underneath all of this is already written, and it does not expire.
What is a kJ? · The energy balance library · How we handle medical claims
Educational, not medical advice
One efficacy figure, sourced and framed
Unwritten pages marked as unwritten