The consultation where someone starts one of these tends to be about eligibility and dose. It is rarely about the things that determine whether they are still taking it in a year.
Those things are mostly logistical, mostly cheap, and mostly get worked out the hard way in month three.
1. Confirm you actually qualify
BMI of 30 or above, or 27 or above with a weight-related condition. If you are in the 27 to 30 band and have never been assessed for sleep apnoea or prediabetes, that assessment may be the thing that makes you eligible. The full criteria are in do you qualify.
2. Rule out the contraindications
Short list, and one of them is absolute.
- Personal or family history of medullary thyroid carcinoma, or MEN2. If a relative had thyroid cancer, find out which type — see the thyroid warning.
- Pregnancy, planned pregnancy, or breastfeeding
- Previous pancreatitis warrants a proper conversation — see pancreatitis on a GLP-1
- Active eating disorder
3. Establish the money before the prescription
The single most common cause of an interrupted first year is not side effects. It is discovering in month four that the coverage was temporary.
Ask specifically: is this covered, under which diagnosis, for how long, and what happens at the next plan year. Then look at what it costs, cash-pay and direct pricing, and — if you are denied — appealing a prior authorisation. GoodRx and similar discount tools are worth checking against the manufacturer’s own self-pay price, which is frequently lower.
14 days
The window before your first injection in which most of this can be sorted
4 items
Everything worth buying beforehand: needles, sharps bin, electrolytes, easy food
9 steps
The whole checklist, none of which needs a second appointment
4. Get baseline bloods
This is the step almost everyone skips and later wishes they had not, because without a baseline no later result means anything.
Ask for it explicitly; a Labcorp or Quest draw is inexpensive even self-funded. What to request and why is in bloodwork on a GLP-1, and if you have type 2 diabetes, what to expect the A1c to do is in how much a GLP-1 lowers your A1c.
5. Audit your other medications
Two categories.
Doses that will need reducing as you lose weight — blood pressure medication, insulin, sulfonylureas, sometimes diuretics. Insulin and sulfonylureas in particular need a plan before the first injection, not after the first hypoglycaemic episode.
Things that need monitoring — warfarin, levothyroxine, other narrow-window drugs. And if you are starting tirzepatide while using an oral contraceptive, the four-week rule applies from day one.
Both are covered in GLP-1 drug interactions and the four-week rule.
6. Buy four things
Nothing here is expensive and none of it is marketed at GLP-1 users.
- Pen needles and a sharps container. A hard-sided bin, not a coffee tin.
- An electrolyte product. For the weeks when fluid goes out faster than it goes in.
- A fibre supplement or an osmotic laxative. Start it early rather than in week three — constipation on a GLP-1.
- Food you can face on a bad day. Greek yoghurt, crackers, broth, a protein drink you have already tasted.
If you want to know what the supplement category actually offers before spending anything, start with do you need supplements on a GLP-1.
7. Pick your injection day deliberately
Side effects cluster one to three days after the injection. Choose a day that puts that window somewhere you can afford it — a Thursday or Friday injection puts the worst of it on the weekend for most people.
Then learn the technique properly before the first one: room-temperature pen, pinch, ten-second hold, rotate the site. See where and how to inject, and the schedules in the GLP-1 dose charts.
8. Set the expectations that stop people quitting
- The first month is a tolerance dose. It is not supposed to produce weight loss.
- Week four is the hardest week — a new dose arriving at the low point of the last one.
- Appetite change comes first, scale change comes weeks later — how long Wegovy takes to work.
- Weigh weekly, same morning. Daily weighing hides the trend inside noise.
- Protein and resistance training start in week one, not month six — protein, exercising on a GLP-1, and what to eat.
The week-by-week account of what actually happens is in the first eight weeks, and the full symptom directory is in every side effect ranked.
The fortnight before the first injection is the cheapest fortnight of the whole year, and the one that does the most work.
9. Know the four numbers to call about
Not the whole side effect list. Four situations.
The one-line version
Confirm eligibility, confirm coverage, get bloods, audit your other tablets, buy four cheap things, pick your day, and go in knowing that month one is not a test of whether the drug works.
Most people who stop in the first three months stop for reasons that were entirely foreseeable in the fortnight before they started.