Getting Started
The First 90 Days: A Protocol
Most of the difference between a good outcome and a mediocre one is decided in the first three months, and almost nobody is given a plan. Here is the one I use — week by week, with the labs, the protein numbers, and what to track.
Here is a comparison from the trial data that I think about constantly.
In STEP 1, participants on semaglutide lost a mean of 14.9% of body weight, and the placebo arm lost 2.4%. In STEP 3, where both arms also received intensive behavioural therapy, the semaglutide arm lost 16.0% — about a point better — and the placebo arm lost 5.7%, well over double.
Read that again. Adding a structured programme moved the drug arm slightly and the no-drug arm enormously. Which tells you something precise: the drug handles appetite very well on its own, and it handles nothing else at all. Everything the drug does not do is still sitting there waiting for someone to do it.
Almost nobody starting one of these medications is given a plan for that part. They are given a prescription, a titration schedule, and a follow-up in three months.
So this is the plan. It is what I give my own patients, and it is what I did myself.
Before the first injection
This section is the one people skip and the one that matters most, because these are measurements you cannot recover later. Six months from now, when you want to know whether you are losing muscle, the answer depends entirely on whether anybody measured you in month zero.
Get the baseline labs
- Comprehensive metabolic panel, including liver enzymes and kidney function
- HbA1c, and fasting insulin or C-peptide
- Full lipid panel
- Thyroid function
- Complete blood count, plus ferritin and iron studies
- Vitamin D and B12 — particularly if vegetarian, post-bariatric, or with heavy periods
Get the baseline measurements
- Waist circumference at the level of the navel, measured by someone else if possible
- Blood pressure, seated, properly
- A DXA scan if you can access one. Not essential, often not covered, and the single most useful measurement available to you. It is the only thing that answers “how much of what I lose is fat” rather than “how much lighter am I”
Sort out three practical things
- Who is prescribing, and can you reach them between visits? Most of what goes wrong with these drugs goes wrong because somebody endured something in silence. A ten-minute online intake with no follow-up channel is not adequate supervision for a drug with real contraindications.
- What happens if coverage ends? Ask now, while you are calm.
- Screen yourself against the contraindications. Personal or family history of medullary thyroid carcinoma or MEN2 is absolute. Pregnancy, planned pregnancy, prior pancreatitis, active gallbladder disease and severe gastroparesis all need a real conversation.
Weeks 1–4: the tolerability dose
The starting dose is not therapeutic. Its entire job is to introduce your gut to the drug. Expecting results from it is the fastest route to concluding it is not working.
What to actually do this month:
Start the training now. Two resistance sessions a week, minimum. If you have never lifted, this is the moment to spend money on four sessions with a good trainer — it is the best-value money in the entire enterprise, better than any supplement and arguably better than a month of the drug. Compound movements: squat, hinge, push, pull, carry.
Set the protein target and hit it. 1.2–1.6 g/kg/day, front-loaded at every meal. Do this from week one, while eating is still easy, so the habit is established before appetite disappears.
Get ahead of constipation. It builds quietly and it is the most common reason people quit in month one. Fibre, fluid, movement, and an osmotic laxative if that is not enough. Do not white-knuckle it.
Start logging. This is the part I would argue hardest for.
I use the Zenday App for this and have since my own first injection. The reason it beats a general food tracker is that a general food tracker is built around the premise that eating less is the hard part. On this drug eating less is the easy part. The hard parts are protein, side effects, and never losing track of your injection day — and a GLP-1 companion app is built around those, connecting injection day to how you felt to what you ate rather than just totalling calories. It also runs in a browser rather than sitting as an icon on your home screen, which for a medication this personal is not a small thing.
Whatever you use, log four things: dose and date, side effects by day, protein, and waist.
Weeks 5–8: the first escalation
This is where the drug and you have your first real conversation.
Expect the pattern. Side effects cluster in the 24–72 hours after the injection, typically peak around day three, and settle within a week. Knowing that in advance is most of what makes it bearable.
Find your own pattern, then use it. Two cycles of logging will show you which day is your bad day. Then move your injection so that day lands somewhere convenient — mid-week, rather than on a Saturday you would like to enjoy.
Slow down if you need to. The label explicitly permits delaying escalation if a dose is not tolerated. There is no prize for reaching the maximum on schedule. Staying at a dose for eight or twelve weeks instead of four is a normal clinical decision, and slowing the titration resolves more problems than any remedy does.
Switch to eating on a schedule. This is the single most common failure I see. Appetite suppression means hunger has stopped being a reliable instrument. If you wait to feel hungry, you will not eat, and then you will feel exhausted and blame the drug. Eat at set times whether or not you want to.
Weeks 9–12: the first review
Repeat the measurements. Waist, blood pressure, and a repeat metabolic panel and HbA1c at around twelve weeks.
Expect a plateau and do not panic. A stalled scale between months two and four is usually a recomposition the scale cannot see. Check the waist and the weights on the bar before concluding anything.
Add the third training session if two has become comfortable.
Bring data to the appointment. I have sat on the clinician side of this desk for twenty-one years, and the difference between “I think it’s been going well” and twelve weeks of dose, symptom, protein and measurement data is the difference between a guess and a decision.
The 90-day checklist
| Before | Weeks 1–4 | Weeks 5–8 | Weeks 9–12 | |
|---|---|---|---|---|
| Labs | Full baseline panel | — | — | CMP + HbA1c |
| Waist | Measure | — | Measure | Measure |
| Weight | Record | Weekly | Weekly | Weekly |
| DXA | If accessible | — | — | — |
| Protein | Set target | 1.2–1.6 g/kg | 1.2–1.6 g/kg | 1.2–1.6 g/kg |
| Training | Start | 2×/week | 2×/week | 3×/week |
| Logging | Set up | Dose, symptoms, protein | Find your pattern | Review the trend |
| Dose | — | Starting dose | First escalation | Hold or escalate |
Three things to sort out before day one
Who is prescribing, and are they doing it properly. The single question that reveals most is whether they asked about your family history of medullary thyroid carcinoma — how to choose a GLP-1 prescriber covers what good care includes.
How to inject. You are shown this once, quickly, and then you are alone in a bathroom with a pen. GLP-1 injection technique covers sites, rotation, and the two errors that waste doses.
What happens if you get ill. Agree the medication hold list before you need it, not at 3 a.m. — see sick day rules.
What this protocol is not
It is not individualised to you. It is a reasonable default for a healthy adult starting a GLP-1 receptor agonist for weight management, and it will be wrong in specifics for plenty of people — anyone with type 2 diabetes on insulin or a sulfonylurea, anyone post-bariatric, anyone pregnant or planning to be, anyone with significant kidney or liver disease.
Take it to your own clinician and have them tell you which parts do not apply to you. That conversation is much shorter and much better when you arrive with a plan than when you arrive with a question.
Questions I get about this month
- What labs should I get before starting a GLP-1?
- A reasonable baseline panel is a comprehensive metabolic panel including liver enzymes and kidney function, HbA1c, fasting insulin or C-peptide, a full lipid panel, thyroid function, a complete blood count, and iron studies including ferritin. Vitamin D and B12 are worth adding, particularly if you are vegetarian, have had bariatric surgery, or have heavy periods. Blood pressure and waist circumference should be recorded at the same visit. These are baseline measurements you cannot recover retrospectively.
- How much protein should I eat on a GLP-1?
- During active weight loss, 1.2 to 1.6 grams per kilogram of body weight per day. For a 75 kg adult that is roughly 90 to 120 grams daily, or 30 to 40 grams at each of three meals. This is well above the general population recommendation of 0.8 g/kg, which is a minimum to avoid deficiency in weight-stable adults and is the wrong target for someone in a substantial energy deficit. Eat the protein first at every meal, because stomach capacity is now limited.
- Should I start exercising before or after starting a GLP-1?
- Before, if you can, and at the same time if you cannot. The purpose is preserving lean mass during a rapid energy deficit, and the stimulus that preserves muscle is mechanical load rather than walking. Two resistance sessions a week is the minimum effective dose and three is better, using compound movements loaded heavily enough that the last few repetitions are genuinely hard. Establishing the habit before appetite changes is considerably easier than establishing it during month three.
- What should I track in the first three months on a GLP-1?
- Four things. Dose and injection date, so you never lose the thread. Side effects by day, which reveals your personal post-injection pattern within two cycles. Protein intake, because it drifts downward without anyone noticing. And waist circumference, which is a better instrument than the scale for what is actually changing. Weigh weekly at most, and look at the four-week trend rather than the daily number.
Sources
- 01Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). NEJM, 2021.
- 02Wadden TA et al. Semaglutide as an Adjunct to Intensive Behavioral Therapy (STEP 3). JAMA, 2021.
- 03Cava E, Yeat NC, Mittendorfer B. Preserving Healthy Muscle during Weight Loss. Advances in Nutrition, 2017.
- 04FDA prescribing information, Wegovy (semaglutide) — dose escalation schedule.
- 05Garber CE et al. ACSM position stand: quantity and quality of exercise. Med Sci Sports Exerc, 2011.
Elise Hall, MD
Board-certified internist in Los Angeles, twenty-one years in practice. She writes about GLP-1 medications and metabolic health for people who want the reasoning, not just the conclusion — and publishes her own year on one of these drugs alongside it.
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