Who this guide is for
This guide is for men starting semaglutide for weight loss under a provider’s care, or about to. It maps the first four weeks so you know what is normal, what is not, and what the first check-in is for.
The first month is deliberately gentle. The Wegovy label starts at 0.25 mg once weekly for four weeks, then steps up every four weeks (0.5 mg, 1 mg, 1.7 mg) toward a maintenance dose. Your provider sets your actual dose and pace. The point of the opening month is to let your stomach and gut adapt, so the dose that follows is tolerable.
Before the first injection, your provider will have screened for reasons not to start. The label’s boxed warning rules out men with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2 (MEN 2), and a past serious allergic reaction to semaglutide is another firm no. A history of pancreatitis, gallbladder disease, kidney problems or diabetic eye disease does not always rule it out, but it changes how closely the first month is watched. Our page on who should not take semaglutide goes through the list.
If your semaglutide comes as a compounded vial rather than a branded pen, the dose is drawn up in syringe units, and the FDA has received reports of hospitalizations linked to measuring errors with compounded semaglutide. Confirm the exact number of units with your provider before the first dose, and write it down. Our injection guide walks through pen and vial technique.
Weeks one to four, mapped
| Week | Dose (label schedule) | Appetite | Common side effects | Your focus |
|---|---|---|---|---|
| 1 | First 0.25 mg injection | Some men feel full sooner within days; others notice little | Mild nausea in the 1 to 2 days after the shot; burping or heartburn | Small meals, steady fluids, baseline weight and waist |
| 2 | Second 0.25 mg injection | Smaller portions, less snacking, quieter food thoughts for many | Nausea pattern becomes predictable around injection day | Protein at each meal, note what triggers queasiness |
| 3 | Third 0.25 mg injection | Appetite change usually clearer | Constipation may start to build as you eat less | Fiber from food, more water, daily walks |
| 4 | Fourth 0.25 mg injection | Settling into a new normal | Side effects often milder than week one | Check-in to review tolerance and decide the next step |
Nothing in this table is a reason to change your own dose. If a week goes badly, call; do not skip, split or double a dose without instructions.
Appetite: what changes and how to eat with it
Semaglutide lowers body weight mainly by reducing how much you eat. In practice, men describe feeling full after half a plate, less pull toward late-night snacks and fewer intrusive thoughts about food.
That change brings two risks in month one: eating too little protein and not drinking enough. A few habits help:
- Eat smaller meals more often. A 2025 joint advisory on nutrition during GLP-1 therapy recommends smaller, more frequent meals to ease nausea.
- Lead with protein. Eat the protein part of the plate first, before you fill up. Our guide to eating and training to keep muscle on a GLP-1 sets a target.
- Stop at the first sign of fullness. Pushing past it is the most common trigger for vomiting in the early weeks.
- Go easy on greasy, fried and very rich food, especially in the day or two after the injection.
- Drink through the day, not just with meals.
The nausea and constipation pattern
Gastrointestinal side effects are the main story of the first month, and they are common. In the trials behind the Wegovy label, nausea affected 44 percent of people on the full 2.4 mg dose compared with 16 percent on placebo, and constipation 24 percent compared with 11 percent. The joint advisory notes that these effects are most likely when a GLP-1 is started or the dose is raised, and tend to ease once a dose is stable.
Nausea usually appears within a day or two of each injection and fades over the following days. The advisory points out that it often strikes in the morning or after long gaps without food, so a small breakfast can help. Ginger, bland foods, eating slowly and not lying down right after a meal are practical measures. Our answer on how to stop nausea on semaglutide goes further.
Constipation tends to build more slowly, often in weeks two to four, because you are eating less and food moves more slowly. Fluids, fruit and vegetables, a daily walk and a gradual increase in fiber help. If several days pass with no bowel movement, call rather than waiting; see constipation on a GLP-1.
Fluids matter more than usual. The Wegovy label warns that kidney injury has occurred in people who became dehydrated from nausea, vomiting or diarrhea, mostly during starting and dose increases.
The week-four check-in: deciding the first dose step
Before your fifth dose, your provider reviews how the month went. It is a decision point, not a formality.
What gets reviewed:
- How many days of nausea, vomiting or diarrhea you had after each injection
- Bowel habits and any constipation
- How much you are eating and drinking, including protein
- Weight and waist change since baseline
- Energy, dizziness, mood and sleep
- Any new medicines, procedures or planned surgery
How the decision usually goes: if side effects were mild and manageable, the next step on the schedule is usually discussed. If they were rough, the label allows delaying the escalation for four weeks, and staying at the current dose longer is a normal choice, not a setback.
Checklist and warning signs
- I know my exact dose, in mg and, for a vial, in syringe units.
- I inject on the same day each week.
- I recorded my starting weight and waist.
- I am eating protein at each meal and drinking through the day.
- I have a plan for nausea and constipation.
- My week-four check-in is booked.
When to call the clinic: vomiting that lasts more than a day, nausea that keeps you from eating at all, no bowel movement for several days, dizziness when standing, or low mood. Ask too if you are unsure whether you injected the right amount.
When to call 911 or go to the ER: severe stomach pain that does not go away, with or without vomiting, especially if it spreads to the back; pain in the upper right abdomen with fever or yellowing of the skin or eyes; signs of a severe allergic reaction such as swelling of the face or throat or trouble breathing; or fainting. MedlinePlus lists these among the serious effects that need immediate care. The full list is in our guide to GLP-1 warning signs.
How Ultimate Male supports your first month
At Ultimate Male, semaglutide is part of a medical weight loss plan that starts with an evaluation, labs and a body composition analysis at our San Gabriel or Downey clinic. You leave the first visit with your dose written down, a way to reach the clinic and a check-in on the calendar.
Between visits, call with questions rather than guessing; changing your own dose is never the fix. At the check-in, your provider looks at your symptoms and numbers together and decides with you whether to step up, hold or adjust. Ready to begin? Call 626-319-5261 for a free 10-minute chat, or book a weight loss consultation online.
