How do I take my weekly GLP-1 injection, what should I eat, and which side effects should I watch for?
Take your GLP-1 injection once a week, on the same day each week, just under the skin of your abdomen, thigh, or upper arm, rotating spots. Eat smaller, protein-first meals and drink water through the day. Nausea, constipation, diarrhea, and heartburn are the common side effects; most are mild, show up in the first weeks or right after a dose change, and settle. Anything severe, or anything that will not settle, gets a text to our office the same day.
After two decades of practicing medicine, I can tell you where most GLP-1 setbacks come from: an inconsistent injection day, eating the way you ate before the medication, and toughing out side effects instead of telling us. Here is the short version of what I go over with every patient in the office.
Written by Dr. Ty Tallman, NMD, Integrative Medical Partners, Mesa, AZ. Updated September 9, 2026.
Your weekly injection, step by step
- Same day every week. Any time of day, with or without food. Put it on your calendar with an alarm.
- Choose a site. Abdomen (at least two inches from the navel), the front of the thigh, or the back of the upper arm. Rotate: never the same spot two weeks in a row.
- Clean the skin and let it dry. Insert the needle straight in at 90 degrees, into the fatty layer just under the skin, not into muscle.
- Deliver the full dose. Pen: hold it against the skin until the counter finishes, then count a few extra seconds. Vial and syringe: draw up exactly what we showed you at your visit, push the plunger slowly, and hold a few seconds before withdrawing.
- Dispose safely. Sharps container only. Never reuse or share needles.
- Store it cold. Refrigerated, never frozen, away from heat and light. In Arizona that means it never rides in the car, not even for an hour.
Missed a dose, or want to change your day?
Missed-dose and day-change rules differ by medication and depend on how many days have passed since your last shot. Two things are always true: never take two doses to catch up, and never guess. Text us and we will tell you exactly what to do for your medication.
What to eat on a GLP-1
- Protein first, every meal. Eggs, Greek yogurt, fish, chicken, lean beef, tofu, beans. When appetite drops, protein is what keeps muscle on while fat comes off.
- Smaller plate, slower pace. The medication slows stomach emptying. Stop at comfortably satisfied, not full. Overshooting a meal is the number one nausea trigger.
- Vegetables and fiber, added gradually. A sudden jump in fiber makes constipation and bloating worse, not better.
- Water all day. Sip steadily rather than chugging. Thirst signals fade on a GLP-1, so hydrate on a schedule, especially in Arizona heat.
- Go easy on the trigger foods. Fried and greasy foods, heavy cream sauces, large sugary drinks, carbonation, and alcohol are the ones patients most often tell us set off nausea and heartburn.
- Lift something. Resistance training two or three days a week keeps the weight you lose coming from fat, not muscle.
Side effects: what helps, and when to text us
| Side effect | What usually helps | Text us the same day if |
|---|---|---|
| Nausea | Smaller, blander, cooler meals; eat slowly and stop early; ginger or peppermint tea; stay upright after eating | It lasts more than a few days, you are vomiting, or you cannot keep fluids down |
| Constipation | Water, fiber added gradually, a daily walk, a consistent morning bathroom routine | More than a few days without a bowel movement, or pain and bloating |
| Diarrhea | Fluids with electrolytes; skip greasy foods, sugar alcohols, and dairy for a day or two; small bland meals | More than two days, blood, fever, or dizziness on standing |
| Heartburn | Smaller meals; nothing to eat within three hours of lying down; raise the head of the bed; avoid spicy, acidic, and fried triggers | Daily heartburn, trouble swallowing, or chest pain (chest pain is an emergency: call 911) |
Most of these show up in the first weeks or right after a dose change and then fade. The mistake is toughing it out. Small adjustments to the plan, the timing, or the dose early on keep people on treatment; two weeks of untreated nausea is what makes people quit. For the fuller picture, read what to expect from GLP-1 side effects and why dehydration hits harder on a GLP-1.
Call right away for these
Severe or persistent stomach pain, especially pain that radiates to your back. Vomiting that will not stop. Signs of dehydration: dizziness, very dark urine, a racing heart. Yellowing of the skin or eyes. Sudden vision changes. Rash, or swelling of the face or throat. These are uncommon, but they are not wait-and-see. If it feels like an emergency, call 911 first and text us second.
What the evidence says
In the pivotal 68-week trial of weekly semaglutide for weight, gastrointestinal side effects were the most common complaint, affecting roughly three out of four people on the medication versus about half on placebo. Most were mild to moderate, showed up during dose escalation, and resolved without stopping treatment; about 7% stopped because of side effects, versus 3% on placebo. Pooled data across the first three STEP trials put nausea near 44% (versus 16% on placebo), diarrhea near 30%, and constipation near 24%, with nausea peaking around week 20 and declining after. Tirzepatide trials show the same pattern. The honest takeaway: side effects are common, mostly manageable, and mostly temporary, and the people who do best are the ones who stay consistent and stay in touch.
Our 30-day rule
Every GLP-1 patient in our office checks in every 30 days, and dose adjustments happen at those check-ins. That means side effects get addressed before the next step up, not after. Your plan is individualized and provided through our office: the medication, the eating plan, and the lab work that tells us whether the weight you are losing is the weight you want to lose. Adjustments are based on how you feel and what your labs show, never on a calendar alone.
Common questions
Can I take my shot at night?
Yes. Any time of day works. Keeping the same day each week matters more than the hour.
Do I inject before or after eating?
Either. Food does not change how a weekly GLP-1 is absorbed.
Why do I feel worse the week my dose goes up?
Each increase slows stomach emptying a little more, so the meal size that worked last month can be too big this month. Shrink portions for a week and tell us. If it does not settle, we can hold the dose where it is for longer.
Can I drink alcohol on a GLP-1?
It is one of the most common nausea and heartburn triggers patients report, and it works against your results. If you drink, keep it small and never on an empty stomach.
How long do side effects last?
Usually days to a couple of weeks around each dose change, then they ease. Anything lasting longer than that is worth a message.
Do I need labs?
Yes. Labs tell us what the scale cannot: whether you are losing fat or muscle, how your blood sugar and liver are responding, and whether anything else needs attention. That is the difference between guessing and knowing.
Related reading: GLP-1 health benefits beyond the scale and medical weight loss in Mesa, AZ.
Text us at 480-485-2197 to schedule, or call. Quick response, real scheduling, no phone tree.
To Health and Wellness, Dr. Ty Tallman
References
- New England Journal of Medicine, 2021 — once-weekly semaglutide in adults with overweight or obesity (STEP 1)
- Diabetes, Obesity and Metabolism, 2022 — gastrointestinal tolerability of once-weekly semaglutide and its relationship to weight loss
- New England Journal of Medicine, 2022 — tirzepatide once weekly for the treatment of obesity (SURMOUNT-1)