What to note in your first week on a GLP-1

Before the first injection

The Wegovy® label asks prescribers to tell patients which presentation they will receive, train them on that specific one before treatment starts, and repeat the training if the presentation changes. After training, a patient may self-inject if the healthcare provider decides it can be done properly; the FlexTouch® pen is not recommended for self-injection by people who are visually impaired ^[1].

The Medication Guide then lists what to tell your provider first: problems with your pancreas or kidneys, type 2 diabetes with a history of diabetic retinopathy, surgery or procedures that use anesthesia or deep sedation, pregnancy or plans for it, and breastfeeding. It says to stop Wegovy® 2 months before a planned pregnancy ^[1].

It also asks for a full list of your medicines, vitamins and herbal supplements, because semaglutide delays how fast the stomach empties, which can change how some medicines that must move through it quickly are absorbed. If you have type 2 diabetes, it asks you to check your blood sugar before starting and during treatment, and to discuss how to recognise and treat low blood sugar, especially with insulin or a sulfonylurea ^[1].

Which product you have

The weekly injections differ in device, in where the label allows the injection and in how quickly the medicine peaks. The table puts the four most common side by side, with Wegovy® tablets for comparison:

Dose day: checking the pen

The single-dose Wegovy® pen instructions start with washing your hands and checking three things: that the pen does not look used or broken, that the medicine in the window is clear and colorless, and that the expiration date has not passed. If it fails any check, they ask you to contact Novo Nordisk. Air bubbles are normal and do not affect the dose. Check, too, that the strength on the pen is the one prescribed ^[1]. Tirzepatide is described differently: clear and colorless to slightly yellow ^[3][4].

The instructions allow the front of the thighs, the lower stomach at least 2 inches (5 cm) from the belly button, or the upper arm. They say to avoid skin that is tender, bruised, red or hard, and areas with scars or stretch marks. You may use the same body area each week, but not the same spot; clean the skin and let it dry first ^[1].

During the injection

With the cap removed, you press the pen firmly against the skin and keep pressing. The instructions describe two clicks, the first when the injection starts and the second while it continues, an injection that takes about 5 to 10 seconds, and a yellow bar that moves in the window. Lift only once the yellow bar has stopped; lifting early, or not pressing firmly throughout, can leave medicine on the skin and a partial dose. The needle cover locks afterwards, so an injection cannot be paused and restarted ^[1].

If a little blood appears, press lightly with gauze or a cotton ball. The used pen goes straight into a sharps disposal container, not the household trash or recycling ^[1]. The FDA suggests following your community’s rules once the container is about three-quarters full ^[5].

The days after: what to notice

Semaglutide injection reaches its highest level 1 to 3 days after a dose, and tirzepatide between 8 and 72 hours after ^[1][2][3][4]. The Wegovy® Medication Guide lists the most common side effects as nausea, stomach pain, diarrhea, vomiting, constipation, headache, tiredness, dizziness, belching, bloating, gas, heartburn, upset stomach, stomach flu, changes in skin sensation and hair loss, with low blood sugar in people with type 2 diabetes. It asks you to mention any side effect that troubles you or lingers ^[1].

Short daily notes are enough: appetite, any nausea and when it began, bowel changes, sleep and energy, each with how many days it came after the injection. A pattern shows up faster on paper than in memory, and the Wegovy® label reports its stomach-related reactions most often during the weeks of dose escalation ^[1].

Fluids matter more than usual

The Medication Guide connects stomach upset with dehydration, and dehydration with possible kidney problems. It says drinking fluids helps reduce that chance, and that if nausea, vomiting or diarrhea keeps going you should let your healthcare provider know right away ^[1]. It also lists severe stomach problems that will not go away as something to report ^[1].

A simple tally of drinks and of any vomiting or diarrhea gives your clinician something concrete if you call.

Storage and the next dose

Unused single-dose pens and syringes belong in the refrigerator at 2–8°C (36–46°F), away from the cooling element and never frozen. If needed, before the cap comes off, they may be kept out of the fridge, at no more than 30°C (86°F), in the carton for up to 28 days. A FlexTouch® pen, once in use, may be kept at 15°C to 30°C or in the fridge for up to 56 days, with the needle removed after each injection ^[1].

The next injection is due on the same weekday. The Medication Guide allows a change of day as long as the last dose was 2 or more days before, and gives its own rule for a missed dose, which a separate article compares across labels ^[1].

A simple first-week log

The week fits in a few lines: the product and strength, the dose date, time and site; short daily notes on appetite, nausea, bowels, drinks and sleep; a starting weight if you track it; and the questions you want to ask at the next appointment. Keep the pack leaflet with the log, since its instructions are the ones for your product.

Wegovy®, Ozempic® and FlexTouch® are registered trademarks of Novo Nordisk A/S. Mounjaro®, Zepbound® and KwikPen® are registered trademarks of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.

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