Dosing and concentration
A commonly studied adult weight-management injection schedule begins at 0.25 mg weekly for four weeks, then uses four-week stages of 0.5, 1.0 and 1.7 mg before 2.4 mg weekly. This describes that specific schedule, not a universal maximum or instructions for oral products. Escalation depends on tolerability and the prescribing plan; it is not a race to the largest dose.
A milligram is an amount of peptide. A millilitre is a volume of liquid. Syringe markings describe volume, not semaglutide strength. If a documented solution contains 2 mg/mL, 0.25 mL contains 0.5 mg. This is arithmetic, not a recommended concentration or personal dose. On a U-100 syringe, 0.25 mL occupies 25 marked units; those are not 25 international units of semaglutide.
After a long interruption, restarting at the previous high amount can be poorly tolerated. Use the missed-dose and restart directions for the actual product with the treating clinician. Do not compensate for uncertain delivery by immediately repeating an injection.
Preparation and reconstitution
A ready-to-use pen or solution does not require bacteriostatic water. Adding water changes its concentration and can interfere with the device. Keep the original medicine and its instructions together.
A lyophilised vial contains freeze-dried material. Reconstitution means dissolving it in a specified diluent to reach a specified final concentration. Bacteriostatic water contains a preservative, usually benzyl alcohol; it is not a sterilising treatment for the peptide. A research vial does not become an approved injectable medicine because it dissolves clearly.
The preparation instructions must identify the exact peptide form, compatible diluent, volume, resulting concentration and storage limit. Where a clinician has supplied a documented injectable preparation, have the matching syringe and measuring technique demonstrated. Do not choose a water volume solely to make an online “units” chart fit.
Administration
Clinical injections are given subcutaneously, into fatty tissue beneath the skin. The abdomen, thigh and upper arm are used with appropriate product instructions. Injecting the abdomen does not preferentially remove abdominal fat. Rotate locations, and avoid bruised, inflamed, scarred or damaged skin.
Wash hands, prepare on a clean surface and use a new sterile needle and syringe or the specified pen needle. Never share a pen, even with a new needle. Let cleaned skin dry, follow the device's insertion and hold-time instructions, and put used sharps directly into a sharps container. Needle length and technique should suit the device and body tissue; a vial guide is not a pen guide.
Oral versus subcutaneous delivery
Ordinary swallowed peptides face acid, digestive enzymes and a barrier to absorption through the gut wall. Oral semaglutide tablets address this with a specialised formulation that includes an absorption enhancer, SNAC. The formulation enables uptake through the stomach lining near the dissolving tablet. This is why oral semaglutide can work despite a much smaller fraction reaching the circulation.
Oral dosing instructions about fasting, water and time before food are part of that delivery system. Swallowing injectable liquid or putting lyophilised peptide into a capsule does not recreate it. Oral semaglutide is intended to reach the bloodstream, not primarily to treat the gut lining locally.
Subcutaneous delivery bypasses digestive breakdown. Greater absorption does not mean an oral dose can be converted to an injection by a simple percentage; the entire dosing schedule and formulation differ.
Half-life
Injected semaglutide has a half-life of about one week. Levels fall gradually, and peptide can remain in the circulation for several weeks after stopping. A missed day does not mean the previous weekly dose has disappeared.
Storage
Storage belongs to the presentation. For example, the documented U.S. single-dose Wegovy injection instructions specify refrigeration at 2–8°C, protection from light and no freezing; their limited room-temperature allowance is not a rule for every semaglutide vial or tablet.
Tablets need their own moisture-protection instructions. Keep any prepared vial labelled with concentration, preparation or opening date and its assigned discard date. A refrigerator slows many degradation processes but cannot reverse freezing, heat damage or contamination. Do not apply a pen's expiry allowance to reconstituted research material.
Contraindications and side effects
Semaglutide injection labels contraindicate use with a personal or family history of medullary thyroid carcinoma, MEN2, or serious allergy to the product. These are specific conditions, not a statement that every thyroid disorder is equivalent. Pregnancy planning matters: the documented injection label advises stopping at least two months before a planned pregnancy.
Nausea, vomiting, diarrhoea and constipation deserve attention when persistent. Severe abdominal pain, inability to keep fluids down, fainting or signs of an allergic reaction need prompt medical assessment. Tell the clinician about pancreatitis, gallbladder problems, severe stomach-emptying difficulty, kidney disease and diabetic eye disease. Insulin or sulfonylureas can increase hypoglycaemia risk when combined with improved glucose control.
Before surgery or deep sedation, tell the anaesthesia team about semaglutide and recent gastrointestinal symptoms. Do not invent a stopping interval: the team should plan around the procedure and current condition.
Tracking progress and common questions
Record the actual amount and formulation, appetite, bowel symptoms, hydration and a consistent weight trend. Note dose changes beside symptoms so a clinician can review the timing. A plateau can reflect normal variation, constipation or a longer-term energy balance change; it is not an automatic instruction to escalate.
“Will I regain weight after stopping?” Appetite commonly returns, and weight regain has been observed after treatment withdrawal. Plan maintenance support before stopping rather than viewing treatment as a brief detox. “Should I never feel hungry?” No. Normal hunger and the ability to eat nourishing meals remain useful signals.