Semaglutide is one of the most prescribed medications in Canada and one of the most misunderstood. Patients expect immediate results, don't see them, and stop too soon. The medication works on multiple distinct timelines. Here's what to expect at each one.
How long does Ozempic take to work?
Most patients notice appetite suppression within 1 to 2 weeks. Measurable weight loss starts at 4 to 8 weeks. Clinically meaningful results accumulate over months 3 to 6. Three timelines run in parallel: behavioural change, dose escalation, and physiological adaptation. If you stop too early, you lose the medication's strongest phase.
When does appetite suppression start?
Dose: 0.25 mg semaglutide weekly.
Within 1 to 2 weeks of the first injection. You feel satisfied with smaller meals, food cravings drop, and the constant background thought of "what's for lunch" quietens down. Semaglutide mimics GLP-1, a natural hormone that signals fullness and dampens hunger.
Common early side effects: mild nausea, constipation, and digestive sluggishness. Smaller meal portions, plenty of water, and avoiding high-fat foods around injection time help. Most of this resolves by week three.
When do I see real weight loss?
Dose: 0.5 mg semaglutide weekly.
Measurable weight loss usually starts between weeks 4 and 8. At week four the protocol typically increases to 0.5 mg. Appetite suppression intensifies and most patients see measurable weight loss, somewhere between one and two pounds a week depending on diet and activity.
This is the phase patients describe as "Oh, this is real." The mental preoccupation with food largely disappears. But Ozempic is not a passive intervention: the medication reduces hunger, what you do with that reduced hunger determines progress.
How much weight will I lose in 3 to 6 months?
Three-month mark: typically 5 to 8% of starting body weight. Someone starting at 220 lb would lose roughly 11 to 18 lb.
Six-month mark: roughly 10 to 15% of starting body weight. The STEP 1 trial of Wegovy (same active ingredient) showed average weight loss of 14.9% over 68 weeks.
Individual variation is significant. Medical history, starting weight, diet quality, activity level, and consistency all matter.
What if I hit a plateau?
Most patients hit a plateau between months six and twelve as the body reaches a new equilibrium. This is normal physiology, not a treatment failure.
One critical thing to understand for the long run: weight typically returns within six to twelve months of stopping Ozempic if no lifestyle changes have been built up during treatment. The medication manages hunger signals; it doesn't permanently change underlying biology. Success depends on cementing behavioural changes during the months it's working.
What your pharmacist monitors
- Drug interactions (especially with diabetes and blood-pressure medications)
- Side-effect patterns that suggest a slower titration
- Injection technique
- Progress and timing of dose escalation
We stock multiple GLP-1 options: Ozempic, Wegovy, Mounjaro, Saxenda, and Contrave. Switching between them is sometimes the right call.
What are the common side effects?
Mostly gastrointestinal: nausea, stomach discomfort, constipation, or loose stools. Dose-dependent and typically fade within one to two weeks at each new dosage level. Rare serious effects include pancreatitis and gallbladder disease, which is why we monitor.
What if I miss a weekly dose?
Within 5 days: take it as soon as you remember, then resume your regular weekly schedule.
More than 5 days: skip the missed dose and resume your normal schedule. Don't double up.
Talk to a pharmacist
If you're starting Ozempic, hitting a plateau, or considering switching to Wegovy or Mounjaro, walk into our consultation room. The pharmacist running the program is the same person you'll see at every follow-up.