A complete guide to how it works, who it's for, and what to realistically expect.
01
Semaglutide is a medication that belongs to a class called GLP-1 receptor agonists. GLP-1 is a hormone your body produces naturally after eating - it signals fullness to your brain, slows digestion, and helps regulate blood sugar. Semaglutide mimics that hormone, but unlike the natural version which clears your system within minutes, it's been structurally modified to remain active for a full seven days. That's why it's administered just once a week.
It was originally developed to manage blood sugar in people with type 2 diabetes. During those early trials, consistent and significant weight loss emerged as a secondary finding - one that ultimately shaped an entirely new direction for the medication. Today it's one of the most researched compounds in modern medicine, with over 458 clinical trials registered globally spanning weight loss, cardiovascular health, kidney function, and beyond.
The sections below will walk you through how it works, who it's appropriate for, and what to realistically expect - so you can go into any conversation with a provider already informed.
02
Semaglutide doesn't work through one single mechanism - it acts across multiple systems at once, which is a large part of why its clinical results have been so consistent.
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Semaglutide activates GLP-1 receptors in the hypothalamus - the region that governs hunger and satiety. It stimulates neurons that signal fullness while simultaneously suppressing the neurons that drive hunger. The practical effect is a meaningful, sustained reduction in appetite that isn't dependent on willpower. Many people describe it as the constant background noise around food and cravings simply quieting down. Research also shows that semaglutide influences food reward pathways, reducing the pull toward high-fat, energy-dense foods specifically - not just overall hunger.
Semaglutide slows gastric emptying, meaning food moves from the stomach to the small intestine more gradually than usual. This extends the feeling of fullness after meals and blunts the blood sugar spikes that often trigger energy crashes, and the hunger that follows them. It's also the primary reason nausea occurs in the early weeks of treatment, as the body adjusts to a slower digestive rhythm.
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Semaglutide enhances insulin secretion in a glucose-dependent manner - meaning it only prompts insulin release when blood sugar is actually elevated, not at baseline. This makes it safe from hypoglycemia risk in people who aren't on insulin or other blood sugar-lowering drugs.
Together, these mechanisms create a consistent caloric deficit without requiring extreme dietary restriction - which is why the weight loss outcomes in clinical trials have been both significant and sustained over time.
Explore our Weight Loss Treatments
03
This is one of the most common points of confusion around this medication, and the answer is straightforward: all three contain the same active ingredient. Ozempic, Wegovy, and compounded semaglutide are all semaglutide - what differs is the approved dose, the clinical indication each is licensed for, and the cost.
Ozempic was the first to market, approved in 2017 for blood sugar management in type 2 diabetes. Its standard maximum approved dose is 1.0 mg weekly, with a higher 2.0 mg dose added by the FDA in 2024 for patients needing additional blood sugar control. Weight loss occurs as a well-documented secondary effect, but it was never the primary intended use.
Wegovy is the dedicated weight management formulation, approved in 2021 at a higher maximum dose of 2.4 mg weekly. That higher dose is what was studied in the large-scale STEP trials and linked to the more significant weight loss outcomes seen in those results. If weight loss is the goal, 2.4 mg is the clinically relevant dose.
Compounded semaglutide contains the same active molecule, prepared by a licensed compounding pharmacy and prescribed by a board-certified provider. It follows the same titration protocol used in the STEP programme - starting low and increasing gradually, and is typically available at a price that doesn't require insurance to be accessible.
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04
Semaglutide is approved for adults with a BMI of 30 or higher, or a BMI of 27 or higher alongside at least one weight-related health condition - such as high blood pressure, high cholesterol, type 2 diabetes, or sleep apnoea. These criteria, drawn from the Wegovy FDA prescribing information, form the clinical baseline most providers use when evaluating eligibility.
That said, BMI is a starting point, not the whole picture. A provider will also review your medical history, current medications, and overall health before determining whether semaglutide is the right fit for you.
Semaglutide is not appropriate for everyone. It is contraindicated in people with:
A personal or family history of medullary thyroid carcinoma (MTC)
Multiple Endocrine Neoplasia syndrome type 2 (MEN2)
A history of pancreatitis
Severe gastrointestinal conditions or gastroparesis
A known allergy to semaglutide or any component of the formulation
Current use of another GLP-1 receptor agonist
If any of the above apply to you, disclose them during your intake - that's exactly what the provider consultation is there for.
05
Semaglutide doesn't start at full strength. The standard protocol begins at 0.25 mg weekly - a dose designed entirely for your body to adjust, not to produce results. Every four weeks the dose increases, and most of the meaningful weight loss happens at the higher therapeutic doses of 1.7 mg and 2.4 mg. That gradual build isn't a delay - it's what keeps side effects manageable and keeps people on the medication long enough to see real change
The standard titration runs: 0.25 mg for weeks 1-4 (adjustment phase - don't expect weight loss yet), 0.5 mg for weeks 5-8 (appetite suppression begins), 1.0 mg for weeks 9-12 (weight loss typically becomes visible), 1.7 mg for weeks 13-16 (cravings reduce significantly), and 2.4 mg from week 17 as the maintenance dose. Most meaningful results build from months 3 to 4 onwards, once therapeutic doses are reached.
Results aren't linear and they aren't identical for everyone. Plateaus are normal and don't mean the medication has stopped working. Your HealthHub provider reviews your progress throughout and can adjust your dose based on how your body responds.
Compounded semaglutide contains the same active molecule, prepared by a licensed compounding pharmacy and prescribed by a board-certified provider. It follows the same titration protocol used in the STEP programme - starting low and increasing gradually, and is typically available at a price that doesn't require insurance to be accessible.
Read: What to expect in your first 3 months?
06
The most frequently reported side effects with semaglutide are gastrointestinal - nausea, constipation, and diarrhea being the most common. They are dose-dependent and almost always most pronounced in the first few weeks and after each dose increase. For the majority of people, they improve significantly as the body adjusts. In the STEP 1 clinical trial, nausea was reported in around 44% of participants at the 2.4 mg dose, but only 4.3% permanently discontinued treatment because of gastrointestinal side effects - meaning over 95% of those who experienced them continued and completed the trial.
Contact your provider promptly if you experience severe or persistent abdominal pain, prolonged vomiting, signs of an allergic reaction, or any symptoms that feel serious. These are uncommon but require proper assessment.
07
HealthHub offers semaglutide in two formats: a once-weekly subcutaneous injection and a daily sublingual liquid placed under the tongue. Both contain the same active compound - the difference is in how it enters your bloodstream and what the evidence currently looks like for each. Your provider will walk you through both options during your consultation and recommend the format that makes the most sense for your situation.
See our Semaglutide Programme and Pricing
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