Semaglutide
Also known as: Ozempic, Wegovy, Rybelsus
Key Facts: Semaglutide
- Category
- Weight Loss
- FDA Status
- FDA Approved
- Clinical Status
- FDA Approved - Multiple indications
- Administration
- Subcutaneous injection weekly, or oral (Rybelsus)
- Typical Dose
- 1-2.4 mg weekly (after titration)
- Frequency
- Once weekly
- Evidence Level
- FDA Approved
- Duration
- Long-term / chronic use
What to Expect
A GLP-1 receptor agonist FDA-approved for type 2 diabetes and chronic weight management. One of the most effective pharmaceutical weight loss interventions available.
Mechanism of Action
Semaglutide mimics the GLP-1 hormone, slowing gastric emptying, increasing insulin secretion, reducing glucagon release, and acting on brain appetite centers to reduce hunger and increase satiety. It has 94% amino acid similarity to human GLP-1.
Research Summary
STEP trials demonstrated average weight loss of 15-17% body weight over 68 weeks. SELECT trial showed 20% reduction in major cardiovascular events. Proven efficacy for glycemic control in type 2 diabetes with A1C reductions of 1.5-2%.
FDA Approval Studies
This peptide is FDA approved. Below are the key clinical trials that supported its approval.
STEP Program (Semaglutide Treatment Effect in People with obesity)
Novo Nordisk • Phase 3
4,500+ participants across STEP 1-4 trials
68 weeks
Percent change in body weight from baseline
- ✓STEP 1: 14.9% average weight loss vs 2.4% placebo
- ✓STEP 2 (with diabetes): 9.6% weight loss vs 3.4% placebo
- ✓STEP 3 (with lifestyle intervention): 16.0% weight loss
- ✓STEP 4: Continued treatment maintained weight loss vs regain with placebo
SUSTAIN Program (Semaglutide Unabated Sustainability in Treatment of Type 2 Diabetes)
Novo Nordisk • Phase 3
8,000+ participants across SUSTAIN 1-10 trials
30-104 weeks
HbA1c reduction from baseline
- ✓Superior HbA1c reduction vs comparators (sitagliptin, exenatide, dulaglutide)
- ✓Significant cardiovascular benefit shown in SUSTAIN-6
- ✓26% reduction in major cardiovascular events
- ✓Consistent weight loss of 4-6 kg across trials
Dosing Information
Typical Dosingⓘ
Community experience
1-2.4 mg weekly (after titration)
0.25-2.4 mg weekly
Once weekly
Titrate up slowly over 16-20 weeks to minimize GI side effects. Start at 0.25 mg, increase every 4 weeks. Many stay at 1 mg if tolerating well.
Research Dosingⓘ
Scientific studies
Prescribed doses per FDA labeling
Doses from Studies
0.25mg weekly (starting)
FDA Label - Ozempic/Wegovy - Initial dose for all patients ↗
0.5mg weekly
1.0mg weekly
Duration
Long-term / chronic use
Administration
Subcutaneous injection weekly, or oral (Rybelsus)
Timing & Administration
Best Time to Take
Morning, same day each week
Once weekly, same day and time
Food Recommendation
With or without food
Why This Timing?
Weekly injection should be at a consistent time. Morning allows monitoring for any side effects during waking hours.
Possible Side Effects
Not everyone experiences these effects. Individual responses vary based on dosage, duration, and personal factors.
- ●Nausea (common, usually transient)
- ●Vomiting
- ●Diarrhea
- ●Constipation
- ●Abdominal pain
- ●Headache
- ●Fatigue
- ●Injection site reactions
- ●Hypoglycemia (with insulin/sulfonylureas)
- ●Gallbladder problems
- ●Pancreatitis
- ●Acute kidney injury
- ●BOXED WARNING: Thyroid C-cell tumors - contraindicated with MTC/MEN 2
References
Related Peptides
Peptides commonly compared with Semaglutide or used in similar applications.
Tirzepatide
FDAA dual GIP/GLP-1 receptor agonist representing the next generation of incretin-based therapies. Shows superior weight loss compared to semaglutide in head-to-head trials.
Weight LossRetatrutide
Clinical TrialsA triple agonist targeting GLP-1, GIP, and glucagon receptors. Represents the next evolution beyond dual agonists like tirzepatide, showing unprecedented weight loss in trials.
Weight LossAOD-9604
Clinical TrialsA modified fragment of human growth hormone (amino acids 177-191) studied for fat metabolism effects without the broader hormonal effects of full GH.
Weight LossLiraglutide
FDAAn FDA-approved GLP-1 receptor agonist for type 2 diabetes and chronic weight management. The predecessor to semaglutide with daily dosing.
Weight LossCagrilintide
Clinical TrialsA long-acting amylin analog developed by Novo Nordisk for obesity treatment. Works through a different mechanism than GLP-1 agonists, targeting amylin receptors in the brain to reduce appetite and slow gastric emptying. Shows enhanced weight loss when combined with semaglutide (CagriSema).
Weight LossDulaglutide
FDAAn FDA-approved weekly GLP-1 receptor agonist for type 2 diabetes. Fused to an Fc antibody fragment for extended duration of action.
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Educational Information Only
This information is provided for educational purposes only and is not intended as medical advice. Always consult with qualified healthcare providers before making any decisions about peptides or other substances. The protocols listed reflect doses observed in research studies, not recommendations.