Overview
Semaglutide is an FDA-approved synthetic 31-amino acid analog of glucagon-like peptide-1 (GLP-1), modified with a C18 fatty acid chain via a linker to albumin for extended half-life (~7 days). Originally approved for type 2 diabetes (Ozempic, 2017), it received approval for chronic weight management (Wegovy, 2021) after demonstrating ~15% average body weight reduction in the STEP-1 trial. It has since demonstrated remarkable cardiovascular benefits (20% reduction in MACE in the SELECT trial) and is being investigated for kidney disease, NASH, Alzheimer's disease, and addiction.
Mechanism of Action
Semaglutide activates GLP-1 receptors (GLP-1R) expressed in the pancreas, brain (hypothalamus, brainstem), heart, kidney, and other tissues. In the pancreas, glucose-dependent insulin secretion is increased while glucagon suppression reduces hyperglycemia. In the hypothalamus and brainstem, GLP-1R activation reduces appetite and food intake by modulating arcuate nucleus satiety neurons and reducing reward-circuit food cue responses. Peripheral effects include slowed gastric emptying (enhancing satiety), improved insulin sensitivity, reduced liver fat, and direct cardiovascular protection.
Potential Benefits
- FDA-approved: type 2 diabetes (Ozempic), obesity (Wegovy), cardiovascular risk reduction
- ~15% average body weight reduction in STEP-1 trial
- 20% reduction in major adverse cardiovascular events in SELECT trial
- 1.5% HbA1c reduction in type 2 diabetes
- Reduced all-cause mortality in cardiovascular risk patients
- Kidney disease progression reduction (Phase III data)
- Emerging evidence for Alzheimer's disease, NASH, and alcohol use disorder
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Typical Range | 0.25-2.4 mg/week (subcutaneous); 3-14 mg/day (oral) |
| Beginner | 0.25 mg/week for 4 weeks (titration start) |
| Intermediate | 0.5-1 mg/week |
| Advanced | 1.7-2.4 mg/week (FDA-approved obesity dose) |
| Cycle Duration | Ongoing; no defined off-cycle for therapeutic use |
| Cycle Off | Discontinuation results in weight regain; not intended for cycling |
FDA-approved titration: 0.25 mg/week → 0.5 mg (wk 5) → 1 mg (wk 9) → 1.7 mg (wk 13) → 2.4 mg (wk 17). Oral semaglutide taken on empty stomach with ≤4 oz water.
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Subcutaneous Injection High
Once-weekly injection into abdomen, thigh, or upper arm; preferred route; ~89% bioavailability
Oral Low
Oral Rybelsus uses SNAC absorption enhancer; bioavailability ~10% with SNAC; must be taken fasting with minimal water
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Stacking Protocols
Popular research stacks involving Semaglutide:
Lean Mass Preservation Stack
GLP-1-driven weight loss with GH-mediated lean mass preservation
GH secretagogues help offset the lean muscle mass loss that can accompany significant GLP-1-driven weight reduction.
Cardiometabolic Stack
Cardiovascular risk reduction and cellular energy restoration
Semaglutide's proven CV benefits combined with NAD+ supplementation for comprehensive metabolic health.
Gut Health Stack
GLP-1 agonism with GI cytoprotection to reduce GI side effects
BPC-157 may help manage GI discomfort common with GLP-1 agonist initiation through its gut-protective properties.
Explore our complete Peptide Stacking Guide for more combinations and safety considerations.
Reconstitution
| Typical Vial Size | 2mg/1.5ml, 4mg/3ml pen device, Oral 3mg, 7mg, 14mg tablets |
|---|---|
| BAC Water | N/A — supplied as pre-mixed solution in auto-injector pens |
| Storage | Refrigerate unused pens at 2-8°C; in-use pens may be stored at room temperature up to 30°C for 56 days |
| Shelf Life | 18-24 months unopened; 56 days after first use |
Need exact syringe measurements?
Amino Acid Sequence
His-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys(C18-fatty acid-linker)-Glu-Phe-Ile-Ala-Trp-Leu-Val-Arg-Gly-Arg
Side Effects & Safety
- Nausea (most common, dose-dependent)
- Vomiting and diarrhea
- Constipation
- Decreased appetite
- Risk of pancreatitis (rare)
- Thyroid C-cell tumor risk in animal models (clinical significance uncertain)
- Gallbladder disease
Synergistic Compounds
The following compounds have been studied alongside Semaglutide for potential complementary or synergistic effects:
Learn More
References & Further Reading
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