At a glance
Effects
- Blood sugar control: Stimulates glucose-dependent insulin secretion and suppresses glucagon release, meaningfully reducing HbA1c (by 1.1–1.8% in SUSTAIN trials) without a high intrinsic hypoglycemia risk [3].
- Significant weight loss: In the STEP-1 trial, participants receiving 2.4 mg weekly lost an average of ~14.9% of body weight over 68 weeks compared to ~2.4% with placebo — a result rivalling bariatric surgery outcomes for some patients [6][7].
- Cardiovascular protection: In the SUSTAIN-6 outcome trial, semaglutide reduced major adverse cardiovascular events (MACE: CV death, non-fatal MI, non-fatal stroke) by 26% relative to placebo in adults with T2DM and high CV risk [3].
- Appetite suppression: Centrally activates anorexigenic POMC/CART neurons and inhibits orexigenic NPY/AgRP neurons in the hypothalamic arcuate nucleus, producing sustained reductions in hunger and calorie intake [4].
- Kidney protection: The FLOW trial confirmed that semaglutide 1 mg reduced a composite kidney outcome versus placebo in patients with T2DM and chronic kidney disease [5].
GLP-1 receptor agonist (incretin mimetic)
~7 days (165–184 hrs) — once-weekly dosing
Subcutaneous injection (primary); oral tablet (Rybelsus/Wegovy oral)
Type 2 diabetes, obesity/weight management, CV-risk reduction
4–5 weeks per dose step; ~16–17 wks to maintenance
About Semaglutide
Every point here is drawn from public medical and harm-reduction sources. A bracketed number after a claim — like [1]— is a reference: tap it to open the exact source it's based on (numbered list at the bottom). It is not a rating or score. Educational information, not medical advice.
Product specifics
- Est. delivery
- 3–7 business days · EU tracked
Product details as stated by the vendor (claims, not independently verified). Delivery is our standard EU estimate.
What it is
Semaglutide is a synthetic glucagon-like peptide-1 (GLP-1) receptor agonist — a modified peptide analogue of the natural incretin hormone GLP-1 — FDA-approved for the management of type 2 diabetes (Ozempic), chronic weight management in adults and adolescents with obesity (Wegovy), and reduction of major cardiovascular events in adults with type 2 diabetes and established cardiovascular disease [1][2].
How it works
Semaglutide shares 94% sequence homology with human GLP-1 and selectively binds to GLP-1 receptors throughout the body [1]. In the pancreas, it stimulates insulin secretion in a strictly glucose-dependent manner and suppresses inappropriate glucagon release, lowering blood sugar without causing hypoglycemia on its own [2][3]. In the brain — particularly the hypothalamus and brainstem — it activates appetite-suppressing (anorexigenic) neurons and inhibits hunger-promoting (orexigenic) neurons, reducing food intake [4]. In the gut, it slows gastric emptying, prolonging satiety after meals [5]. Its long ~7-day half-life arises from a fatty-acid modification that promotes albumin binding, reducing renal clearance and protecting the peptide from enzymatic breakdown by DPP-4 [1][3].
Risks & side effects
Most important: Semaglutide carries an FDA Boxed Warning for thyroid C-cell tumours (medullary thyroid carcinoma, or MTC): it is contraindicated in anyone with a personal or family history of MTC or Multiple Endocrine Neoplasia syndrome type 2 [1][2]. Additionally, acute pancreatitis — including fatal haemorrhagic and necrotising cases — has been observed; persistent or severe abdominal pain (sometimes radiating to the back) requires prompt medical evaluation and discontinuation of the drug [2].
Common
- Nausea (most frequent, especially during dose escalation) [8]
- Diarrhoea [8]
- Vomiting [8]
- Constipation [8]
- Abdominal pain and bloating [9]
- Headache and fatigue [9]
- Injection-site reactions (redness, itching) [9]
- Decreased appetite / altered taste (dysgeusia) [9]
- Transient increase in resting heart rate [9]
- A substantial share of the weight lost is lean mass, not fat — trial data put it at roughly a quarter to a third of total weight lost without resistance training and adequate protein.[1]Keep resistance training and protein intake high throughout, and avoid aggressive dose escalation.[1]
Serious
- Acute pancreatitis (including haemorrhagic/necrotising forms) — discontinue if suspected [2]
- Diabetic retinopathy complications — worsening observed in 3.0% vs 1.8% placebo in a 2-year trial; pre-existing eye disease warrants monitoring [10]
- Acute kidney injury — secondary to dehydration from severe GI adverse effects; caution in CKD stage 3b–4 [5]
- Hypoglycaemia — risk elevated when combined with sulfonylureas or insulin; dose reduction of those agents may be required [10]
- Cholelithiasis (gallstones) — increased incidence vs placebo in weight-management trials [8]
- Severe hypersensitivity / anaphylaxis / angioedema — discontinue and seek emergency care [2]
- Pulmonary aspiration risk peri-operatively due to delayed gastric emptying — inform surgeon and anaesthetist [5]
Rare
- Thyroid C-cell tumours / medullary thyroid carcinoma (boxed warning; seen in rodents; human risk unquantified — contraindicated in MTC/MEN-2 history) [1][2]
- Nonarteritic anterior ischaemic optic neuropathy (NAION) — case reports; causal relationship not established [5]
- Supratherapeutic levels of narrow-therapeutic-index drugs (e.g. antipsychotics) due to altered oral drug absorption from gastric emptying delay [5]
- Weight regain upon discontinuation — studies confirm loss of effect reverses after stopping [4]
Safety & harm reduction
- Personal or family history of medullary thyroid carcinoma (MTC) [1][2]
- Multiple Endocrine Neoplasia syndrome type 2 (MEN-2) [1][2]
- Pregnancy — animal data show fetal risk; weight loss not appropriate in pregnancy [6]
- Concurrent use of another GLP-1 receptor agonist or tirzepatide (contraindicated) [6]
- Known serious hypersensitivity to semaglutide or any excipients [2]
- Severe gastroparesis (semaglutide is not recommended) [2]
- Renal function — especially if dehydration occurs from GI side effects, or in CKD stage 3b–4 [5]
- Diabetic retinopathy — baseline and periodic eye exam, particularly in patients with pre-existing retinopathy [10]
- Serum calcitonin or thyroid imaging if a neck lump, hoarseness, or dysphagia develops (possible C-cell change) [2]
- Blood glucose / HbA1c — adjustment of concurrent insulin or sulfonylurea doses may be needed to avoid hypoglycaemia [10]
- Amylase and lipase if abdominal pain occurs (pancreatitis surveillance) [2]
- Heart rate — semaglutide can modestly increase resting heart rate; inform clinician if sustained tachycardia [9]
- Pre-operative gastric content assessment — inform anaesthetist; consider extended fasting or gastric ultrasound before general anaesthesia [5]
- Insulin / sulfonylureas — additive hypoglycaemia risk; reduce their dose when initiating semaglutide [10]
- Oral medications with narrow therapeutic window (e.g. warfarin, certain antiepileptics, antipsychotics) — delayed gastric emptying may alter absorption rate and peak levels [6][5]
- Other GLP-1 agonists / tirzepatide — contraindicated combination [6]
- Metformin — generally well tolerated together; monitor for GI additive effects [5]
- Anti-psychotics — interact on two levels: antipsychotic-associated weight gain counteracts semaglutide benefit, and gastric emptying delay can produce supratherapeutic antipsychotic levels [5]
- Mandatory slow dose escalation: start 0.25 mg/week × 4 weeks, then step up every 4 weeks (0.5 → 1.0 → 1.7 → 2.4 mg for weight management); never skip escalation steps [7]
- Stay well hydrated, especially during periods of nausea, vomiting, or diarrhoea, to protect kidney function [10]
- Rotate injection sites weekly (abdomen, outer thigh, upper arm) to prevent lipohypertrophy [7]
- Eat smaller, lower-fat meals and limit alcohol to reduce GI side effects during escalation [8]
- Disclose semaglutide use to all prescribers and especially to surgeons/anaesthetists before any planned procedure [5]
- Do not stop abruptly without a medical plan — discontinuation leads to weight regain and loss of glycaemic control [4]
Dosage context
These are FDA-approved, clinically established doses — not a prescription. All injectable semaglutide starts at 0.25 mg subcutaneously once weekly (tolerability dose only, not therapeutic) [7]. For weight management (Wegovy injection), the dose escalates every 4 weeks through 0.5 mg → 1.0 mg → 1.7 mg, reaching the 2.4 mg/week maintenance dose by approximately week 17 [7]. For type 2 diabetes (Ozempic injection), the same starting dose applies but maintenance is 0.5–2.0 mg/week maximum [7]. Steady state at each level takes 4–5 weeks [7]. Oral formulations (Rybelsus, Wegovy tablet) follow separate daily escalation schedules with much higher mg doses due to low oral bioavailability [6]. Never self-escalate faster than the approved schedule.
Sources
- 1.FDA Ozempic Prescribing Information (DailyMed)
- 2.Novo Nordisk – Ozempic Mechanism of Action (HCP)
- 3.StatPearls – Semaglutide (NIH Bookshelf)
- 4.PMC – Semaglutide: Double-edged Sword (Risks & Benefits)
- 5.PMC – Semaglutide as a GLP-1 Agonist: Breakthrough in Obesity Treatment
- 6.PMC – Semaglutide in Diabetic Kidney Disease
- 7.Peptide Dosing Protocols – Semaglutide Dosing Guide (FDA-approved titration)
- 8.Fella Health – Semaglutide Mechanism of Action
- 9.Clinical Trial Protocol NCT03987451 – Semaglutide in Fatty Liver (Side Effects)
- 10.Clinical Trial Protocol NCT03819153 – Semaglutide in T2D & CKD (Risk Table)
This information is provided for educational and harm-reduction purposes only. It is not medical advice. These substances can carry serious health risks; effects and safe use vary by individual. Consult a qualified healthcare professional before use. Legal status varies by country — it is your responsibility to know your local law. We do not encourage misuse.
Other options for Semaglutide· 13 offers
Same compound from different labs/brands and pack sizes. Tap a row to switch brand — the price and buy button update instantly.
This compound comes in different forms (e.g. injectable vs oral vs topical). Cost per mg is only comparable within the same form.
| Brand | Form | Strength | Pack | Price | Per mg |
|---|---|---|---|---|---|
Generic | — | — | 33,90 € | — | |
Generic | — | — | 33,90 € | — | |
Generic | — | — | 46,90 € | — | |
Generic | pen | 2 mg | 1 pen | 54,90 € | — |
Intex PharmaSelected | vial | 2 mg | 1 vial | 54,90 € | — |
Generic | — | — | 139,99 € | — | |
Generic | vial | 2 mg | 10 vial | 154,99 € | — |
Generic | — | — | 159,99 € | — | |
Generic | vial | 10 mg | 10 vial | 169,99 € | — |
Generic | — | — | 179,99 € | — | |
Generic | vial | 20 mg | 10 vial | 199,99 € | — |
Generic | — | — | 249,99 € | — | |
Generic | vial | 10 mg | 50 vial | 359,99 € | — |