← Back to codex

Semaglutide

Aliases: Ozempic · Wegovy · Rybelsus

Last verified: 2026-09-23

Approved drugStrong evidencePeptidesHigh interest

The short version

Semaglutidee is the reference point of modern medical science: the STEP program (4,000+ participants) showed ~15% average body weight loss at weekly dosing, with partial persistence at one year. The SUSTAIN program confirmed cardiovascular protection in diabetics (MACE -26%). But it is not a 'vitamin': nausea is very common, pancreatitis and gallbladder complications occur rarely, and muscle mass loss during rapid weight loss is a real problem requiring a strategic approach. This is a drug that requires a physician.

Identity & type

Molecular type
analog
Sequence / structure
31-mer GLP-1 analog, C18 diacid bočni lanac
Molecular weight
~4114 Da
Origin
GLP-1 analog with an extended half-life (~7 days), enabling weekly dosing; basis of Ozempic, Wegovy, Rybelsus.

Mechanism of action

GLP-1R agonist → enhanced glucose-dependent insulin secretion, slowed gastric emptying, central appetite suppression.

Dosing & routes

Official / clinical context

Approved drug — indications, dosing and warnings are defined by the official label. Wegovy: titration to 2.4 mg SC weekly; Ozempic 0.5–2 mg; Rybelsus 3–14 mg orally daily.

Regulator-approved labeling and published study designs — never a recommendation.

Community-reported practice

Wegovy: titration to 2.4 mg SC weekly; Ozempic 0.5–2 mg; Rybelsus 3–14 mg orally daily. Ozempic/Wegovy: pronounced satiety, silenced "food noise", 10–15% weight loss over a year; nausea most common in week one. The community also notes reduced alcohol craving in some users.

Unverified self-reports. Not medical advice. Not endorsement.

Expected effects (community)

Ozempic/Wegovy: pronounced satiety, silenced "food noise", 10–15% weight loss over a year; nausea most common in week one. The community also notes reduced alcohol craving in some users.

Protocol — official vs community

Official / label

Wegovy (obesity): 2.4 mg SC once weekly. Ozempic (T2D): 0.5–2 mg weekly. Rybelsus: 3–14 mg oral daily.

  1. 01Weeks 1–4: 0.25 mg weekly
  2. 02Weeks 5–8: 0.5 mg weekly
  3. 03Weeks 9–12: 1 mg weekly
  4. 04Weeks 13–16: 1.7 mg weekly
  5. 05Week 17+: 2.4 mg maintenance

Duration: Chronic. Discontinuation leads to weight regain in most patients within a year.

Slow titration over ≥16 weeks is what makes the GI side-effect load survivable. Escalate only if the previous step is tolerated.

Community (anecdotal)

Mirrors label titration. Gray-market users typically start at 0.25–0.5 mg weekly regardless of stated vial contents.

Cycle:
Continuous — not cycled.
Break:
None by design; 'GLP-1 holidays' are not evidence-based and regain follows.

Community practice differs from the label mainly in sourcing and in under-dosing during shortages — not in structure.

Human evidence

Among the most robust evidence in medicine: STEP 1–8, SUSTAIN 1–7, SELECT (17,000+ participants, CV prevention in obese non-diabetics).

Preclinical evidence

The preclinical phase was completed and submitted to regulators as part of registration; pharmacology and toxicology details are part of the official label.

Known risks

  • Nausea, vomiting, diarrhea (~40% in first months)characterized
  • Gallstones and rarely pancreatitischaracterized
  • Muscle mass loss with large weight reductioncharacterized
  • Insufficient data in pregnancy; contraindicatedcharacterized

Teal: characterized in clinical/labeling contexts. Amber: theoretical or reported outside controlled settings.

Unknowns & evidence gaps

  • Full duration of use (decades) and rare-event risk
  • Optimal muscle-preservation strategy

Frequently asked questions

References

  1. Wilding J.P.H. et al., STEP 1 (N Engl J Med, 2021)
  2. Marso S.P. et al., SUSTAIN-6 (N Engl J Med, 2016)
  3. Lincoff A.M. et al., SELECT (N Engl J Med, 2023)
  4. Wegovy/Ozempic — FDA labeli