GLP-1 receptor mono-agonist

Semaglutide

CAS: 910463-68-2 MW: ~4,113.6 Da Formula: C₁₈₇H₂₉₁N₄₅O₅₉

1. Identity

FieldValueSource
INNSemaglutide—
Research codesNN9535, NNC0113-0217, OG217SCAcademic secondary source
CAS910463-68-2USP / EP monographs
Molecular formulaC₁₈₇H₂₉₁N₄₅O₅₉Regulatory document — EMA Ozempic EPAR
Molecular weight~4,113.6 DaRegulatory document — EMA Ozempic EPAR
ClassGLP-1 receptor mono-agonist; 31-amino-acid acylated GLP-1 analogue; Aib8 substitution to resist DPP-4 cleavage, Arg34 substitution, Lys26 derivatized with γ-Glu-2×OEG-C18 fatty diacid for albumin bindingRegulatory document — EMA Ozempic EPAR; Peer-reviewed preclinical study — Lau 2015 J Med Chem 58:7370
Half-life~1 week (supports once-weekly subcutaneous dosing)Regulatory document — FDA Ozempic / Wegovy labels
Brand namesOzempic (SC, T2D); Wegovy (SC 2.4 mg, obesity / MASH / CV risk in obesity-with-CVD; SC HD 7.2 mg, obesity); Wegovy oral 25 mg tablets (obesity / CV risk); Rybelsus (oral 3/7/14 mg, T2D)—

2. History and Development

Novo Nordisk developed semaglutide as a long-acting GLP-1 analogue intended for once-weekly subcutaneous dosing, with structural modifications extending half-life to roughly one week [Peer-reviewed human study; Regulatory document — EMA Ozempic EPAR]. 5 December 2017: FDA approves Ozempic for T2D [Regulatory document — FDA NDA 209637]. 8 February 2018: EMA approves Ozempic [Regulatory document — EMA EPAR]. 20 September 2019: FDA approves Rybelsus (oral T2D) [Regulatory document — FDA NDA 213051]. 4 June 2021: FDA approves Wegovy for chronic weight management on the strength of the STEP program [Peer-reviewed human study — Wilding NEJM 2021;384:989] ⚠️. 6 January 2022: EMA approves Wegovy. March 2024: FDA adds CV-risk-reduction indication to Wegovy on the basis of SELECT [Peer-reviewed human study — Lincoff NEJM 2023;389:2221] ⚠️. September 2023: FDA adds ileus to the Ozempic / Wegovy label after FAERS signal [Regulatory document — FDA Drug Safety Communication]. January 2024: FDA preliminary Drug Safety Communication on suicidality finds no evidence of causation [Regulatory document — FDA DSC]. 6 June 2025: EMA PRAC concludes NAION is a “very rare” side effect of semaglutide-containing medicines [Regulatory document — EMA PRAC]; 27 June 2025: WHO global drug alert on NAION. 15 August 2025: FDA approves Wegovy MASH sNDA 215256/s-024 on the strength of ESSENCE Part 1 [Regulatory document — FDA approval letter]. 2025: Ozempic CKD indication added on the strength of FLOW [Peer-reviewed human study — Perkovic NEJM 2024;391:109] ⚠️. 24 November 2025: Novo Nordisk topline release that EVOKE / EVOKE+ failed primary clinical endpoint (CDR-SB) in early symptomatic Alzheimer’s disease [Press release — Novo Nordisk; not peer-reviewed]. 22 December 2025: FDA approves Wegovy pill 25 mg for obesity / CV risk reduction [Regulatory document — FDA approval letter]. 13 January 2026: FDA Drug Safety Communication requesting removal of suicidality warning language across the GLP-1 class after comprehensive meta-analysis and Sentinel review [Regulatory document]. 19 March 2026: FDA accelerated approval of Wegovy HD 7.2 mg on the strength of STEP UP [Peer-reviewed human study — STEP UP, ADA 2025] ⚠️. April / May 2025: FDA enforcement discretion for 503A and 503B compounding of semaglutide ends [Regulatory document — FDA, 2025]. 30 April 2026: FDA proposes to exclude semaglutide, tirzepatide, and liraglutide permanently from the 503B bulks list, with public-comment period through 29 June 2026 [Regulatory document — FDA, Orrick analysis 2026-05].

3. Mechanism of Action

Demonstrated in humans

  • High-affinity agonism at GLP-1R [Peer-reviewed preclinical study — Lau 2015]; in humans this produces glucose-dependent insulin secretion, glucagon suppression, and slowed gastric emptying, with documented tachyphylaxis to the gastric-emptying effect on chronic dosing [Peer-reviewed human study — SUSTAIN/STEP program; FDA Wegovy label] ⚠️
  • Central appetite / satiety reduction via hindbrain (area postrema, nucleus tractus solitarius) GLP-1R and downstream hypothalamic circuits [Peer-reviewed preclinical study — Gabery 2020 JCI Insight; mechanism extrapolated to humans]
  • Body-weight reduction of ~14.9% at 68 wk on SC 2.4 mg [Peer-reviewed human study — Wilding STEP 1] ⚠️; ~20.7% at 72 wk on SC 7.2 mg [STEP UP, ADA 2025] ⚠️; 13.6–16.6% at 64 wk with oral 25 mg [OASIS-4 NEJM 2025] ⚠️
  • HbA1c reduction ~1.0–1.8% in T2D across the SUSTAIN program ⚠️
  • 3-point MACE HR 0.80 in CVD-plus-overweight/obesity without diabetes (SELECT) ⚠️

Proposed / preclinical (status: preclinical or pending replication)

  • Anti-inflammatory and neuroinflammatory modulation — biomarker shifts in the EVOKE program but no clinical translation; primary clinical endpoint not met [Peer-reviewed human study — Scheltens 2026; Cummings/Atri Lancet 2026] ⚠️
  • Reduction of alcohol / nicotine intake — rodent pharmacology and two small positive randomized Phase 2 trials; mechanism remains hypothesis-generating [Peer-reviewed preclinical study — Jerlhag group; Peer-reviewed human study — Hendershot JAMA Psychiatry 2025;82:395-405; Klausen SEMALCO Lancet 2026]
  • Direct cardio-renal mechanisms beyond weight loss — preclinical; SELECT and FLOW mediation analyses ongoing [Peer-reviewed human study — Lincoff 2023; Perkovic 2024] ⚠️
  • Neuroprotection beyond AD — preclinical only.

4. Regulatory Status

  • FDA: Approved — Ozempic (T2D 2017; CV risk reduction in T2D 2020; CKD in T2D 2025); Wegovy SC (obesity 2021; CV risk reduction in CVD-plus-obesity/overweight March 2024; MASH August 2025); Wegovy HD 7.2 mg (obesity, accelerated approval 19 March 2026); Wegovy oral 25 mg (obesity / CV risk reduction, 22 December 2025); Rybelsus (T2D 2019; CV risk reduction in T2D added 2025) [Regulatory document]
  • EMA: Ozempic 8 February 2018; Rybelsus 3 April 2020; Wegovy 6 January 2022; multiple subsequent variations including PRAC NAION conclusion June 2025 [Regulatory document — EMA EPAR pages]
  • MHRA: Approved (post-Brexit reliance on EMA; Wegovy available through NHS pathways) [Regulatory document]
  • PMDA (Japan): Approved as Ozempic and Rybelsus; SUSTAIN-J / PIONEER-J trials [Regulatory document]
  • NMPA (China): Approved — Ozempic, Rybelsus, Wegovy [Regulatory document]
  • MFDS (Korea), TGA (Australia), Health Canada: Approved across T2D and weight management; CV indications where labelled [Regulatory document]
  • GRLS (Russia): Registered as Оземпик, Ребелсас, Веговы [Regulatory document — grls.rosminzdrav.ru; machine-translation caveat]
  • WHO EML: Not on the core list as of the 2023–2025 cycle
  • WADA 2026: On the Monitoring Program, not on the Prohibited List [Regulatory document — WADA 2026]

5. Formulations and Routes

Approved:

  • SC weekly: Ozempic 0.25 / 0.5 / 1.0 / 2.0 mg; Wegovy 0.25 / 0.5 / 1.0 / 1.7 / 2.4 mg; Wegovy HD 7.2 mg [Regulatory document]
  • Oral daily: Rybelsus 3 / 7 / 14 mg (T2D); Wegovy oral 25 mg (obesity / CV risk reduction). Oral formulation co-administered with SNAC absorption enhancer; oral bioavailability ~0.4–1% [Peer-reviewed human study]
  • Pediatric: Standard SC pen for STEP TEENS population (≥12 yr) [Regulatory document]

Investigational / non-approved:

  • SC daily 0.4 mg — studied only in the Phase 2 MASH trial [Peer-reviewed human study — Newsome 2021 NEJM 384:1113]; not approved for chronic use
  • Intramuscular, intranasal, transdermal: Not supported by medical literature for any route other than SC and oral
  • Compounded products: With shortage resolved February 2025 and enforcement-discretion periods ending April / May 2025, large-scale compounding is no longer permissible under FDA guidance [Regulatory document — FDA, 2025; Orrick 2026-05]. FDA proposed permanent exclusion of semaglutide from 503B bulks list on 30 April 2026

Approved combinations: CagriSema (semaglutide + cagrilintide) under FDA review on the strength of REDEFINE 1 and REDEFINE 2 [Peer-reviewed human study — Garvey NEJM 2025;393:635; Davies NEJM 2025;393:648]; no marketing authorization as of 13 May 2026.

6. Preclinical Evidence

Status label: Preclinical evidence exists; human clinical trials completed and approved drug status achieved across multiple indications.

  • In vitro: GLP-1R EC50 ~0.38 nM; albumin K_d in low-µM range [Peer-reviewed preclinical study]
  • Rodent T2D / DIO models: Dose-dependent reductions in fasting glucose, HbA1c-equivalent, body weight, hepatic steatosis [Peer-reviewed preclinical study]
  • Carcinogenicity: Two-year rodent studies show dose- and duration-dependent thyroid C-cell tumours in rats — basis of the US boxed warning; human relevance undetermined [Regulatory document — FDA label / EMA EPAR]
  • Reproductive toxicology: Embryo-fetal toxicity in rats, rabbits, cynomolgus monkeys at clinically relevant exposures [Regulatory document]
  • Cardiovascular safety pharmacology: Modest heart-rate increases in primates, paralleled in human trials [Regulatory document]

7. Clinical Evidence

Overview. Most extensively trialed GLP-1 RA. Approved-drug status; Strong Clinical Evidence (Level 1a) for T2D and obesity. Pivotal trials by indication:

T2D

  • SUSTAIN 1–10, including SUSTAIN-6 CVOT: MACE HR 0.74 (p<0.001 non-inferiority, post-hoc superiority); HbA1c −1.3 to −1.8%, weight loss 4–6 kg [Peer-reviewed human study — Marso NEJM 2016] ⚠️
  • PIONEER 1–10, including PIONEER-6 CVOT: Oral semaglutide HbA1c −1.0 to −1.4%; PIONEER-6 MACE non-inferior to placebo [Peer-reviewed human study — Husain NEJM 2019] ⚠️
  • SOUL: Oral semaglutide in T2D + ASCVD/CKD (n=9,650); 3-point MACE HR 0.86 (p=0.006), ~14% reduction over median 47.5 months [Peer-reviewed human study — McGuire NEJM 2025;392:2001] ⚠️

Obesity

  • STEP 1: Mean weight loss −14.9% vs −2.4% placebo at 68 wk in non-diabetic obese (n=1,961) [Peer-reviewed human study — Wilding NEJM 2021] ⚠️
  • STEP 2 (obesity + T2D), 3 (intensive behavioural therapy), 4 (withdrawal), 5 (2-yr), TEENS (12–17 yr, BMI −16.7 pp), 8 (vs liraglutide): All positive [Peer-reviewed human studies] ⚠️
  • STEP UP (Wegovy HD 7.2 mg vs 2.4 mg vs placebo, n=1,407): −20.7% vs −17.5% vs −2.4% at 72 wk; dysesthesia 22.9% / 6.0% / 0.5% [Peer-reviewed human study — STEP UP, ADA 2025] ⚠️
  • OASIS-4 (oral 25 mg, n=307): −13.6% (treatment-policy) / −16.6% (trial-product) vs −2.4% at 64 wk [Peer-reviewed human study — Wharton NEJM 2025] ⚠️
  • SURMOUNT-5 (semaglutide 2.4 mg vs tirzepatide max-tolerated, open-label, n=751): −13.7% vs −20.2% at 72 wk (p<0.001); semaglutide inferior on all primary and secondary endpoints; Lilly-funded — loss noted, presented without resolution [Peer-reviewed human study — Aronne NEJM 2025] ⚠️

Cardiovascular / renal / metabolic

  • SELECT (CVD + overweight/obesity, no DM, n=17,604): 3-point MACE HR 0.80 (p<0.001), ~20% RRR; 4-yr weight loss −10.2% [Peer-reviewed human study — Lincoff NEJM 2023] ⚠️
  • FLOW (T2D + CKD, n=3,533): composite kidney-and-CV outcome HR 0.76 over 3.4 yr; stopped early for efficacy [Peer-reviewed human study — Perkovic NEJM 2024] ⚠️
  • STRIDE (T2D + PAD, n=792, SC 1.0 mg): maximum walking distance ETR 1.13 (p=0.0004) at 52 wk; pain-free walking distance and QoL also superior [Peer-reviewed human study — Bonaca Lancet 2025] ⚠️

MASH

  • ESSENCE Part 1 (MASH F2–F3, interim n=800 of 1,197): MASH resolution without worsening fibrosis 62.9% vs 34.3% (Δ 28.7 pp; p<0.001) at 72 wk; fibrosis improvement without worsening MASH 36.8% vs 22.4%. Part 2 cirrhotic-outcome readout 2029 [Peer-reviewed human study — Sanyal & Newsome NEJM 2025;392:2089] ⚠️

Neurodegeneration — failed

  • EVOKE / EVOKE+ (oral semaglutide 14 mg in early symptomatic AD, amyloid+; n≈3,800): did NOT meet primary clinical endpoint (CDR-SB). Biomarkers improved. Full Lancet 2026 publication; pathway largely closed for clinical AD slowing [Peer-reviewed human study — Cummings/Atri Lancet 2026; Press release — Novo Nordisk 24 Nov 2025] ⚠️

Substance use disorder

  • Hendershot et al. (UNC; n=48, low-dose SC): Reduced lab alcohol self-administration (β −0.48), reduced weekly craving, reduced cigarettes/day in smoker subgroup [Peer-reviewed human study — JAMA Psychiatry 2025;82:395]
  • SEMALCO (Klausen, Copenhagen; n=108, 26 wk, semaglutide 2.4 mg + CBT): heavy drinking days −41.1 pp vs −26.4 pp placebo; ETD −13.7 pp (p=0.0015) [Peer-reviewed human study — Lancet 2026]
  • TriNetX observational signals: ~50–56% reduced AUD incidence and recurrence vs other anti-obesity comparators [Peer-reviewed human study — Wang Nat Commun 2024] 🔴 (largely single-group)

Cochrane status. No semaglutide-specific Cochrane SR as of 13 May 2026 [verified — Cochrane Library]. Multiple peer-reviewed meta-analyses supportive across approved indications.

Retraction check. No retractions identified for cited primary trials as of 13 May 2026.

7B. Community Evidence Layer

Summary (full detail in semaglutide_com_2026-05-13_C92.md).

Adoption. Earliest documented optimization-audience clinical use: Peter Attia, fall 2020 (The Drive AMA #45, peterattiamd.com/ama45, 2023-03 — “I have a great deal of clinical experience with semaglutide. I’ve been using it now in patients for about two-and-a-half years”). Mass-cultural moment: 2022 “TikTok Ozempic” wave (APA Online, blog.apaonline.org/2024/06/12, “food noise” tagged TikTok videos passed 1.8 billion views by mid-2023). The community-coined term “food noise” originated in patient discourse on r/WegovyWeightLoss and r/Semaglutide before any pharma adoption.

Subcommunities, May 2026: medical-adopter weight loss (largest; broader than the entire tirzepatide community combined); compounded-telehealth consumer (contracting after Hims’s 9 March 2026 brand-only pivot); women’s weight-loss (r/WegovyWeightLoss); bodybuilding-cut (research-chem channel, r/Peptides); microdose-for-longevity (Bryan-Johnson-adjacent, 0.125–0.25 mg/week); addiction-craving (post-UNC AUD trial); diabetic self-managed; nootropic-adjacent (“brain fog” / Alzheimer’s prevention — note: now contradicted by EVOKE).

Protocols, codified at three levels:

  • Standard label (Wegovy 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg weekly q4w; Ozempic 0.25 → 0.5 → 1.0 → 2.0 mg)
  • Microdose subculture (0.125 or 0.25 mg/week, indefinite — Bryan Johnson protocol.bryanjohnson.com, 2025; Stanfield drstanfield.com, 2025, skeptic)
  • Aggressive cut bodybuilding (rapid escalation to 2.0+ mg, 12–16 wk cycles, r/Peptides channel-level)

Top claimed effects. “Food noise” reduction (widespread; Novo + Market Track 550-person EASD 2024 survey, scitechdaily.com 2024). Appetite suppression within 24–72 h of first 0.25 mg dose (widespread). Weight loss ~15% as community expectation, anchored on STEP 1 (widespread). CV event-rate reduction (common, post-SELECT). Alcohol craving reduction (common; UNC press release news.unchealthcare.org, 2025-02). Nicotine craving reduction (occasional). Compulsive-behavior reduction including gambling and shopping (occasional, anecdotal). Depression / anxiety improvement (common, post-April 2026 Lancet observational coverage in Boston Globe 2026-04). Alzheimer’s risk reduction (occasional — note: science layer now negative on EVOKE).

Top reported side effects. GI (widespread, dose-dependent). “Sulfur burps” (common, community-specific term). “Ozempic personality” / anhedonia / mood flattening (emerging widespread cluster, Washington Post 2026-04-16, KTLA, NZ Herald, Boston Globe; Novo response: “anhedonia is not currently listed as an adverse drug reaction or warning”). Muscle loss / sarcopenia anxiety (widespread, Attia AMA #45 2023-03, Layne Norton biolayne.com Ep. 18). Hair shedding 3–6 months in (common). “Ozempic face” / skin elasticity loss (common, predominantly negative). Compounded-product–specific complaints — underdosing (68–122% of label per gitelcare.com 2025), painful injection, particulate (common in compounded channels). Rebound weight gain on discontinuation (widespread fear cluster; Attia AMAs #45 and #64). NAION community awareness (occasional, propagated via Eric-Topol-adjacent newsletters and JAMA Ophthalmol coverage).

Dissent. Anti-GLP-1 metabolic-health wing (Mark Hyman drhyman.com eps. 848/884/992; Casey & Calley Means) framing as symptom-not-cause. Bodybuilding sarcopenia critique (Norton biolayne.com Ep. 18; Attia AMA #45). “You’re on it for life” pragmatists vs. cycling camp (irreconcilable). Microdose-advocate (Bryan Johnson) vs microdose-skeptic (Brad Stanfield: “For my patients who aren’t overweight or aren’t managing diabetes, I don’t recommend microdosing GLP-1s”). Tirzepatide-superiority advocates vs semaglutide-pragmatists (longer real-world data, SELECT CV indication that tirz lacks, NovoCare $349 self-pay floor). Compounded-pharmacy trust crisis (Empower fourth FDA warning letter April 2025; Mochi / Aequita Washington State action February 2026 per KING 5; FDA >455 adverse-event reports for compounded semaglutide).

Vendor / supply, May 2026. Brand channel via NovoCare: list $1,349/pkg; self-pay $349/month standard (down from $499); $199 introductory two-month price through 31 March 2026; Wegovy pill $149/month savings card through August 2026 (novocare.com, accessed 2026-05). Compounded-telehealth channel contracting: Hims discontinued compounded GLP-1s 9 March 2026 and migrated patients to brand Wegovy / Ozempic / Zepbound / Mounjaro (healthymealsincentives.org/hims-reviews, 2026-04); Mochi Health, Henry Meds still dispensing as of April 2026 under active litigation. Research-chemical peptide channel rising as spillover destination; community-signal price range $40–90 per 5 mg vial, $80–160 per 10 mg vial (channel-level only; vendor pages not opened in Pass 2).

Community Score: 92 / 100 (Usage 25/25; Codification 24/25; Effect consistency 22/25; Time-in-circulation 21/25). Highest community score in the catalog to date — higher than tirzepatide (C81) on usage volume and time in circulation, equal on protocol codification.

8. Safety Profile

Boxed warning (US). Thyroid C-cell tumours (rodent carcinogenicity, MTC / MEN-2 contraindication); human relevance undetermined [Regulatory document].

Common AEs (>10%). Nausea (15–44%), vomiting (5–24%), diarrhea (8–30%), constipation (6–24%), abdominal pain, decreased appetite. Dose-titration related; mostly transient [Peer-reviewed human study — STEP / SUSTAIN / PIONEER programs; FDA labels] ⚠️.

Serious / labelled.

  • Pancreatitis — causality unsettled; numerical signal in some trials but not in SELECT or FLOW [Lincoff 2023; Perkovic 2024] ⚠️
  • Gallbladder disease / cholelithiasis — dose- and weight-loss-related [Regulatory document]
  • Ileus — added to US label September 2023 following FAERS signal [Regulatory document — FDA]
  • Diabetic retinopathy worsening — SUSTAIN-6 signal in T2D with pre-existing retinopathy and rapid glycaemic improvement [Marso 2016]
  • NAION — EMA PRAC “very rare” (up to 1 in 10,000) on 6 June 2025; multicentre OHDSI study (Cai JAMA Ophthalmol 2024–25) plus Danish-Norwegian cohort and US Veterans target-trial emulation reported ~2-fold relative risk vs comparators; absolute incidence remains low. EU product information updated; WHO global alert 27 June 2025; FDA review ongoing [Regulatory document — EMA PRAC 2025; WHO]
  • Suicidality — FDA preliminary DSC January 2024 found no evidence of causation; comprehensive meta-analysis and Sentinel review confirmed no causal association in 2025; FDA requested removal of warning language 13 January 2026 [Regulatory document — FDA DSC]. Conflicting FAERS disproportionality persists in observational literature [Schoretsanitis JAMA Netw Open 2024] — both perspectives presented without resolution
  • Aspiration during anesthesia — secondary to delayed gastric emptying; ASA / multispecialty 2023–2024 perioperative guidance [Regulatory document]
  • Dysesthesia at 7.2 mg — newly elevated incidence in STEP UP (22.9% on 7.2 mg vs 6.0% on 2.4 mg vs 0.5% placebo); FDA continues to investigate [Regulatory document — FDA Wegovy HD review] ⚠️

Special populations.

  • Pregnancy: Animal embryo-fetal toxicity at clinically relevant exposures; “may cause fetal harm” — discontinue ≥2 months before planned conception due to long half-life [Regulatory document]
  • Lactation: No human data; not recommended
  • Pediatric: Approved ≥12 yr for chronic weight management (STEP TEENS)
  • Elderly: No dose adjustment
  • Renal impairment: No adjustment up to ESRD; FLOW supports use in advanced CKD
  • Hepatic impairment: No clinically significant PK effect; ESSENCE supports MASH use

Compounded-product adverse events. FDA logged >455 adverse-event reports for compounded semaglutide through 2025; combined with compounded tirzepatide (>320), >1,150 combined reports and ~10 deaths potentially associated with compounded GLP-1 RAs across the class [Pharmacy Times 2025; gitelcare.com 2025; healthymealsincentives.org 2026-04].

Retraction status. No retractions identified for cited primary trials as of 13 May 2026.

Community-reported AEs requiring science-layer attention. The “Ozempic personality” / anhedonia / mood-flattening cluster (Washington Post, Boston Globe, KTLA, NZ Herald, April 2026) is not currently a labeled or pharma-acknowledged adverse drug reaction. Novo (via Liz Skrbkova in Washington Post, 2026-04-16): “anhedonia is not currently listed as an adverse drug reaction or warning.” A University of Florida researcher cited in Boston Globe describes “chronically muted” reward responses in rat models. The mismatch between the community claim and the regulatory record is real and named.

9. Drug Interactions

  • Delayed gastric emptying may alter rate (not extent) of absorption of co-administered oral drugs; clinical significance generally low except for narrow-therapeutic-index drugs (levothyroxine, oral contraceptives, anticonvulsants, warfarin INR monitoring) [Regulatory document — FDA labels]
  • Co-administration with insulin or sulfonylureas increases hypoglycemia risk; dose reduction recommended [Regulatory document]
  • Oral semaglutide (Rybelsus and Wegovy pill): take in fasted state with ≤120 mL water; wait ≥30 min before food, drink, or other oral medication (SNAC absorption window) [Regulatory document — FDA Rybelsus / Wegovy pill labels]
  • No clinically significant CYP-mediated interactions identified [Regulatory document — FDA Clinical Pharmacology reviews]

10. Research Gaps

  1. No Cochrane SR specific to semaglutide as of 13 May 2026 [verified — Cochrane Library]
  2. No head-to-head Phase 3 vs retatrutide. TRIUMPH program ongoing (Lilly); SURMOUNT-5 has already placed semaglutide behind tirzepatide on weight magnitude
  3. Pediatric obesity <12 yr — no pivotal trials
  4. Long-term outcomes >5 yr in non-diabetic obese — only SELECT (~3.3 yr mean) and OASIS-4 (limited follow-up)
  5. Sustained efficacy after discontinuation — STEP 4 shows substantial regain after withdrawal; no maintenance-formulation pivotal trial
  6. Pregnancy registry readouts — pending
  7. Real-world durability in LMIC settings
  8. CV benefit mediation beyond weight loss — SELECT subgroup mediation analyses ongoing
  9. Alzheimer’s — EVOKE / EVOKE+ failed primary endpoint; pathway largely closed for clinical AD slowing
  10. Aesthetic / cosmetic use (BMI <27) — no dedicated trial data; not approved use
  11. Anti-aging / longevity endpoint trial — none registered
  12. “Ozempic personality” / anhedonia — emerging community cluster with no pharma characterization; rodent reward-circuit data exist but no human prospective trial
  13. Microdose efficacy and safety at 0.125–0.25 mg/wk — no controlled human data despite an entire community subculture
  14. Compounded vs brand pharmacovigilance — >455 FDA reports for compounded semaglutide; no formal head-to-head safety study
  15. STAR trial primary publication pending [NCT04707768]
  16. Exact 2025–2026 FAERS counts for compounded semaglutide adverse events not summarised in a single regulatory communication

11. Bottom-Line Encyclopedia Note (≤150 words)

Semaglutide (Ozempic, Wegovy SC 2.4 mg and HD 7.2 mg, Rybelsus oral, Wegovy oral 25 mg) is the most extensively studied GLP-1 receptor mono-agonist. Phase 3 evidence supports glycemic control in T2D, 14–21% mean body-weight reduction in obesity, 20% MACE reduction in obesity without diabetes (SELECT), 24% kidney-event reduction in T2D-CKD (FLOW), 14% MACE reduction with oral in high-risk T2D (SOUL), improved walking in PAD (STRIDE), and histological improvement in MASH F2–F3 (ESSENCE Part 1). Pharmacovigilance has formally added NAION (very rare). SURMOUNT-5 places semaglutide behind tirzepatide for weight loss. EVOKE / EVOKE+ failed in Alzheimer’s. Community footprint is the deepest in the catalog (~6 years dense optimization-audience signal); off-label microdose, BMI <27 aesthetic, longevity, and “Ozempic personality” claims sit largely outside the trial evidence. WADA 2026: Monitoring Program, not Prohibited.

11B. Gap Analysis (killer feature)

Pattern cell for the primary optimization indication (obesity): High community + High science — Convergent. Few catalog compounds occupy this cell as fully as semaglutide. Most claim-by-claim cells are aligned. The interesting work is in the off-axis indications and the novel community claims that the science has not yet characterized.

Claim / signalScience layer (Pass 1)Community layer (Pass 2)Gap and broker note
Weight loss ~14–21% in obesitySTEP 1, STEP UP, OASIS-4 — replicated”~15%” treated as expectation, anchored on STEP 1 (widespread)Convergent. Community quotes Phase 3 figures accurately; no extrapolation.
CV event reduction (SELECT)HR 0.80 in CVD + overweight/obesity, no DM”~20% MACE reduction” widely cited as community talking pointConvergent.
MASH (ESSENCE)F2–F3 MASH resolution 62.9% vs 34.3% at 72 wkLargely absent from optimization-community discourseLow community + High science — therapeutic-only indication; audience disconnect.
CKD in T2D (FLOW)HR 0.76 kidney compositeOccasional, referenced in WellnessPulse-style longevity coverageLow community + High science — therapeutic-only audience disconnect.
”Food noise” reductionPhenomenon identified in trials and surveys (Novo + Market Track EASD 2024)Community-coined term that pharma adopted from patients (r/WegovyWeightLoss → TikTok → industry)Convergent, with reverse-direction transfer. Rare case where community vocabulary preceded the scientific construct.
Alcohol craving reductionTwo Phase 2 RCTs (UNC Hendershot 2025; SEMALCO Klausen 2026) + TriNetX observationalCommon community claim, predates the trials by ~3 yearsCommunity ahead of science, now catching up. Tier C/30 in science layer; community claim is broader than the trial population. Subclassify: tested-positive-preliminary.
Compulsive-behavior reduction (gambling, shopping, nicotine)UNC trial: cigarettes/day reduced in smoker subgroup; gambling/shopping uncharacterizedOccasional community claim across all threeCommunity ahead of science. Mechanism-plausible (GLP-1R in reward circuits) but only the nicotine subgroup is trial-supported. Subclassify: untested for gambling/shopping; tested-preliminary for nicotine.
Alzheimer’s / dementia risk reductionEVOKE / EVOKE+ failed primary endpoint November 2025Occasional community claim, citing pre-EVOKE observational signals (Wang J Alz Dis 2025)🔴 MAJOR GAP — community claim continues to circulate based on observational data that the pivotal Phase 3 program now contradicts. Time-lag absorption gap. Most community sources have not updated since November 2025 topline.
”Ozempic personality” / anhedonia / mood flatteningNot a labeled ADR; Novo: “not currently listed as an adverse drug reaction or warning”; UF rodent reward-circuit data existEmerging widespread cluster, April 2026 Washington Post / Boston Globe / KTLA / NZ Herald🔴 MAJOR GAP — community claim outruns the labeled safety record. Subclassify: tested-mixed at the rodent / observational level, untested at the prospective-human-trial level.
NAION / vision changesEMA PRAC “very rare” June 2025; OHDSI study + Danish-Norwegian / US Veterans target-trial emulation ~2-fold RROccasional, community-aware via Topol newsletter, JAMA Ophthalmol coverageConvergent at the existence level; magnitude often understated in community discourse. Real signal; absolute incidence low.
”Ozempic face” / skin elasticityNot a labeled effect; consistent with rapid weight loss in any modalityCommon, predominantly negative clusterConvergent on the fact (skin redistributes with fat loss); community framing isolates it to GLP-1 when it is weight-loss-class effect.
Muscle loss / sarcopeniaDEXA sub-studies in STEP showed proportional lean-mass loss within expected range for the magnitude of weight lossWidespread anxiety; anchor: Attia AMA #45 2023-03; Norton Ep. 18Convergent on the fact. Community concern correctly identifies a class-level issue; lifestyle stack (≥1.6 g/kg protein, resistance training) is the codified mitigation in both layers.
Rebound weight gain on discontinuationSTEP 4 — substantial regain after withdrawalWidespread fear cluster (“you’re on it for life”)Convergent on the fact. Both layers blind on what reliably mitigates it.
Compounded vs brand pharmacovigilance>455 FDA reports for compounded semaglutide; 68–122% potency assays per GitelCare; Empower fourth FDA warning letter April 2025; FDA proposed 503B bulks-list exclusion 30 April 2026Split between “compounded was always sketchy” and “personalized 503A is equivalent”Science has hard data the community contests. Compounded ≠ brand on the FDA record.
Microdose (0.125–0.25 mg/wk) for longevity / metabolic flexibilityNo human trial at these dosesDistinct community subculture; advocates (Bryan Johnson) vs skeptics (Brad Stanfield)🔴 MAJOR GAP — entire subculture runs at a dose level with no controlled human evidence. Subclassify: untested. Both Stanfield and Attia explicitly recommend against in non-obese.
Aesthetic use in BMI <27Tier D/5; no pivotal trial in this populationRising off-label community usage; telehealth-channel demand🔴 MAJOR GAP — community has built an entire indication outside the trial evidence base. Subclassify: untested. Risk profile in lean individuals not characterized (sarcopenia, GI, NAION, possible muscle/bone loss).
Anti-aging / longevityTier E/0; no longevity-endpoint RCTOccasional, Bryan-Johnson-anchored framing🔴 MAJOR GAP. Subclassify: untested. CV/CKD/mortality benefits demonstrated in disease populations only; no evidence in healthy non-obese adults at any dose.
WADA statusMonitoring Program, not ProhibitedMostly unawareAudience disconnect. Negligible for non-competing users; matters for tested athletes.
SuicidalityFDA / EMA / Sentinel reviews 2024–2026 — no causal association; FDA removal-of-warning request January 2026Persistent community concern, kept alive by Hyman et al. quoting EU reviewTested-negative at the pharmacovigilance level; the community concern lags the regulatory update.
Independent clinical replicationMulti-region SUSTAIN-J, PIONEER-J, regional analogues; RCT-DUPLICATE replicationCommunity treats Novo data as sufficientConvergent — semaglutide is one of the few catalog compounds with genuinely robust independent replication.

Net characterisation. Semaglutide sits in the convergent quadrant for its two labeled flagship indications (T2D and obesity), with the community having largely arrived at and accurately repeated the trial findings. The most consequential gaps are concentrated in four off-axis areas:

  1. Microdose subculture (0.125–0.25 mg/wk) runs in a dose space with no human trial evidence, and named-figure dissent (Stanfield, Attia) is on the skeptic side.
  2. Aesthetic use in BMI <27 is an unindexed off-label market the trial program has not characterized.
  3. “Ozempic personality” / anhedonia is a real and growing community signal that the pharmacovigilance system has not yet acknowledged as a labeled ADR.
  4. The community’s residual Alzheimer’s-prevention claim now contradicts the EVOKE Phase 3 readout by approximately six months and has not been retracted in most community sources.

12. Three Paths

You choose your risk tolerance. This monograph provides the data, not the recommendation.

Conservative path — prescription, on-label. Defined as: semaglutide for a labeled indication (T2D, obesity BMI ≥30 or BMI ≥27 + weight-related comorbidity, CV risk reduction in CVD + overweight/obesity, MASH F2–F3, CKD in T2D) via brand product (Ozempic, Wegovy SC, Wegovy HD, Wegovy oral 25 mg, or Rybelsus), prescribed and titrated by a physician, with the labeled monitoring cadence and the labeled escalation schedule. Standard pre-treatment workup: HbA1c, lipid panel, ALT / AST / GGT, lipase, basic metabolic panel, TSH, MTC family-history screening, baseline retinal exam for T2D patients with retinopathy; on-treatment review at each escalation, then quarterly to annually depending on indication. All four conservative gates — peer-reviewed Phase 3 publication ✓, regulatory approval in ≥1 major jurisdiction ✓, independent clinical replication ✓ (multi-region SUSTAIN-J / PIONEER-J / multiple RWE), long-term outcomes ✓ (SELECT 3.3 yr mean; FLOW 3.4 yr median; ESSENCE Part 2 cirrhotic-outcome readout 2029) — are met for T2D, obesity, CV, MASH, and CKD-in-T2D. Semaglutide is the rare catalog compound where the conservative path is fully available across multiple indications.

Moderate path — prescription with off-label flexibility. Defined as: prescribed and supervised semaglutide extended beyond the strict label envelope — for example, BMI 25–27 without a strictly defined weight-related comorbidity but with elevated cardiometabolic risk; metabolic-syndrome reversal as a primary goal rather than weight per se; or use of personalized 503A formulations where they remain legally available (note: the regulatory window for this is closing). This path means: full pre-cycle bloodwork (as conservative, plus DXA or BIA baseline, resting HR / BP, and a baseline ophthalmologic exam given the NAION signal); on-cycle bloodwork every 8–12 weeks; lifestyle co-administration of protein at the upper community-standard range (≥1.6 g/kg, common community target ≥1 g/lb of target body weight) and structured resistance training; awareness of the contraception window after each escalation (≥2 months before planned conception); explicit awareness of the EVOKE failure (drop any Alzheimer’s-prevention rationale); explicit awareness of the “Ozempic personality” community signal as currently un-labeled; awareness that compounded ≠ brand on the FDA adverse-event record. The conservative path is preferable where the patient meets a labeled indication; the moderate path begins where labeled indications end.

High-tolerance path — grey-market with mitigation. Defined as: research-peptide channel access acknowledging that (a) the product is not regulated for human use, (b) batch identity and potency are not guaranteed (independent assays have shown 68–122% of label per GitelCare 2025), (c) the FDA has logged >455 adverse-event reports linked to compounded semaglutide, (d) the community-recommended dose for aesthetic use (typically the full Wegovy 2.4 mg or higher) is outside the trial evidence for BMI <27, and (e) microdose protocols below the 0.25 mg labeled starting dose have zero controlled human evidence. The community mitigation stack documented here: third-party COA verification (Janoshik or MZ Biolabs) of the specific vial; baseline and on-cycle bloodwork on the optimization-community schedule (CBC, CMP, lipids, HbA1c, lipase, TSH, every 8–12 weeks); resting HR / BP tracking; baseline retinal exam given NAION; pre-cycle dialogue with a physician willing to continue monitoring even where they have not prescribed; deliberate awareness that “Ozempic personality,” rebound on discontinuation, and the long-term sarcopenia profile in lean users are open questions. The high-tolerance path is the dominant channel for BMI <27 aesthetic use and for microdose-for-longevity protocols, both of which sit outside the trial evidence base entirely.

13. Key References

Scientific:

  • Lau J et al. J Med Chem 2015;58:7370 — discovery and design [Peer-reviewed preclinical]
  • Marso SP et al. SUSTAIN-6, NEJM 2016;375:1834, PMID 27633186 [Peer-reviewed human study] ⚠️
  • Husain M et al. PIONEER-6, NEJM 2019;381:841 [Peer-reviewed human study] ⚠️
  • Wilding JPH et al. STEP 1, NEJM 2021;384:989 [Peer-reviewed human study] ⚠️
  • Newsome PN et al. Phase 2 NASH, NEJM 2021;384:1113 [Peer-reviewed human study] ⚠️
  • Weghuber D et al. STEP TEENS, NEJM 2022;387:2245 [Peer-reviewed human study] ⚠️
  • Lincoff AM et al. SELECT, NEJM 2023;389:2221, DOI 10.1056/NEJMoa2307563 [Peer-reviewed human study] ⚠️
  • Kosiborod MN et al. STEP-HFpEF, NEJM 2023;389:1069; STEP-HFpEF DM NEJM 2024 [Peer-reviewed human study] ⚠️
  • Perkovic V et al. FLOW, NEJM 2024;391:109, PMID 38785209 [Peer-reviewed human study] ⚠️
  • McGuire DK et al. SOUL, NEJM 2025;392:2001, PMID 40162642 [Peer-reviewed human study] ⚠️
  • Sanyal AJ, Newsome PN et al. ESSENCE Part 1, NEJM 2025;392:2089, DOI 10.1056/NEJMoa2413258 [Peer-reviewed human study] ⚠️
  • Bonaca MP et al. STRIDE, Lancet 2025, DOI 10.1016/S0140-6736(25)00509-4 [Peer-reviewed human study] ⚠️
  • Wharton S et al. OASIS-4, NEJM 2025 [Peer-reviewed human study] ⚠️
  • Aronne LJ et al. SURMOUNT-5, NEJM 2025 [Peer-reviewed human study] (Lilly-funded) ⚠️
  • Cummings JL, Atri A et al. EVOKE / EVOKE+, Lancet 2026, DOI 10.1016/S0140-6736(26)00459-9 [Peer-reviewed human study] ⚠️ — negative primary endpoint
  • Hendershot CS et al. JAMA Psychiatry 2025;82:395-405 [Peer-reviewed human study]
  • Klausen MK et al. SEMALCO, Lancet 2026, DOI 10.1016/S0140-6736(26)00305-3 [Peer-reviewed human study]
  • Cai CX et al. NAION OHDSI study, JAMA Ophthalmol 2025 [Peer-reviewed human study]
  • Wang W et al. Semaglutide and AUD, Nat Commun 2024;15:4548 [Peer-reviewed human study] 🔴
  • Schoretsanitis G et al. Suicidality FAERS, JAMA Netw Open 2024;7:e2423385 [Peer-reviewed human study]
  • FDA Drug Safety Communications: ileus addition Sep 2023; GLP-1 RA suicidality preliminary Jan 2024; suicidality removal request 13 Jan 2026; Wegovy HD 7.2 mg approval 19 Mar 2026; Wegovy pill 25 mg approval 22 Dec 2025; Wegovy MASH s-024 approval 15 Aug 2025 [Regulatory document]
  • EMA PRAC Highlights 2–5 June 2025 — NAION; WHO Drug Alert 27 June 2025 [Regulatory document]
  • WADA 2026 Prohibited List and Monitoring Program [Regulatory document]

Community:

  • Peter Attia The Drive AMA #29 (peterattiamd.com/ama29, 2021-11), AMA #45 (peterattiamd.com/ama45, 2023-03), AMA #64 (peterattiamd.com/ama64, 2024-10) — named figure, independent
  • Bryan Johnson — Blueprint protocol (blueprint.bryanjohnson.com), tirzepatide microdose discontinuation X thread 2025-01-30 — named figure, commercial motive
  • Dr. Brad Stanfield (drstanfield.com, 2025) — microdose-skeptic anchor
  • Layne Norton — BioLayne Podcast Ep. 18 (biolayne.com) — sarcopenia / leucine threshold
  • Mark Hyman — drhyman.com eps. 848 / 884 / 992 (2024–2025) — anti-GLP-1 metabolic-health wing
  • Washington Post “What is ‘Ozempic personality’” (washingtonpost.com/health/2026/04/16), Boston Globe (bostonglobe.com/2026/04/16), KTLA, NZ Herald — “Ozempic personality” cluster
  • UNC Health News, news.unchealthcare.org, 2025-02 — AUD trial press release
  • Novo Nordisk: NovoCare pricing (novocare.com, accessed 2026-05); $499 / $349 / $199 self-pay press releases (prnewswire.com, 2025-03-05, 2025-03-24, 2025-11-17)
  • Hims & Hers: news.hims.com 2026-02-05 (compounded pill launch); FDA warning letters CDER MARCS-CMS 716567 / 716825 Sept 2025; 9 March 2026 brand-only pivot
  • Mochi Health (joinmochi.com, 2026); Henry Meds; Aequita pharmacy WA DOH action February 2026 per KING 5
  • GitelCare (gitelcare.com, 2025) — 68–122% potency assay range; Empower fourth FDA warning letter April 2025
  • Pharmacy Times (pharmacytimes.com, 2025) — >455 FDA AE reports for compounded semaglutide
  • Orrick (orrick.com, 2026-05) — 30 April 2026 FDA proposal to exclude semaglutide from 503B bulks list
  • APA Online (blog.apaonline.org/2024/06/12, 2024-06) — “food noise” origin / r/WegovyWeightLoss anchor
  • Subreddits referenced but not directly retrievable in Pass 2: r/Semaglutide, r/Ozempic, r/WegovyWeightLoss, r/Peptides, r/PeptideUmbrella, r/Biohackers, r/Nootropics, r/loseit, r/longevity, r/Mounjaro — flagged as a known retrieval gap

14. Audit / Refresh Trail

  • Composed: 13 May 2026
  • Science-layer source: semaglutide_sci_2026-05-13_S95.md (Pass 1; last refreshed 13 May 2026 vs prior 11 May 2026)
  • Community-layer source: semaglutide_com_2026-05-13_C92.md (Pass 2; 13 May 2026)
  • Calibration reference: retatrutide_mono_2026-05-12_B60-C52.md (first complete methodology pass) and tirzepatide_mono_2026-05-13_S95-C81.md (closest peer compound)
  • Next refresh triggers:
    • (a) Any pivotal-trial publication or sNDA approval extending the indication set (notably CagriSema FDA decision; STAR primary publication; SURPASS-CVOT class read-across)
    • (b) FDA finalization of the 30 April 2026 proposal to exclude semaglutide from the 503B bulks list (comment period closes 29 June 2026)
    • (c) Any new pharmacovigilance signal — particularly any formal pharma or regulatory acknowledgment of “Ozempic personality” / anhedonia as a labeled ADR
    • (d) Any retraction of cited primary literature (verified clean as of 13 May 2026)
    • (e) Any controlled trial of microdose semaglutide (0.125–0.25 mg/wk) in non-obese adults — currently zero registered
    • (f) Major shift in vendor landscape: NovoCare pricing changes, additional compounder lawsuits or shutdowns, FDA enforcement actions against research-chemical channels
    • (g) Direct Reddit thread pull (r/Semaglutide, r/Ozempic, r/WegovyWeightLoss, r/Peptides) to close the community-source retrieval gap noted in Pass 2
    • (h) STEP TEENS Weight Maintenance (NCT06571383) and ESSENCE Part 2 cirrhotic-outcome readouts (2029)