Compound category
- Semaglutide
- Incretin mimetic
- Liraglutide
- Incretin mimetic
Compound comparison
Semaglutide vs Liraglutide
Quick Answer
Liraglutide vs semaglutide comes down first to identity: semaglutide (C187H291N45O59, 4114 Da, CAS 910463-68-2) is 363 Da heavier than liraglutide (C172H265N43O51, 3751 Da, CAS 204656-20-2). Both are synthetic peptide incretin mimetics. Semaglutide has published phase 3 trial reports; no head-to-head study comparing the two is cited in this comparison.
Compound Reference Pages
Semaglutide vs Liraglutide: At a Glance
Molecular class
- Semaglutide
- Synthetic peptide
- Liraglutide
- Synthetic peptide
Mechanism of action
- Semaglutide
- Not established in published sources
- Liraglutide
- Not established in published sources
Amino acid sequence
- Semaglutide
- Not established in published sources
- Liraglutide
- Not established in published sources
CAS number
- Semaglutide
- 910463-68-2
- Liraglutide
- 204656-20-2
Molecular formula
- Semaglutide
- C187H291N45O59
- Liraglutide
- C172H265N43O51
Molecular weight
- Semaglutide
- 4114 Da
- Liraglutide
- 3751 Da
InChIKey
- Semaglutide
- DLSWIYLPEUIQAV-CCUURXOWSA-N
- Liraglutide
- YSDQQAXHVYUZIW-QCIJIYAXSA-N
Highest published human trial stage
- Semaglutide
- Phase 3
- Liraglutide
- Not established in published sources
Regulatory status
- Semaglutide
- First global approval reported in 2018
- Liraglutide
- Not established in published sources
Formulations described in published literature
- Semaglutide
- Subcutaneous and oral
- Liraglutide
- Not established in published sources
Head-to-head comparative study
- Semaglutide
- Not established in published sources
- Liraglutide
- Not established in published sources
Purity standard
- Semaglutide
- ≥99% by HPLC
- Liraglutide
- ≥99% by HPLC
Semaglutide compared with Liraglutide across mechanism, structure and research attributes. Research reference only.
How Semaglutide and Liraglutide Differ in Research
Semaglutide and liraglutide differ at the formula level by exactly C15H26N2O8, which is why semaglutide records 4114 Da against 3751 Da for liraglutide, a gap of 363 Da. That gap is large enough to separate the two cleanly by mass spectrometry, and the two compounds also carry distinct InChIKeys (DLSWIYLPEUIQAV-CCUURXOWSA-N for semaglutide, YSDQQAXHVYUZIW-QCIJIYAXSA-N for liraglutide) and distinct CAS numbers (910463-68-2 and 204656-20-2).
For a laboratory receiving either material, those identifiers are the practical test of what is in the vial: an observed mass near 3751 Da on a sample labelled semaglutide is a misidentification, not a batch variation. Residue-level sequence data for either compound is not established in the sources this comparison relies on, so the formula difference cannot be assigned here to specific residues or side-chain groups.
Both compounds sit in the incretin-mimetic category, but the molecular mechanism of neither is characterised in the sources this page draws on. A 2023 JCI insight paper names semaglutide in its title as a glucagon-like peptide-1 (GLP-1) analogue; no equivalent receptor-level description is available here for liraglutide.
The error that recurs most often in secondary listings is treating liraglutide and semaglutide as one compound with two trade identities, or copying one compound's CAS number or mass into the other's record. The identifiers rule that out: 15 extra carbons and 8 extra oxygens separate the formulas.
The two evidence bases are not the same size, and the comparison is lopsided because of it. Semaglutide carries randomised phase 3 trial reports, including SUSTAIN 1 (a phase 3a placebo-controlled trial in type 2 diabetes published in 2017) and STEP 2 (a phase 3 trial of a 2.4 mg weekly regimen published in 2021), alongside a 2018 report of its first global approval and a 2024 systematic review of its clinical pharmacokinetics.
Preclinical semaglutide work extends to rodents, where a 2020 JCI insight study reported body-weight reduction mediated through distributed neural pathways. Liraglutide's record here is far thinner: one published report examined its effect on energy intake in adolescents with persistent obesity after vertical sleeve gastrectomy, and that title does not disclose a trial phase or design.
No direct comparative study of semaglutide and liraglutide is cited, so the two columns above describe separate datasets rather than a measured contrast. All material discussed on this page is supplied strictly for in-vitro laboratory research use and is not for human or veterinary use.
Semaglutide vs Liraglutide: Frequently Asked Questions
What is the difference between Semaglutide and Liraglutide?
Semaglutide (C187H291N45O59, 4114 Da, CAS 910463-68-2) is 363 Da heavier than liraglutide (C172H265N43O51, 3751 Da, CAS 204656-20-2). Both are classified as synthetic peptide incretin mimetics. Semaglutide has published phase 3 trial reports such as SUSTAIN 1 and STEP 2, while no trial phase is established in published sources for liraglutide in this comparison.
Is there a head-to-head study of liraglutide vs semaglutide?
No head-to-head study of liraglutide vs semaglutide is cited in this comparison. Semaglutide's published data include phase 3 randomised trials and rodent work, while liraglutide's cited record is a single report on energy intake in adolescents after vertical sleeve gastrectomy. Placing the two side by side therefore compares separate datasets, not results measured against each other in one study.
What is the molecular weight of semaglutide and liraglutide?
Semaglutide has a molecular weight of 4114 Da and liraglutide has a molecular weight of 3751 Da, a difference of 363 Da. The gap corresponds to a formula difference of C15H26N2O8 between C187H291N45O59 for semaglutide and C172H265N43O51 for liraglutide, which allows mass spectrometry to distinguish the two research materials.
What are the CAS numbers of semaglutide and liraglutide?
Semaglutide is CAS 910463-68-2 and liraglutide is CAS 204656-20-2. Their InChIKeys also differ: DLSWIYLPEUIQAV-CCUURXOWSA-N for semaglutide and YSDQQAXHVYUZIW-QCIJIYAXSA-N for liraglutide.
Does liraglutide have human trial data?
Liraglutide has at least one published human report, examining energy intake in adolescents with persistent obesity after vertical sleeve gastrectomy, but its trial phase and design are not established in the sources behind this comparison. Semaglutide, by contrast, has published phase 3 reports including SUSTAIN 1 and STEP 2. Both compounds are supplied for in-vitro laboratory research use only.
References
- Sorli C, Harashima SI, Tsoukas GM, et al. "Efficacy and safety of once-weekly semaglutide monotherapy versus placebo in patients with type 2 diabetes (SUSTAIN 1): a double-blind, randomised, placebo-controlled, parallel-group, multinational, multicentre phase 3a trial." The lancet. Diabetes & endocrinology, 2017. Read the Sorli 2017 record on PubMed: Efficacy and safety of once-weekly semaglutide monotherapy versus placebo in patients with type 2 diabetes (SUSTAIN 1): a double-blind, randomised, placebo-controlled, parallel-group, multinational, multicentre phase 3a trial
- Davies M, Færch L, Jeppesen OK, et al. "Semaglutide 2·4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2): a randomised, double-blind, double-dummy, placebo-controlled, phase 3 trial." Lancet (London, England), 2021. Read the Davies 2021 record on PubMed: Semaglutide 2·4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2): a randomised, double-blind, double-dummy, placebo-controlled, phase 3 trial
- Dhillon S. "Semaglutide: First Global Approval." Drugs, 2018. Read the Dhillon 2018 record on PubMed: Semaglutide: First Global Approval
- Meier JJ. "Efficacy of Semaglutide in a Subcutaneous and an Oral Formulation." Frontiers in endocrinology, 2021. Read the Meier 2021 record on PubMed: Efficacy of Semaglutide in a Subcutaneous and an Oral Formulation
- Yang XD, Yang YY. "Clinical Pharmacokinetics of Semaglutide: A Systematic Review." Drug design, development and therapy, 2024. Read the Yang 2024 record on PubMed: Clinical Pharmacokinetics of Semaglutide: A Systematic Review
- Gabery S, Salinas CG, Paulsen SJ, et al. "Semaglutide lowers body weight in rodents via distributed neural pathways." JCI insight, 2020. Read the Gabery 2020 record on PubMed: Semaglutide lowers body weight in rodents via distributed neural pathways
- Chuong V, Farokhnia M, Khom S, et al. "The glucagon-like peptide-1 (GLP-1) analogue semaglutide reduces alcohol drinking and modulates central GABA neurotransmission." JCI insight, 2023. Read the Chuong 2023 record on PubMed: The glucagon-like peptide-1 (GLP-1) analogue semaglutide reduces alcohol drinking and modulates central GABA neurotransmission
- Effects of Liraglutide on Energy Intake in Adolescents With Persistent Obesity After Vertical Sleeve Gastrectomy. PMID 42538646. Read the PubMed record: Effects of Liraglutide on Energy Intake in Adolescents With Persistent Obesity After Vertical Sleeve Gastrectomy.
How This Page Is Sourced
Compiled by the Peptide.Express Research Team. Written and reviewed by Peptide.Express Editorial Team. Molecular identity on this page (name, CAS number, molecular formula and molecular weight) is resolved from a single internal entity record and checked against primary registries (PubChem, CAS Common Chemistry) rather than retyped per page. A field with no verified value is left out instead of estimated. Literature is cited to a DOI, PMID or PMCID permalink so every reference resolves to the specific record it names.
Research Use Only. All products listed on Peptide.Express are intended for laboratory research and educational purposes only. Comparisons describe receptor pharmacology and structure for research context — no human or therapeutic use is implied.