SEMA G 2mg PEN

Sema G – Chemical reagent intended exclusively for laboratory research (Research Use Only). It is not a medicinal product, dietary supplement or foodstuff. It is not intended for use in humans or animals. Sold exclusively to registered research entities and laboratories.

SEMA G 2 mg PEN is a research reagent in the form of an applicator with a factory-made solution. The active substance — semaglutide — is also marketed as a medicinal product registered by the EMA and FDA under the trade names Ozempic® (type 2 diabetes), Wegovy® (obesity) and Rybelsus® (oral form), likewise in a pen format.

These two occurrences of the same peptide represent two distinct regulatory frameworks. The RUO applicator in the Pro-Body catalogue is not a medicinal product, is not intended for use in humans and is not subject to pharmaceutical regulation. The Novo Nordisk pen derives from EMA/FDA registration, is available by prescription only and requires medical supervision.

The Semaglutide RUO reagent is not a substitute for a medicinal product and does not replace medical consultation. The identity of the active substance does not abolish this boundary.

In 2021 the FDA approved semaglutide as a drug for chronic overweight — a year later search-engine queries for this peptide soared. The reason is simple: semaglutide is one of the most clinically well-documented peptides of the past decade. A GLP-1 receptor monoagonist on which the entire contemporary landscape of incretin pharmacology is based. The reference literature lists the SUSTAIN (type 2 diabetes) and STEP (obesity) programs, with endpoints reported in the NEJM and Lancet.

The molecule was developed by Novo Nordisk, and it is this company that holds the registration of Ozempic®, Wegovy® and Rybelsus®. In metabolic research on obesity, semaglutide remains the prototype for an entire generation of weight-loss peptides based on the incretin axis. This reagent is supplied in the format of an applicator with a factory-made solution, nominal concentration of 2 mg of semaglutide per applicator.

This is the starting/titration variant in the Pro-Body line — the lowest nominal peptide concentration, dedicated to low-dose protocols and titration series in which the researcher builds a concentration–response curve from a low baseline value. The line also offers, in parallel, the standard variant SEMA G 4mg as well as higher variants.

What semaglutide is — sequence and class

Semaglutide is a GLP-1 receptor (GLP-1R) monoagonist — a stabilized analogue of the endogenous glucagon-like peptide 1. The molecule comprises 31 amino acids, molecular mass of approximately 4113 Da. Relative to human GLP-1, structural modifications were introduced to stabilize the peptide against enzymatic degradation and to prolong the half-life. C18 fatty-acid acylation — the attached chain enables reversible binding to serum albumin.

Albumin acts as a reservoir: the molecule circulates partly bound, is gradually released and degraded. The effect is a serum half-life of approximately 7 days (weekly regimen in the clinical protocols of Ozempic® and Wegovy®). The substance was developed by Novo Nordisk. FDA registrations: Ozempic® 2017 (T2 diabetes), Rybelsus® 2019 (oral form), Wegovy® 2021 (obesity). The EMA approved analogous indications in the EU.

Chemical characteristics

Activation of the GLP-1 receptor triggers a cascade of four complementary mechanisms reported in the clinical and preclinical literature. GLP-1R is a G protein-coupled receptor — in practice this means that agonist binding translates into an increase in intracellular cAMP and the activation of signalling pathways dependent on the kinase PKA.

1. Glucose-dependent insulin secretion. In pancreatic β cells, GLP-1R activation increases the cAMP concentration, which potentiates insulin release in response to a glucose load. The mechanism is glucose-dependent — under normoglycemia, insulin secretion is not significantly stimulated. This is a molecular “fuse”: the signal is amplified only when glucose is already elevated.
2. Inhibition of glucagon secretion postprandially in pancreatic α cells — combined with insulin stimulation it provides two-point control of postprandial glycemia.
3. Central action — appetite modulation. GLP-1R in the arcuate nucleus of the hypothalamus mediates satiety signalling (POMC neuron activation). In experimental practice: semaglutide prolongs the satiety signal — like a “enough eating” button held down longer.
4. Slowing of gastric emptying additionally prolongs satiety after a meal.

Reference data come from Novo Nordisk research programs: SUSTAIN (Marso et al. 2016, SUSTAIN-6 — cardiovascular endpoints in type 2 diabetes) and STEP (Wilding et al. 2021, STEP-1 — obesity). In STEP-1 (a multicenter RCT, phase 3) a mean reduction in body weight of approximately 14.9% was reported at 68 weeks of intervention with semaglutide 2.4 mg weekly vs placebo.

The active substance is the same (semaglutide); the products come from two distinct regulatory lines with different documentation and intended use. The Novo Nordisk pen is a medicinal product with a patient package leaflet, SmPC and EMA pharmacovigilance supervision. The RUO applicator in the Pro-Body catalogue is a chemical reagent with analytical documentation (COA, HPLC, MS). The identity of the peptide does not abolish the distinction of regulatory frameworks.

SEMA G PEN as an RUO reagent finds use in several directions. The format of an applicator with a factory-made solution and, in the case of the 2 mg variant, with the lowest nominal peptide concentration in the line, is particularly well suited to low-dose protocols and titration series, where the researcher builds a concentration–response curve from a low baseline value.

• Pharmacology of the GLP-1 axis. Analyses of receptor activity, profiling of GLP-1R selectivity, EC50 measurements in cell cultures with cAMP and β-arrestin reporters. The applicator format facilitates precise withdrawal of solution for serial dilutions.
• Animal models of insulin resistance and obesity. DIO mice, ob/ob and db/db models, Zucker rats. Endpoints: body weight, composition (DEXA, NMR), OGTT/ITT, HOMA-IR, lipid profile. Semaglutide functions as a reference GLP-1R mono-agonist for comparisons with newer analogues.
• Pharmacokinetics and central action on appetite. PK profile of acylated GLP-1 analogues, kinetics of albumin binding, behavioural models of satiety, POMC neuron activation in the arcuate nucleus.
• Comparative analyses with other GLP-1 analogues — liraglutide, dulaglutide, exenatide, tirzepatide (dual GLP-1R/GIPR). Semaglutide as a reference mono-agonist for SAR work (structure–activity relationship); in head-to-head protocols a frequent point of reference is the dual incretin agonist Tirzepatide 5mg.

REGULATORY STATUS

Semaglutide as a drug (Ozempic®, Wegovy®, Rybelsus®) is registered by the EMA and FDA and available by prescription only. SEMA G 2 mg PEN (RUO) does not have the status of a medicinal product or EMA/FDA authorization as a drug. Peptides from the class of GLP-1 agonists are not currently listed directly as a separate category on the current WADA prohibited list — the status may change in subsequent editions. Registered athletes (ADAMS) must check the current list of prohibited substances before any decision regarding use.

A direct comparison of semaglutide with a dual GIP/GLP-1 agonist — including the results of head-to-head studies — is discussed in the article Tirzepatide vs Semaglutide — which is better for weight loss. The mechanism of the next-generation triple GLP-1/GIP/GCG agonist, available in the Pro-Body catalogue as Retatrutide pen 5mg, is described in the publication Retatrutide for obesity — action and effects of use.

1. Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, et al. (2021). Once-Weekly Semaglutide in Adults with Overweight or Obesity. PubMed
2. Marso SP, Bain SC, Consoli A, Eliaschewitz FG, Jódar E, Leiter LA, et al. (2016). Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes. PubMed
3. Frías JP, Davies MJ, Rosenstock J, Pérez Manghi FC, Fernández Landó L, Bergman BK, et al. (2021). Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. PubMed
4. Davies M, Færch L, Jeppesen OK, Pakseresht A, Pedersen SD, Perreault L, et al. (2021). Semaglutide 2·4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2). PubMed
5. Lau J, Bloch P, Schäffer L, Pettersson I, Spetzler J, Kofoed J, et al. (2015). Discovery of the Once-Weekly Glucagon-Like Peptide-1 (GLP-1) Analogue Semaglutide. PubMed