ES 
EN 
DE 
A research-focused comparison of Melanotan II and PT-141, covering melanocortin receptor selectivity, evidence, safety signals and regulatory status.
Insulin is an anabolic hormone that regulates energy balance — it lowers blood glucose and promotes energy storage, including in adipose tissue. Insulin resistance is a state in which cells respond more weakly to insulin, which leads to a compensatory rise in its concentration. This article describes what research says about the role of insulin in lipogenesis — the mechanism only, not recommendations.
This article is educational in character and constitutes a review of the published scientific literature on the physiology of metabolism. It is not medical, dietary or diagnostic advice; it does not serve to diagnose, treat or prevent insulin resistance. Insulin resistance is a clinical condition whose assessment and management rest solely with a physician. The text describes biochemical mechanisms, not guidance for action.
Insulin is a hormone secreted by the pancreatic β cells in response to a rise in blood glucose, mainly after a meal. Its overriding function is to lower glycaemia and switch metabolism into energy-storage mode. It acts as a signal: “energy available — lay down reserves”.
At the cellular level, insulin binds to the insulin receptor and triggers a signalling cascade whose most important effects are:
The last two points make insulin the central hormone in the context of fat storage.
Lipogenesis is the process of fat synthesis. Insulin influences it through several parallel routes that together shift the balance of adipose tissue towards storage.
Activation of lipoprotein lipase (LPL). Insulin stimulates LPL — an enzyme on the surface of the blood vessels of adipose tissue that “unpacks” circulating triglycerides from lipoproteins, enabling the uptake of fatty acids by adipocytes and their storage.
De novo lipogenesis. Under conditions of energy excess and high insulin, part of the glucose can be converted into fatty acids in the liver and adipose tissue (de novo lipogenesis). Insulin activates the transcription factors and enzymes of this pathway.
Suppression of lipolysis. Insulin strongly inhibits hormone-sensitive lipase (HSL) in adipocytes — the enzyme that releases fatty acids from stored triglycerides. As long as insulin is high, the release of fat from the stores is suppressed.
The net result of these actions points in one clear direction: high insulin promotes fat storage and inhibits its release. This is a description of the hormone’s physiological role, not a value judgement or a suggestion of any course of action (Saltiel and Kahn, 2001).
Insulin resistance is a state in which the target tissues — muscle, liver, adipose tissue — respond more weakly to the action of insulin. To achieve the same effect on glucose concentration, the pancreas must secrete more insulin. This produces a state of compensatory hyperinsulinaemia — a chronically elevated insulin concentration.
The mechanisms leading to insulin resistance are manifold and still under investigation: they include, among others, the deposition of fat in “ectopic” sites (liver, muscle), chronic inflammation of adipose tissue, disturbances of intracellular signalling and mitochondrial dysfunction. Insulin resistance is one of the central elements of metabolic syndrome and precedes the development of type 2 diabetes (Czech, 2017; DeFronzo and Tripathy, 2009).
The literature assigns a particular role to ectopic fat and the phenomenon of lipotoxicity. When the storage capacity of the “proper” (subcutaneous) adipose tissue is exceeded, lipids begin to deposit in organs not intended for the purpose — above all the liver and skeletal muscle. The intermediate products of lipid metabolism that accumulate there disturb intracellular insulin signalling, intensifying the insulin resistance of these tissues. On this view, it is not so much the amount of fat as its distribution and the storage capacity of the adipocytes that are associated with insulin resistance — which explains why people of a similar body weight may differ in insulin sensitivity.
Insulin resistance is a clinical condition with a complex aetiology. Its diagnosis, assessment and any management rest solely with a physician. This description concerns the physiological mechanism and does not replace medical assessment or constitute diagnostic guidance.
The link between insulin resistance and adipose tissue is sometimes presented as a “vicious circle”, but in the scientific literature it is a two-way relationship whose causal direction cannot be reduced to a single sentence.
On one hand, an excess of adipose tissue, particularly visceral, is associated with greater insulin resistance — through the release of free fatty acids, inflammatory cytokines and the disruption of insulin signalling. On the other, the chronic hyperinsulinaemia that accompanies insulin resistance promotes — in line with the lipogenesis mechanism described above — fat storage and the inhibition of its release.
What is scientifically important is that insulin resistance is not itself synonymous with “putting on weight”, and the cause-and-effect relationship between hyperinsulinaemia and weight gain remains the subject of active debate (discussed below). The literature describes correlations and mechanisms, but attributing weight gain to insulin alone is an oversimplification. This is an area in which interpretative caution is especially important.
The role of insulin in weight gain is the subject of one of the loudest debates in contemporary obesity science. Two models compete to explain the phenomenon — and both are worth knowing, because public messaging often presents one of them as settled.
The carbohydrate-insulin model (CIM). On this account (represented among others by Ludwig and Ebbeling), it is a diet with a high glycaemic load that raises insulin, which directs energy into the fat stores, reducing its availability to the rest of the body — which in turn intensifies hunger and lowers expenditure. Here insulin is treated as the causal “conductor” of storage (Ludwig and Ebbeling, 2018).
The energy balance model (EBM). The opposing position (represented among others by Hall) emphasises that an energy surplus is the primary cause of weight gain, and that the role of diet composition and insulin is secondary and smaller than the CIM assumes. Controlled studies comparing diets of differing glycaemic load at matched energy did not show the large advantage predicted by the carbohydrate-insulin model (Hall and Guo, 2017).
The state of the debate can be summarised honestly: insulin undoubtedly regulates fat storage at the level of mechanism, but whether it is the primary cause of obesity, or rather one element within energy balance, remains unresolved. This article reports the dispute; it does not resolve it or derive any dietary recommendations from it.
Insulin-resistant adipose tissue is the subject of research into new pharmacological targets connected with the energy metabolism of adipocytes. One of these is the enzyme NNMT (Nicotinamide N-Methyltransferase), whose activity is sometimes elevated in adipose tissue in states of obesity and insulin resistance.
NNMT participates in the metabolism of nicotinamide and the cellular pool of the coenzyme NAD+. In animal models, lowering its activity has been associated with a favourable metabolic profile of adipose tissue (Kraus et al., 2014). A selective NNMT inhibitor studied in preclinical models is 5-amino-1MQ — a pharmacological tool analysed in adipocyte cultures and mouse models of obesity. The mechanism of NNMT and 5-amino-1MQ is expanded in a separate article. It must be emphasised that the data on this molecule are exclusively preclinical — there are no published human studies.
A second point of contact with metabolic pharmacology is the incretin axis: the GLP-1 and GIP receptors influence insulin homeostasis, and agonists of these receptors are being analysed in research on insulin sensitivity. The mechanism of the incretins is described in a separate article on GLP-1, GIP and glucagon.
| Area | Model / source | Observation | Type of evidence |
|---|---|---|---|
| Insulin signalling and lipogenesis | Review (Saltiel and Kahn 2001) | Insulin promotes storage, inhibits lipolysis | Mechanistic |
| Insulin resistance in obesity | Review (Czech 2017) | A complex, two-way relationship with adipose tissue | Review |
| Carbohydrate-insulin model | Hypothesis (Ludwig and Ebbeling 2018) | Insulin as the causal regulator of storage | Hypothesis / debate |
| Energy balance model | Reviews/studies (Hall and Guo 2017) | The primary role of an energy surplus | Controlled studies / debate |
| NNMT in adipose tissue | Mouse / cell (Kraus 2014) | Lowering NNMT and the metabolic profile of adipocytes | Preclinical |
The mechanisms of adipose-tissue metabolism and insulin sensitivity are the subject of laboratory research. The One-Peptides catalogue offers compounds analysed in this context, including 5-amino-1MQ (a selective NNMT inhibitor, studied in adipocyte metabolism) and agonists of the incretin axis. These are chemical reagents intended solely for laboratory research (Research Use Only) — not medicines, supplements or products for use in humans, and in particular not agents “for insulin resistance”. The broader context of metabolic pharmacology is organised by the guide to GLP-1 peptides and metabolism.
How does insulin affect fat storage?
Insulin promotes fat storage through several routes: it activates lipoprotein lipase (the uptake of fatty acids by adipocytes), supports de novo lipogenesis and inhibits hormone-sensitive lipase (the release of fat from the stores). On balance, high insulin shifts the balance of adipose tissue towards storage. This is a description of the physiological mechanism.
What is insulin resistance?
It is a state in which tissues respond more weakly to insulin, so the pancreas secretes more of it (compensatory hyperinsulinaemia). It is one of the central elements of metabolic syndrome and precedes type 2 diabetes. Its diagnosis and assessment rest with a physician.
Does insulin resistance cause weight gain?
The relationship between insulin resistance, hyperinsulinaemia and body weight is two-way and remains the subject of scientific debate (the carbohydrate-insulin model vs the energy balance model). The literature describes mechanisms and correlations, but attributing weight gain to insulin alone is an oversimplification. The article reports the state of the research; it does not formulate a resolution or recommendations.
What is the carbohydrate-insulin model?
It is a hypothesis according to which a diet with a high glycaemic load raises insulin, directing energy into the fat stores. The competing model (energy balance) emphasises the primary role of an energy surplus. Both are the subject of active scientific debate; neither is presented here as settled.
What is NNMT and how is it connected with adipose tissue?
NNMT is an enzyme involved in the metabolism of nicotinamide and the NAD+ pool. Its activity is sometimes elevated in adipose tissue in obesity and insulin resistance. In animal models, lowering NNMT has been associated with a favourable metabolic profile of adipocytes. This is a research direction at the preclinical stage, analysed among other things using the inhibitor 5-amino-1MQ.
Why do people of a similar body weight differ in insulin sensitivity?
The literature attributes this among other things to the distribution of fat and the storage capacity of the subcutaneous tissue. When it is exceeded, lipids deposit ectopically — in the liver and muscle — disturbing insulin signalling there. It is not so much the amount of fat as its location that is associated with insulin resistance. This is a description of the mechanism, not a diagnostic criterion.
The content is educational in character and constitutes a review of the published scientific literature on the physiology of metabolism. It does not constitute medical, dietary or diagnostic advice; it does not serve to diagnose, treat or prevent insulin resistance, hyperinsulinaemia or metabolic syndrome. Insulin resistance is a clinical condition — its assessment and management rest solely with a physician. The article contains no dietary, supplementation or diagnostic recommendations. The substances mentioned in the text (5-amino-1MQ, incretin agonists) are chemical reagents intended solely for laboratory research (Research Use Only) — not medicines, supplements or products for consumption, and in particular not agents “for insulin resistance”. The data on 5-amino-1MQ come exclusively from preclinical models.
A research-focused comparison of Melanotan II and PT-141, covering melanocortin receptor selectivity, evidence, safety signals and regulatory status.
A research comparison of MK-677 and ipamorelin, focusing on GHS-R1a signaling, selectivity, administration route, human evidence and WADA status.
We offer a wide selection of peptides tailored to a range of laboratory analytical needs.
Every batch is tested for identity and purity (HPLC, MS) and comes with a certificate of analysis.
We invest in analytical testing and full batch documentation for every product.
Nuestras numerosas reseñas positivas reflejan la satisfacción de nuestros clientes que siguen regresando por más.
¡Suscríbete al boletín!
Obtén un 10% de descuento en tu primera compra
One-Peptides.com
Información
© 2026 ONE-PEPTIDES.COM