Metabolic Peptides
19Mitochondrial-derived peptides and metabolic modulators are researched for their effects on insulin sensitivity, energy expenditure, and metabolic flexibility. MOTS-C and AICAR are among the most studied compounds in this area.
5-Amino-1MQ
A pill that aims to switch fat cells from 'storage mode' to 'burning mode' by blocking an enzyme (NNMT) that is overactive in the fat tissue of overweight people. Not technically a peptide, but commonly sold alongside them. Unlike appetite suppressants, this targets the fat cells directly rather than making you eat less. The science is promising in lab studies, but there are no completed human trials yet.
AICAR
A natural compound that activates your cells' energy sensor — the same pathway that turns on during exercise. Mimics the metabolic effects of endurance exercise at the cellular level, helping with fat burning, glucose uptake, and building more mitochondria. Banned by WADA as a metabolic modulator after detection in professional cycling.
AT7687
A novel obesity drug from Danish biotech Antag Therapeutics that takes a completely different approach — instead of suppressing appetite like all the GLP-1 drugs, it stops fat from being stored in the first place by blocking the GIP receptor in fat cells. First-in-human Phase 1 trial completed in 2026 showed it is well tolerated, with mild GI side effects, and produced reductions in LDL cholesterol and resting heart rate alongside weight loss signals.
Danuglipron
Pfizer's once-failed attempt at an oral GLP-1 weight loss pill (code name PF-06882961). Despite producing meaningful weight loss in Phase 2 trials, Pfizer discontinued development in 2025 after reports of potential liver injury in a healthy volunteer. Included here because it remains heavily searched as the cautionary tale of the oral GLP-1 race — and because Pfizer is now developing alternative oral GLP-1 candidates after the danuglipron setback.
Ecnoglutide
A long-acting weekly GLP-1 weight loss injection from Chinese biotech Sciwind Biosciences. Uses a special protein-extension technology to last longer in the body than semaglutide. Late-stage Phase 3 trials in China showed body weight loss of 14-15% in obesity and good blood-sugar control in type 2 diabetes. Approval in China is expected first, with international filings to follow. One of several Chinese-developed GLP-1s reaching the global market.
GLP-1
The natural appetite hormone that your gut produces after eating — it's what all GLP-1 weight loss drugs (semaglutide, tirzepatide, etc.) are designed to copy. Your body makes it naturally, but it breaks down within 1-2 minutes, which is far too fast to use as a medicine. That's why drug companies created modified versions that last days instead of minutes. Included here because understanding GLP-1 is key to understanding the entire class of modern weight loss drugs.
Humanin
A 24-amino-acid peptide naturally produced by mitochondria. Related to MOTS-c but works differently. Protects cells against oxidative stress, cell death, and age-related damage by interacting with proteins involved in apoptosis and IGF signaling. One of the most studied peptides in longevity research, with evidence that levels decline in aging tissues.
Insulin
The most powerful muscle-building hormone in your body — it drives nutrients (sugar, amino acids) directly into muscle cells. FDA-approved and essential for diabetes management. In bodybuilding, it's used for extreme muscle growth by forcing nutrients into muscles after workouts. However, it is the single most dangerous compound used in performance enhancement — a dosing error can cause seizures, brain damage, coma, or death within hours. The margin between an effective dose and a lethal dose is very small.
Kisspeptin-54
The full-length 54-amino-acid form of kisspeptin — the master regulator of reproductive hormones. More potent and longer-acting than Kisspeptin-10. Being studied for fertility treatment, low testosterone diagnosis, and reproductive disorders. May offer a more natural approach to stimulating reproductive hormone production than GnRH or HCG.
Klotho
A natural anti-ageing protein your body produces, named after the Greek goddess who spun the thread of life. Mice without it age extremely rapidly; mice with extra Klotho live up to 30% longer. Recent research shows it counters the majority of the 12 hallmarks of ageing — reducing cellular senescence, oxidative damage, fibrosis, and inflammation. Recombinant human Klotho is in early clinical trials. Currently more of a research target than a usable therapeutic.
L-Carnitine
A natural substance your body already makes that acts as a 'shuttle' to carry fat into your cells' energy factories (mitochondria) where it gets burned for fuel. Without enough carnitine, your body literally cannot burn long-chain fats for energy. One of the most popular and well-studied fat metabolism supplements available. Has FDA-approved forms for people with carnitine deficiency, and is widely available over the counter as a supplement.
Lipo-C
A vitamin and amino acid injection commonly offered at weight loss clinics to support fat metabolism. Contains a mix of nutrients (methionine, inositol, choline, B vitamins, and L-carnitine) that help your liver process and export fat, and help your cells burn fat for energy. Think of it as a metabolic support shot — it's not a standalone weight loss treatment, but is used alongside diet and exercise to help your body process fat more efficiently.
Liraglutide
A GLP-1 medication that mimics a natural gut hormone (97% similar to native GLP-1) and is the predecessor to semaglutide. FDA-approved for both type 2 diabetes (Victoza) and obesity (Saxenda). One of the most prescribed weight loss medications worldwide, with extensive long-term safety data including reduced risk of heart attack and stroke in diabetic patients.
MOTS-C
A small peptide that comes from your mitochondria (the energy factories in your cells). It acts like an 'exercise mimetic' — it can produce many of the metabolic benefits of working out without actually exercising, such as improving how your body handles sugar and burns fat. Discovered in 2015, it was one of the first signaling molecules found to be encoded by mitochondrial DNA rather than the main DNA in your cell nucleus.
NAD+
A molecule your body needs for hundreds of essential processes — making energy, repairing DNA, and regulating genes. Your NAD+ levels drop by about half between ages 40 and 60, which may contribute to aging and mitochondrial decline. People supplement with IV infusions, oral pills (NMN or NR), or injections to try to restore levels toward what they had when younger.
Orforglipron
The first weight loss drug in the GLP-1 class that comes as a daily pill rather than a weekly injection — and unlike Rybelsus, you can take it with food and water. Made by Eli Lilly, it is technically a small molecule rather than a peptide, but it activates the same GLP-1 receptor as semaglutide and tirzepatide. Phase 3 trials in 2026 (ACHIEVE-1 in diabetes, ATTAIN-1 and ATTAIN-2 in obesity) have shown around 14-15% body weight loss. Likely to be the first oral GLP-1 to compete on weight loss with the injectables.
Pemvidutide
A weekly weight loss injection from Altimmune that targets two hormones (GLP-1 for appetite, glucagon for fat-burning) — similar to mazdutide and survodutide. Particularly being developed for fatty liver disease (MASH) alongside obesity. Phase 2b results showed around 15.6% body weight loss at 48 weeks, with significant reductions in liver fat. Also branded as ALT-801. Now in Phase 3 trials for both indications.
SLU-PP-332
A compound developed at Washington University that activates estrogen-related receptor alpha. A next-generation exercise mimetic that enhances endurance and promotes slow-twitch muscle fiber transformation through a different mechanism than AICAR. Activates the same gene programs that endurance training induces, including mitochondrial growth and fat-burning metabolism.
Vitamin B12
An essential vitamin required for DNA synthesis, nerve function (myelin maintenance), and red blood cell formation. Deficiency is common, particularly in vegans, the elderly, those on metformin or proton pump inhibitors, and individuals with pernicious anemia. Injectable forms bypass the complex gut absorption pathway, making them the treatment of choice for severe deficiency and malabsorption.