Peptides Simplified
Peptides, explained in plain English.
Your compass for peptide research. What a peptide is, why they are suddenly everywhere, and what studies actually show for 44 of the most talked-about ones. No hype, no jargon.
The basics
What is a peptide?
Everything in your body that is made of protein, from muscle to hormones, is built from 20 amino acids. Think of them as Lego bricks.
Snap about 2 to 50 of those bricks into a chain and you get a peptide. Keep going past about 50 and the chain folds into a bigger shape called a protein.
Most peptides in your body work as messengers. They carry short, specific instructions from one place to another: "you are full", "release growth hormone", "start repairing here". Oxytocin, the bonding hormone, is a peptide just 9 amino acids long.
Because your stomach digests peptides like food, most peptide medicines are injected or sprayed in the nose rather than swallowed.
Why now
Why is everyone talking about peptides?
Peptides have been used in medicine for a century, since insulin in the 1920s. Four things pushed them into the mainstream.
The GLP-1 effect
Semaglutide and tirzepatide, both peptides, produced weight loss of 15 to 20% in large trials. That success made people curious about every other peptide.
Rules are loosening
In February 2026, HHS announced plans to let licensed compounding pharmacies make about 14 popular peptides, like BPC-157, with a prescription. The FDA reviewed several of them in July 2026.
Podcasts and social media
Athletes, biohackers and longevity influencers talk about peptides for healing, sleep and aging, often well ahead of the research.
They are targeted
Each peptide flips a specific switch in the body. That precision is appealing compared with broad supplements, but it also means effects can be strong.
Reading the research
How strong is the evidence?
Every peptide here gets one of three grades. Each finding is also tagged by where it was seen: in people, in animals, or in a lab dish. Results in rats often do not carry over to people.
An FDA-approved prescription medicine, backed by large human trials.
Tested in people, but in small or limited studies.
Mostly animal or lab studies. Very little data in people.
The library
Look up a peptide
5-Amino-1MQ
NNMT inhibitor (not a peptide)
A small molecule that blocks an enzyme called NNMT, which is more active in fat cells. It shrank fat in mice but has not been tested in people.
Vials: 10 mg · Capsules: 50 mg
What studies show →AOD-9604
HGH fragment 176-191
A piece of growth hormone once developed as a fat-loss drug. In people, it did not beat placebo.
Vials: 5 mg, 10 mg · Capsules: 500 mcg
What studies show →ARA-290
Cibinetide
A small peptide based on EPO, the red blood cell hormone. It keeps EPO’s tissue-protecting effect without raising red blood cells. Studied for nerve…
Vials: 5 mg, 10 mg, 15 mg
What studies show →BPC-157
Body Protection Compound 157
The most talked-about "healing peptide". It helped injuries heal faster in rats, but it has barely been tested in people.
Vials: 5 mg, 10 mg, 15 mg · Capsules: 500 mcg
What studies show →Cagrilintide
Long-acting amylin analog; half of CagriSema
A lab-made copy of amylin, a fullness hormone released with insulin. It is being tested alone and paired with semaglutide as "CagriSema".
Vials: 5 mg, 10 mg
What studies show →CJC-1295
With or without DAC; Mod GRF(1-29), often paired with ipamorelin
A lab-made signal that nudges your body to release more growth hormone for days at a time.
Vials: With DAC: 2 mg, 5 mg, No DAC: 2 mg, 5 mg, 10 mg
What studies show →Collagen peptides
Hydrolyzed collagen
The peptide most people already take. It is collagen broken into small pieces so it mixes into drinks.
What studies show →Dihexa
PNB-0408
An experimental compound that boosted memory and brain connections in rats. It has never been tested in people, and its mechanism raises safety…
Vials: 10 mg
What studies show →DSIP
Delta sleep-inducing peptide, emideltide
A peptide first found in sleeping rabbits in the 1970s and named for deep sleep.
Vials: 5 mg
What studies show →Epitalon
Epithalon, AEDG
A four-building-block peptide famous in anti-aging circles for its effect on telomeres, the caps on your DNA.
Vials: 10 mg, 20 mg, 30 mg, 35 mg, 50 mg
What studies show →GHK-Cu
Copper peptide
A tiny copper-carrying peptide found in your blood. In skin creams, it has real human data for firmer, smoother skin.
Vials: 50 mg, 100 mg · Capsules: 2 mg
What studies show →GHRP-2
Pralmorelin
A growth hormone releasing peptide that mimics ghrelin, the hunger hormone, to trigger a strong pulse of your own growth hormone.
Vials: 5 mg, 10 mg
What studies show →GHRP-6
Growth hormone releasing hexapeptide
One of the first growth hormone releasing peptides. It triggers growth hormone and is known for causing strong hunger.
Vials: 5 mg, 10 mg
What studies show →Glutathione
GSH
Your body’s main built-in antioxidant, a tiny three-amino-acid peptide. Popular for "detox", energy and skin brightening.
Vials: 1,500 mg
What studies show →HCG
Human chorionic gonadotropin, Pregnyl, Novarel
A pregnancy hormone that also tells the testes to make testosterone. It is an approved prescription for fertility and some hormone problems.
Vials: 5,000 IU
What studies show →IGF-1 LR3
Long R3 IGF-1
A modified, longer-lasting version of IGF-1, the growth factor that growth hormone tells the liver to make. Built for lab cell culture, not people.
Vials: 1 mg
What studies show →Ipamorelin
GH secretagogue
A tiny peptide that copies the "hunger hormone" ghrelin to trigger a pulse of growth hormone.
Vials: 5 mg, 10 mg
What studies show →Kisspeptin
Kisspeptin-10
The master switch for reproductive hormones, now being studied for fertility and desire.
Vials: 5 mg, 10 mg
What studies show →KPV
Alpha-MSH fragment
A three-building-block peptide studied for calming gut and skin inflammation.
Vials: 5 mg, 10 mg · Capsules: 500 mcg
What studies show →Liraglutide
Saxenda, Victoza
The first-generation daily GLP-1 medicine. It works like semaglutide but is shorter-acting and produces less weight loss.
Vials: 10 mg, 20 mg
What studies show →LL-37
Cathelicidin, CAP-18
Your body’s own germ-fighting peptide, made by skin and immune cells. It is studied for infections and slow-healing wounds.
Vials: 5 mg
What studies show →Melanotan 1
Afamelanotide, Scenesse
A lab-made copy of the hormone that makes your skin tan. An implant version is approved for a rare disease that makes sunlight painful.
Vials: 10 mg
What studies show →Melanotan 2
MT-II
An unapproved tanning peptide that also affects appetite and sex drive. PT-141 was developed from it.
Vials: 10 mg
What studies show →MGF
Mechano growth factor, IGF-1Ec
A piece of an IGF-1 variant that muscles make after being stretched or damaged. It is studied for muscle repair, mostly in animals and lab dishes.
Vials: 2 mg
What studies show →MOTS-c
Mitochondrial peptide
A peptide made by your mitochondria, the power plants in your cells, that acts a bit like exercise in a molecule.
Vials: 10 mg
What studies show →NAD+
Nicotinamide adenine dinucleotide (not a peptide)
A molecule every cell uses to make energy and repair DNA. Levels drop with age, which made it a centerpiece of longevity research. It is not a…
Vials: 500 mg, 1,000 mg
What studies show →Oxytocin
Pitocin, "the bonding hormone"
A nine-amino-acid hormone involved in bonding, trust and childbirth. Approved to start labor, and studied as a nasal spray for social connection and…
Vials: 2 mg, 10 mg
What studies show →PEG-MGF
Pegylated mechano growth factor
MGF with a polymer called PEG attached so it lasts longer in the body. The evidence is the same thin animal and lab data as MGF.
Vials: 2 mg, 5 mg
What studies show →Pinealon
EDR peptide, bioregulator
A three-amino-acid "bioregulator" from the same Russian research group as Epitalon. Studied for protecting brain cells, mostly in the lab.
Vials: 10 mg
What studies show →PT-141
Bremelanotide, Vyleesi
A prescription peptide for low sexual desire that works on the brain, not blood flow.
Vials: 10 mg
What studies show →Retatrutide
"GLP-3", triple agonist
An experimental weight-loss drug that copies three hormones at once. It has produced the largest weight loss seen so far in trials, but it is not…
Vials: 5 mg, 10 mg, 15 mg, 20 mg, 30 mg, 60 mg
What studies show →Selank
Tuftsin analog
A calming nasal spray peptide from Russia studied for anxiety without drowsiness.
Vials: 5 mg, 10 mg, 20 mg
What studies show →Semaglutide
Ozempic, Wegovy, Rybelsus
A lab-made copy of a gut hormone called GLP-1 that tells your brain you are full. It is the active ingredient in Ozempic and Wegovy.
Vials: 5 mg, 10 mg, 15 mg, 20 mg, 30 mg
What studies show →Semax
ACTH(4-10) analog
A nasal spray peptide from Russia used for focus and stroke recovery.
Vials: 5 mg, 10 mg, 20 mg
What studies show →Sermorelin
GRF(1-29)
The first 29 building blocks of the body’s own growth-hormone signal. It was once an FDA-approved drug for children.
Vials: 5 mg · Capsules: 500 mcg
What studies show →SLU-PP-332
"Exercise mimetic", ERR agonist (not a peptide)
A lab compound nicknamed an "exercise pill". In mice it switched on some of the same muscle genes as exercise. It has never been tested in people.
Capsules: 500 mcg
What studies show →SNAP-8
Acetyl octapeptide-3
A cosmetic peptide used in creams to soften expression lines. Sometimes called "topical Botox", though it is far weaker.
Vials: 10 mg
What studies show →SS-31
Elamipretide, Forzinity
A mitochondria-protecting peptide that became the first approved treatment for a rare genetic disease in 2025.
Vials: 10 mg, 25 mg, 30 mg, 50 mg
What studies show →TB-500
Thymosin beta-4 fragment
A lab-made piece of a natural repair protein. It is often paired with BPC-157 for injuries.
Vials: 5 mg, 10 mg · Capsules: 500 mcg
What studies show →Tesamorelin
Egrifta
A prescription peptide that tells your body to make more of its own growth hormone. It is approved to shrink deep belly fat in one specific group of…
Vials: 5 mg, 10 mg
What studies show →Tesofensine
Triple reuptake inhibitor (not a peptide)
An oral appetite suppressant that works on brain chemicals like dopamine and norepinephrine. It is a small-molecule drug, not a peptide.
Capsules: 500 mcg
What studies show →Thymalin
Thymulin-related thymus peptides
A mix of small peptides from the thymus, the gland that trains immune cells. It has been used in Russia for decades to support immunity.
Vials: 10 mg
What studies show →Thymosin alpha-1
Tα1, Zadaxin
An immune-boosting peptide from the thymus gland, approved in dozens of countries but not the US.
Vials: 5 mg, 10 mg · Capsules: 500 mcg
What studies show →Tirzepatide
Mounjaro, Zepbound
A weight-loss medicine that copies two fullness hormones at once, GLP-1 and GIP. People sometimes call it a "GLP-2", but that name really belongs to…
Vials: 5 mg, 10 mg, 15 mg, 20 mg, 30 mg, 60 mg
What studies show →No peptides match that. Try a different name or goal.
Blends
Peptide blends, explained
A blend is two or more peptides mixed in one vial. The research is almost always on each peptide on its own, so read each part below. Combinations are rarely studied as a pair.
BPC-157 + TB-500
5/5 mg, 10/10 mg vials · 500/500 mcg capsules
The most common healing pair. BPC-157 is studied for tendon, ligament and gut repair; TB-500 for cell movement and tissue repair. Both are mostly animal research.
Ask Mark about this blend →Wolverine
10/10 mg vial
A nickname for the BPC-157 and TB-500 healing pair in one vial.
Ask Mark about this blend →BPC-157 + KPV
500/500 mcg capsules
A gut-focused pair. Both have been studied, mostly in animals, for calming inflammation in the gut lining.
Ask Mark about this blend →GLOW
50/10/10 mg, 70/10/10 mg vials
Copper peptide GHK-Cu, the skin and collagen peptide, with the BPC-157 and TB-500 repair pair.
Ask Mark about this blend →KLOW
50/10/10/10 mg vial
GLOW plus KPV, a small anti-inflammatory peptide. Popular for skin and gut, with almost all research in animals or lab dishes.
Ask Mark about this blend →CJC-1295 (no DAC) + Ipamorelin
5/5 mg vial
The classic growth hormone pair. One mimics the brain signal GHRH, the other the hunger hormone ghrelin, and together they prompt a stronger natural growth hormone pulse.
Ask Mark about this blend →Tesamorelin + Ipamorelin
10/5 mg vial
Pairs the one FDA-approved GHRH peptide with ipamorelin to raise your own growth hormone. Tesamorelin has human data for deep belly fat.
Ask Mark about this blend →Selank + Semax
5/5 mg vial
Two Russian-developed nasal peptides: Semax for focus, Selank for calm. Human data is small and mostly from Russia.
Ask Mark about this blend →CagriSema
5/5 mg, 10/10 mg vials
Cagrilintide (an amylin copy) with semaglutide (a GLP-1). In a large trial people lost about 20% of their body weight. Still investigational.
Ask Mark about this blend →Semaglutide + BPC-157
5 mg/650 mcg, 30/3.5 mg vials
Semaglutide with a small amount of BPC-157. Often marketed for gut comfort on GLP-1s, but the combination itself has not been studied.
Ask Mark about this blend →Tirzepatide + BPC-157
30/1.3 mg, 60/2.6 mg vials
Tirzepatide with a small amount of BPC-157. Like the semaglutide version, the combination has not been studied as a pair.
Ask Mark about this blend →Questions
Peptide FAQ
What is a peptide in simple terms?
A peptide is a short chain of amino acids, the same building blocks that make up protein. Most peptides are 2 to 50 amino acids long. Your body uses them as messengers that tell cells what to do, like "you are full" or "release growth hormone".
What is the difference between a peptide and a protein?
Length. Chains of about 2 to 50 amino acids are usually called peptides. Longer chains that fold into complex shapes are called proteins.
Are peptides steroids?
No. Steroids like testosterone are built from cholesterol and have a ring-shaped structure. Peptides are chains of amino acids and work by switching on specific receptors.
Are peptides legal?
It depends on the peptide. Some, like semaglutide and tirzepatide, are FDA-approved prescription drugs. Collagen peptides are sold as supplements. Many others are not approved for human use. In 2026, HHS announced plans to let licensed compounding pharmacies make about 14 of them with a prescription, and the FDA is still reviewing several. Rules are changing, so check current status.
Are peptides safe?
Approved peptides have large safety studies behind them. Many popular peptides have only been tested in animals, so their long-term safety in people is unknown. Products bought online as "research chemicals" are not quality-controlled and may not contain what the label says.
Why do most peptides need to be injected?
Your stomach digests peptides the same way it digests food protein, breaking them apart before they can work. That is why most are injected or used as nasal sprays. A few, like oral semaglutide, are specially designed to survive digestion.
Are peptides banned in sports?
Many are. The World Anti-Doping Agency bans growth hormone releasing peptides, BPC-157, TB-500 and others. Athletes who are tested should check the current WADA list before using anything.
Not sure where to start?
Answer 8 quick questions and see which peptides the research points to for your goal.
This page explains published research in plain language. It is not medical advice, a diagnosis, or a recommendation to take anything, and it does not give dosing. Most peptides here are not FDA-approved, and products sold online vary widely in purity. Rules around peptides are changing, so check the current status and talk with a licensed clinician before starting anything. Last reviewed 2026-10-19.