All Peptides List and What They Do

Peptides are short chains of amino acids — usually fewer than 50 — that act as signaling molecules, and the full peptides list runs from FDA-approved drugs like insulin and semaglutide to unapproved research compounds like BPC-157 and TB-500. What a given peptide does depends on which receptors it binds, so effects range from controlling blood sugar and hormone release to supporting skin, immune defense, and tissue repair.

What Counts as a Peptide?

A peptide is a chain of amino acids joined by peptide bonds. The line between a peptide and a protein is a matter of convention rather than biology: most scientists call chains under about 50 amino acids peptides and longer chains proteins.

Because they are small, peptides can be synthesized in a lab and delivered by injection, nasal spray, or topical cream. That is why the same word covers a prescription diabetes medication, an anti-wrinkle serum, and a vial labeled 'for research use only.'

Peptide Categories at a Glance

Grouping peptides by what they target is the fastest way to make sense of the list. The table below covers the categories most people mean when they look for a reference on all peptides and their functions.

Category	How It Works	Common Examples	Typical Use
GLP-1 and incretin mimetics	Mimic gut hormones that slow digestion and increase fullness	Semaglutide, tirzepatide, liraglutide	FDA-approved for type 2 diabetes and weight management
Growth hormone secretagogues	Signal the pituitary to release more growth hormone	CJC-1295, ipamorelin, sermorelin, tesamorelin, GHRP-6	Tesamorelin is FDA-approved for HIV-related lipodystrophy; the rest are research-only
Tissue-repair peptides	Studied for blood vessel growth, cell migration, and repair	BPC-157, TB-500	Not FDA-approved for human use
Cosmetic peptides	Support collagen production or relax surface tension in skin	GHK-Cu, matrixyl, argireline	Topical skincare products
Metabolic and endocrine peptides	Act as hormones that regulate glucose, water balance, or reproduction	Insulin, glucagon, oxytocin, desmopressin	Prescription medications
Antimicrobial peptides	Disrupt microbial membranes and modulate immune response	LL-37, defensins, magainin	Research and early clinical trials
Dietary collagen peptides	Provide amino acids and short collagen fragments	Collagen hydrolysate, marine collagen	Food and supplement products

Common Peptides and What They Do

Hormone and metabolic peptides

• Insulin lowers blood glucose and is FDA-approved for diabetes.
• Semaglutide (Ozempic, Wegovy) is a GLP-1 receptor agonist approved for type 2 diabetes and chronic weight management.
• Tirzepatide (Mounjaro, Zepbound) is a dual GIP/GLP-1 agonist approved for diabetes and weight loss.
• Glucagon raises blood glucose and is used to treat severe hypoglycemia.
• Desmopressin is a synthetic vasopressin analog used for diabetes insipidus and nocturnal bedwetting.
• Oxytocin is approved for inducing labor and is studied for social behavior.

Growth hormone-related peptides

• Tesamorelin (Egrifta) is the only growth hormone-releasing peptide with FDA approval, for HIV-associated fat accumulation.
• Sermorelin was previously approved for diagnostic use in children.
• CJC-1295, ipamorelin, GHRP-2, GHRP-6, and hexarelin are sold as research chemicals and are not approved for human use.
• Bremelanotide (PT-141) is a melanocortin agonist approved for hypoactive sexual desire disorder in premenopausal women.

Repair and cosmetic peptides

• BPC-157 is studied in rodents for tendon, ligament, and gut healing; BPC-157 is not FDA-approved for human use in the United States.
• TB-500 (a thymosin beta-4 fragment) is researched for cell migration and repair and is banned in sport by WADA.
• GHK-Cu, matrixyl, and argireline appear in topical anti-aging products, where evidence for visible wrinkle reduction is modest.

Peptides for Bodybuilding, Muscle Growth, and Fat Loss

Anyone hunting for all types of peptides for bodybuilding will keep seeing the same names: ipamorelin, CJC-1295, tesamorelin, GHRP-2, GHRP-6, and hexarelin. These are growth hormone secretagogues, which means they prompt the pituitary gland to release more growth hormone.

The question 'do peptides work for muscle growth' has a nuanced answer. Restoring growth hormone in someone who is deficient can increase lean mass, but trials in healthy, trained adults have not shown that secretagogues reliably add muscle beyond what resistance training and adequate protein already do.

Discussions about peptides for muscle growth and fat loss reddit often blur evidence with anecdote. The clearest clinically measured results belong to GLP-1 medications such as semaglutide and tirzepatide, which produce meaningful weight loss by reducing appetite, with gastrointestinal side effects that require medical oversight.

Antimicrobial Peptides and All Natural Peptides

All natural peptides in the human body include hormones such as insulin and oxytocin, immune molecules such as defensins, and digestive signals such as gastrin. Because peptidases break them down quickly, many must be injected or chemically modified to last long enough to work.

Antimicrobial peptides are part of innate immunity: they puncture bacterial membranes, attract immune cells, and fine-tune inflammation. In coursework, exam items like 'antimicrobial peptides can do all of the following except' test whether students can separate membrane disruption from hormone signaling.

How to Read a Peptide List Without Getting Misled

Searching for all peptides and what they do reddit surfaces threads that mix prescription drugs, veterinary products, and gray-market vials into one long list. A more useful filter is to check three things: FDA approval status, whether human trials exist, and who is selling the product.

A good all peptides list and what they do reference states the approval status next to every entry, because the difference between a monitored prescription and an unregulated vial is the part that matters most.

Safety, Legal Status, and Before You Start

Legality depends on the compound. Peptides without FDA approval are often sold as 'research chemicals' or 'not for human consumption,' which shifts risk to the buyer and leaves no guarantee of purity or dose accuracy.

• Prescription peptides such as semaglutide, tesamorelin, and insulin require a licensed clinician.
• Unapproved peptides such as BPC-157, TB-500, and melanotan II have no verified human safety profile and carry contamination and immune-reaction risks.
• Collagen and cosmetic peptides are regulated as food or cosmetics, not drugs, so they cannot legally claim to treat disease.

Reported side effects of peptide use include injection-site reactions, nausea, headache, water retention, and hormonal changes. Anyone considering a peptide for a health or performance goal should discuss it with a healthcare professional first.

COMMON QUESTIONS

Frequently Asked Questions

Are peptides safe?

Safety depends entirely on the specific peptide. FDA-approved peptides such as insulin, semaglutide, and tesamorelin have documented safety profiles when prescribed and monitored by a clinician. Unapproved compounds like BPC-157 and TB-500 have limited human data, and vials sold online may contain impurities or the wrong dose.

Are peptides legal to buy in the US?

Prescription peptides require a doctor's order and cannot legally be sold as dietary supplements. Many unapproved peptides are marketed as 'research chemicals' or 'not for human consumption,' which does not make them legal for personal use. Buying them for injection is a legal gray area and carries real health risk.

Do peptides actually work for muscle growth?

Growth hormone secretagogues can raise growth hormone and IGF-1 levels, but studies in healthy, trained adults have not shown reliable muscle gains. GLP-1 medications produce measurable weight loss by reducing appetite, not by building muscle. Resistance training and adequate protein remain the best-supported approach.