Peptide reference · Updated October 31, 2026
Research peptides, explained plainly and measured precisely.
Clear briefs on 34 compounds and 8 common blends: what each one is, how it is thought to work, what the research actually shows and where it stands with regulators. Plus a reconstitution calculator that turns any vial into syringe units.
Reconstitution in three numbers
Peptide library
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Each brief follows the same structure, so you can compare compounds side by side.
Metabolic and incretin
- RetatrutideOnce-weekly triple agonist of the GIP, GLP-1 and glucagon receptors
- TirzepatideDual GIP and GLP-1 receptor agonist, approved for type 2 diabetes and obesity
- MOTS-cMitochondria-encoded peptide studied for metabolism and exercise capacity
- SLU-PP-332Synthetic estrogen-related receptor agonist studied as an exercise mimetic in mice
- 5-Amino-1MQNNMT enzyme inhibitor studied for fat metabolism in mice
- CagrilintideOnce-weekly amylin analogue studied for weight loss, alone and with semaglutide
- TesofensineTriple monoamine reuptake inhibitor studied for appetite and weight loss
- CBL-514Injectable small molecule in phase 3 trials for reducing local fat
Tissue repair and recovery
- BPC-157Gastric-protein fragment studied for tendon, gut and soft-tissue healing in animals
- TB-500Synthetic version of the actin-binding region of thymosin beta-4
- KPVThree-amino-acid fragment of alpha-MSH studied for gut inflammation
- GHK-CuCopper-binding tripeptide from human plasma, widely used in skincare
- ARA-290Erythropoietin-derived peptide that targets tissue repair without raising red cells
Growth hormone axis
- IpamorelinSelective growth hormone secretagogue acting on the ghrelin receptor
- CJC-1295 without DACStabilized short-acting analog of growth hormone releasing hormone
- SermorelinThe first 29 amino acids of natural GHRH
- TesamorelinFull-length GHRH analog approved to reduce abdominal fat in HIV lipodystrophy
- MK-677Oral, non-peptide ghrelin-receptor agonist that raises growth hormone and IGF-1
Mitochondrial and cellular
- SS-31Mitochondria-targeted tetrapeptide, approved for Barth syndrome
- NAD+Essential coenzyme for energy metabolism and DNA repair
- GlutathioneThe body's main intracellular antioxidant
Neuro and sleep
- SemaxACTH-derived peptide registered in Russia for stroke and cognitive disorders
- SelankTuftsin-derived peptide registered in Russia as an anti-anxiety agent
- DSIPNine-amino-acid peptide first isolated from sleeping rabbits
- DihexaAngiotensin IV analog studied in rats for memory and new synapse formation
Longevity and immune
- EpithalonSynthetic tetrapeptide based on a pineal gland extract
- Thymosin Alpha-1Thymus-derived immune peptide approved in many countries outside the US
Melanocortin and reproductive
- Melanotan 1Alpha-MSH analog approved as an implant for a light-sensitivity disorder
- Melanotan 2Cyclic, non-selective melanocortin agonist with no approved use
- PT-141Melanocortin agonist approved for low sexual desire in premenopausal women
- KisspeptinHypothalamic peptide that switches on the reproductive hormone axis
Nutrients and cofactors
- Vitamin B12Essential vitamin for nerve function and red blood cell production
- L-CarnitineNutrient that shuttles fatty acids into mitochondria
- MIC + B12Lipotropic nutrient mix often paired with vitamin B12
Blends
- BPC-157 + TB-500Two repair peptides combined in one vial
- GlowRepair blend with the copper peptide GHK-Cu added
- KLOWFour-part blend that adds the anti-inflammatory tripeptide KPV to Glow
- CJC-1295 (no DAC) + IpamorelinGHRH analog paired with a ghrelin-receptor agonist
- Tesamorelin + IpamorelinFull-length GHRH analog paired with ipamorelin
- Selank + SemaxTwo Russian-developed neuropeptides combined in one vial
- Super Human BlendLiquid blend of L-carnitine and eight amino acids
- Super ShredLiquid blend of L-carnitine, MIC, ATP, B12 and the asthma drug albuterol
Basics
How peptides work
A peptide is a short chain of amino acids. Your body makes thousands of them, and many act as messengers: a peptide hormone binds a matching receptor on a cell and switches on a specific pathway, such as insulin release, appetite signaling or growth hormone secretion.
Synthetic peptides copy or modify these natural messengers. Swapping one amino acid, adding a fatty-acid tail or closing the chain into a ring can make a peptide last longer, resist enzymes or favor one receptor over another. That is how short-lived natural hormones became once-weekly medicines like tirzepatide.
- Amino acid
- One of the 20 building blocks of proteins. Peptides are short chains of them, usually 2 to 50.
- Residue
- A single amino acid within a peptide chain. A 15-residue peptide has 15 amino acids.
- Lyophilized
- Freeze-dried. Most research peptides ship as a dry powder because they are far more stable that way.
- Reconstitution
- Adding a measured volume of liquid to dissolve a lyophilized powder into a solution of known strength.
- Bacteriostatic water
- Sterile water with 0.9% benzyl alcohol, a preservative that slows bacterial growth in multi-use vials.
- Concentration
- How much compound is in each mL of solution, written here in mcg/mL.
- U-100 syringe
- An insulin-style syringe marked in units where 100 units equal 1 mL, so 1 unit is 0.01 mL.
- Agonist
- A molecule that activates a receptor. Tirzepatide is a GIP and GLP-1 receptor agonist.
- Secretagogue
- A compound that makes a gland release a hormone it already produces, such as growth hormone.
- Half-life
- The time it takes for half of a compound to be cleared from the blood.
- HPLC purity
- The share of the sample that is the target peptide, measured by high-performance liquid chromatography.
- Net peptide content
- The weight of actual peptide in a vial after subtracting water and salt counter-ions. It is often 70 to 90% of the gross weight.
Regulation
Where the rules stand in late 2026
A handful of peptides are FDA-approved drugs for specific uses. Most others are research chemicals. In July 2026 an FDA advisory committee recommended six for pharmacy compounding, and on October 28 HHS said it will allow 503A pharmacies to compound those six under strict interim conditions. None of them is an approved drug.
| Compound | Status | Detail |
|---|---|---|
| Tirzepatide | FDA-approved drug | Mounjaro (type 2 diabetes, 2022) and Zepbound (weight management, 2023) |
| Tesamorelin | FDA-approved drug | Egrifta, abdominal fat in HIV lipodystrophy (2010) |
| PT-141 | FDA-approved drug | Vyleesi, low sexual desire in premenopausal women (2019) |
| Melanotan 1 | FDA-approved drug | Scenesse implant, erythropoietic protoporphyria (2019) |
| SS-31 | FDA-approved drug | Forzinity, Barth syndrome, accelerated approval (2025) |
| Retatrutide | Investigational drug | Phase 3 complete in obesity; filing planned for early 2027 |
| BPC-157 | 503A compounding under interim HHS policy | Panel voted 8 to 6 in favor (July); HHS interim 503A policy (Oct 28, 2026) |
| TB-500 | 503A compounding under interim HHS policy | Panel voted 8 to 6 in favor (July); HHS interim 503A policy (Oct 28, 2026) |
| KPV | 503A compounding under interim HHS policy | Panel voted 8 to 6 in favor (July); HHS interim 503A policy (Oct 28, 2026) |
| MOTS-c | 503A compounding under interim HHS policy | Panel voted 7 to 5 in favor (July); HHS interim 503A policy (Oct 28, 2026) |
| Semax | 503A compounding under interim HHS policy | Panel voted in favor (July); HHS interim 503A policy (Oct 28, 2026); registered in Russia |
| Epithalon | 503A compounding under interim HHS policy | Panel voted in favor (July); HHS interim 503A policy (Oct 28, 2026) |
| DSIP | Research use only | Panel voted 7 to 6 against (July 2026); not in the HHS policy |
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Common questions
Before you start reading
What does "research use only" mean?
It means a product is sold for laboratory, in vitro or analytical work and not for use in people or animals. Research-grade material is not made under drug manufacturing rules and has not been evaluated by the FDA for safety, quality or effectiveness in humans. A research-grade vial of a compound is not the same product as an approved medicine with the same name.
Are peptides legal in the United States?
It depends on the peptide and how it is sold. Some, such as tirzepatide, tesamorelin and bremelanotide, are FDA-approved prescription drugs. Others can only be sold as research chemicals. Compounding pharmacies may use a bulk substance only if it meets FDA requirements, and in 2023 the FDA flagged many popular research peptides, including BPC-157, as raising potential safety concerns for compounding.
On October 28, 2026, HHS announced an interim policy under which it does not intend to act against 503A pharmacies, federal facilities and licensed physicians that compound six peptides (BPC-157, Epithalon, KPV, MOTS-c, Semax and TB-500) under strict conditions. It does not approve any product, does not add the six to the bulks list, and does not change the status of research-grade material.
This page describes the situation as of October 31, 2026 and is not legal advice.
What happened at the July 2026 FDA advisory committee meeting?
On July 23 and 24, 2026 the FDA's Pharmacy Compounding Advisory Committee reviewed seven peptides. It voted to recommend six for the list of bulk substances that pharmacies may compound: BPC-157, KPV and TB-500 (each 8 to 6), MOTS-c (7 to 5), Semax and Epithalon. It voted 7 to 6 against DSIP (emideltide).
The votes were advisory, and FDA staff had recommended against all seven. On October 28, 2026, HHS responded with an interim enforcement discretion policy for the six recommended peptides, limited to 503A compounding under strict conditions. Adding any of them to the bulks list would still take formal rulemaking. DSIP is not covered.