Peptide Reference DeskEducational reference · not medical advice
Educational reference · United States · current to September 2026

Research peptides, explained plainly.

What they are, what the law actually says, how to judge the science, what is really in a vial, and how laboratories handle these materials. Every compound gets an evidence tier and a one-line bottom line, with the primary source linked next to each claim.

43Compounds indexed
71Primary sources linked
A–DEvidence tiers
Sep 27Last reviewed, 2026

This site describes what has been studied, as history, not as guidance. It contains no dosing, administration, or protocol information and is not medical advice. Most compounds here have never been shown safe or effective in humans for the purposes they are marketed for. Regulatory details change often; re-check the primary source linked before relying on anything.

Version 1.0 · compiled September 25, 2026 · reviewed September 27, 2026 Reference only · sells nothing · links to no products
← All sections/01 · Basics
01 · Basics

What a “research peptide” is

Peptides in one paragraph

A peptide is a short chain of amino acids, the same building blocks that make up proteins. The dividing line is fuzzy, but chemists generally call a chain of up to about 50 amino acids a peptide and anything longer a protein. Your body makes thousands of them: insulin is a peptide, so are oxytocin, the gut hormone GLP-1, and the antimicrobial peptides in your skin. Because they are made of natural building blocks, peptides tend to be broken down quickly by the body's enzymes, which is why many are unstable, why most can't be taken as ordinary pills, and why pharmaceutical companies spend years modifying them (adding fatty-acid tails, swapping amino acids, capping the ends) to make a version that lasts long enough to be a drug. Semaglutide, the active ingredient in Ozempic and Wegovy, is exactly that: a natural gut hormone re-engineered to survive in the body for a week instead of a couple of minutes.

What “research use only” actually means

Chemical suppliers have sold reagents labeled “for research use only” (RUO) for decades. In that world, the label means what it says: the material is made for laboratory work (cell cultures, animal studies, assay development) and is not made, tested, or intended for use in people. Legitimate research-grade peptides from suppliers like Bachem, GenScript, or Sigma-Aldrich are quality-controlled for identity and purity, but not for sterility, endotoxins, or safety in a human, because none of that matters in a test tube.

Over the last decade a very different market grew up around the same label. Online vendors sell lyophilized (freeze-dried) peptides in vials, marked “research use only / not for human consumption,” to a customer base that is overwhelmingly not running laboratories. This is what people usually mean by “research peptides,” and it is important to understand how regulators see it: the label does not decide what a product legally is. The intent behind selling it does. That is the subject of the next section.

The three questions this reference asks of every compound

  1. What is it, and what has it actually been studied for? Not what a vendor says it does; what the published literature has examined, and in what (a dish, an animal, or a human).
  2. What is its legal and regulatory status? Approved drug, investigational, never approved, subject to specific FDA action, banned in sport.
  3. What safety signals exist? Both the ones from the science and the ones from the marketplace (contamination, mislabeling, wrong identity).
← All sections/Tool · Calculator
Tool · Calculator

Stock solution calculator

Laboratory concentration arithmetic: mass ÷ volume, corrected for what the certificate of analysis actually says. The same kind of calculator peptide manufacturers publish for bench work.

Enter what the label and the certificate of analysis say; it returns the real concentration of correct-sequence peptide in the stock solution, and the volume needed to hit a target concentration. It is a concentration calculator for bench work, the same kind manufacturers publish; it does not and will not compute doses.

Concentration from label and COA

mass ÷ volume, corrected
Nominal concentration—
Correct-sequence peptide in vial—
Actual concentration—
Molar concentration—
Enter a target to see the solvent volume that gives it, using the corrected mass.

Why the correction matters: "5 mg, 99% pure" describes two different things. Purity is the share of the peptide material that is the right sequence; peptide content is the share of the powder that is peptide at all rather than water and counter-ions (typically 70–90% for research peptides). If the COA does not report peptide content, the "actual" figure here is an upper bound. Research labs confirm concentration by UV absorbance or amino acid analysis rather than trusting label mass.

How to read the result

Nominal concentration is what the label implies: labeled milligrams divided by the volume you add. Correct-sequence peptide in vial applies the COA's HPLC purity (the share of peptide material that is the right sequence) and peptide content (the share of the powder that is peptide rather than water and counter-ions). Actual concentration is that corrected mass divided by the volume, and is the number a laboratory would label the stock with. Molar concentration needs the molecular weight from the COA or the supplier's page.

If the COA reports purity but not peptide content, leave content blank and treat the result as an upper bound; Bachem's published range for research peptides is 70–90% content, so the real figure is usually 10–30% lower. Labs confirm by UV absorbance or amino acid analysis rather than trusting label mass. See What is actually in the vial for how to read a COA, and Laboratory handling for solvents, storage, and technique.

This tool computes concentrations of laboratory stock solutions. It does not compute doses, and nothing on this site describes using these materials in people.

← All sections/02 · Regulation
02 · Regulation

The law, in plain English

United States, as of September 2026. This is general legal information, not legal advice.

The one rule that explains everything: intended use

Under the federal Food, Drug, and Cosmetic Act, something is a drug if it is intended to treat or prevent disease or to affect the structure or function of the body. A new drug cannot be sold in interstate commerce without FDA approval. Whether a product is “intended” for human use is judged by what the FDA calls intended use (21 CFR 201.128): the objective intent shown by labeling, advertising, website content, the way the product is designed and packaged, and the circumstances of its sale. A “research use only” sticker is one piece of evidence; a page describing weight-loss results, a dosing calculator, or a bundle that ships with bacteriostatic water and syringes is other evidence, and it outweighs the sticker.

That is not a theory. In every peptide warning letter the FDA issued in 2025 and 2026, the agency used the same formula: despite statements on the labeling that the products are for research use only and not for human consumption, evidence from the website establishes that the products are intended as drugs for human use. Examples: USApeptide.com (Feb 2025); five vendors at once, including Peak Performance Peptides (Aug 2026); law-firm analysis at ArentFox Schiff. In July 2026 the owner of Paradigm Peptides was sentenced to 70 months in federal prison for introducing unapproved new drugs with intent to defraud, after two earlier warning letters were ignored (DOJ press release).

A genuinely research-only product, sold as a laboratory reagent with reagent-style information, sits outside drug approval. The same vial, sold with claims or instructions that imply human use, is an unapproved drug, and the seller carries that risk.

Who can legally buy research peptides?

There is no federal license, prescription, or credential required to purchase a chemical that is genuinely sold for laboratory research. No research peptide in this reference is a controlled substance under the Controlled Substances Act. Sellers commonly require buyers to be adults and to attest that the purchase is for research; those are private policies, not statutory requirements.

What the FDA has actually done about peptides

Most of the “is this peptide legal?” confusion comes from one FDA process: the list of bulk drug substances that compounding pharmacies are allowed to use. Compounders (503A pharmacies making patient-specific prescriptions, and 503B outsourcing facilities) can only work from approved drugs, substances with a USP monograph, or substances FDA has placed on its approved bulks list. Substances nominated for that list are sorted into Category 1 (may be compounded while under review), Category 2 (significant safety concerns; may not be compounded), and Category 3 (nominated without enough information). Placing a peptide in Category 2 says nothing about buying it as a research chemical; it stops licensed pharmacies from compounding it into a prescription product. But because that decision comes with a written FDA safety assessment, it became the de facto public verdict on each peptide.

“Removed from Category 2” does not mean approved, endorsed, or shown safe. It means a compounding-eligibility process moved one step, over FDA staff objections, and is not finished.

State medical boards

Through 2025 and 2026, state boards began acting against licensed providers, not consumers. Ohio's Board of Pharmacy (December 2025) said “research purposes only” products are unlawful for clinics to possess. Alabama's medical board (May–June 2026) stated that under no circumstances may a physician compound, administer, or dispense a research-grade peptide to a patient. Mississippi and South Carolina medical boards are reported to have issued similar notices in August 2026, adding that a patient's signed consent does not cure the problem (reported by a law firm; the South Carolina board's primary document has not yet been located) (McDermott; Luma Lex on MS and SC). No state statute banning consumer possession of research peptides was identified.

Sport

The World Anti-Doping Agency list is updated each January and applies to Olympic sports, the NCAA through USADA, and most international federations. Section S2 prohibits peptide hormones and growth factors at all times, naming GHRH analogues (CJC-1295, sermorelin, tesamorelin), GH secretagogues (ibutamoren, ipamorelin), GH-releasing peptides (GHRP-2, GHRP-6, hexarelin), GH fragments (AOD-9604, hGH 176-191), IGF-1 and analogues, thymosin beta-4 derivatives including TB-500, and kisspeptin, plus “other substances with similar chemical structure or biological effect.” BPC-157 is prohibited under S0 (non-approved substances). GLP-1 drugs are on WADA's monitoring program, not the prohibited list. Testing operates on strict liability: what is in the sample is the athlete's responsibility, and research-grade products carry contamination risk on top of the named prohibitions (WADA Prohibited List; S2 summary). US professional leagues use their own collectively bargained lists, which overlap heavily with WADA on the GH axis.

Where the risk actually sits

For sellers: any therapeutic claim, dosing or reconstitution-for-use guidance, bundled injection supplies, testimonials, or “cycle” content can establish human intended use, which makes the product an unapproved new drug and, if directions for use are absent, misbranded. The FTC separately requires competent and reliable scientific evidence for health claims and has said plainly that disclaimers do not cure a deceptive ad (FTC health products guidance). Payment processors enforce their own rules: Stripe's restricted-business list names “incorrectly labeled research chemicals” (Stripe).

For buyers: product quality (section 04) is the everyday risk. For licensed professionals: state board discipline is now an active risk in at least four states, including South Carolina.

← All sections/03 · Science literacy
03 · Science literacy

How to read the evidence

Almost every claim about a peptide traces back to one of three kinds of study, and the gap between them is enormous.

Three kinds of study

In vitro (“in glass”). Cells in a dish exposed to the compound. Useful for mechanism; says nothing about what happens in a living body, where the compound has to survive digestion or blood enzymes, reach the right tissue, and not do something else along the way. A great deal of what is written about the “bioregulator” peptides (epitalon, pinealon, vilon) rests here.

Animal studies. Usually mice or rats, often with an injury or disease deliberately induced. These are real evidence about biology, and they are where most of the BPC-157, TB-500, and MOTS-c literature lives. Their limitation is well documented: most compounds that work in rodents fail in humans, and rodent studies rarely run long enough to detect slow harms like cancer promotion.

Human studies, in ascending order of strength: case reports (one patient), observational studies (measuring something in people who happened to use it), small uncontrolled trials, randomized placebo-controlled trials, and finally large phase 3 programs of the kind required for FDA approval. A drug like semaglutide has tens of thousands of trial participants behind it; BPC-157 has, as of a 2025 systematic review, one retrospective report of twelve patients (Vasireddi et al., HSS Journal 2025).

The evidence tiers used in the compound index

Tier AFDA-approved drug with phase 3 trial data (for a specific indication)
Tier BReal human trials, but not approved in the US (approved abroad, investigational, or tested and failed)
Tier CHuman pharmacology only (it moves a biomarker); no evidence of clinical benefit
Tier DAnimal and/or cell studies only; never tested in a controlled human trial

Three patterns to learn to spot

  1. Borrowed legitimacy. An approved relative is used to imply an unapproved compound is proven. Tesamorelin's approval is cited for CJC-1295; afamelanotide's approval is cited for melanotan II; a follistatin gene therapy trial is cited for injected follistatin protein. The relative's data do not transfer.
  2. “Tested” is not the same as “worked.” Several popular peptides were tested in humans and failed: ipamorelin missed its primary endpoint in a 114-patient trial, AOD-9604's obesity program did not show meaningful weight loss, DSIP produced decades of mixed sleep results, aviptadil was denied emergency authorization twice. Marketing usually presents these as “studied,” which is technically true.
  3. Single-source science. Much of the BPC-157 literature comes from one laboratory in Zagreb; much of the semax, selank, epitalon, and thymalin literature comes from one research tradition in Russia. That does not make it wrong, but independent replication is the thing that separates a promising result from an established one, and for these compounds it is largely missing.
← All sections/04 · Quality
04 · Quality

What is actually in the vial

Purity and content are two different numbers

A vial labeled “5 mg, 99% pure” is making two separate claims, and newcomers routinely confuse them.

Purity comes from HPLC (high-performance liquid chromatography) and describes what fraction of the peptide material is the correct sequence rather than truncated, deleted, or oxidized variants. “99%” means the main peak is 99% of the area under the chromatogram.

Peptide content (or net peptide) describes what fraction of the powder's mass is peptide at all, as opposed to water and counter-ions. Synthetic peptides come out of purification as salts, typically trifluoroacetate (TFA) or acetate, and every basic site on the chain carries one. Bachem, a major manufacturer, gives the typical range: research peptides are usually more than 95% pure by HPLC, but “the peptide content of the solid may range from 70 to 90%” (Bachem technical note). So a “5 mg, 99% pure” vial can legitimately contain around 3.5–4.5 mg of the actual peptide, and whether “5 mg” on a gray-market label means gross powder weight or net peptide is usually unstated.

How to read a certificate of analysis (COA)

A real COA reports several things, and each answers a different question (Bachem QC guide):

Line on the COAQuestion it answers
HPLC purity (area %)Is the peptide that's there the right peptide? Look for the chromatogram itself, not just a number.
Mass spectrometryDoes the measured mass match the expected mass? In electrospray MS a peptide shows up as a family of charged ions; software collapses them to a single molecular weight, which should match theory within a fraction of a dalton. MS confirms mass, not sequence order.
Peptide content / net peptideHow much of the powder is peptide (by amino acid analysis or UV absorbance). This is the number that turns label milligrams into real milligrams. Most gray-market COAs do not include it.
Water content (Karl Fischer) and counter-ionHow much of the mass is water and TFA or acetate.
Endotoxin (LAL test)Bacterial toxins that cause fever and inflammation if injected. Irrelevant for a bench assay; the single most important difference between research-grade and pharmaceutical-grade material. Purity does not predict endotoxin: a 99.8% pure peptide can carry endotoxin.
SterilityA separate microbiological test that research-grade products almost never claim.

Third-party vs in-house. A manufacturer's own COA is a self-report. Independent labs used in this space include Janoshik Analytical (purity, identity, and measured quantity vs label; reports carry a verification code checkable on the lab's site) and MZ Biolabs in Tucson, which states explicitly that its purity testing “does not test for activity, sterility/endotoxins, heavy metals, or pH” (MZ Biolabs). A third-party report covers only the sample submitted, and a vendor chooses which vial to send. Check that the lot number on the report matches the vial, that the report is recent, that quantity was measured and not just purity, and whether endotoxin was tested at all.

What testing of gray-market products has found

The common failures are content that doesn't match the label (both over and under), wrong identity, endotoxin contamination, non-delivery fraud, and unverifiable COAs.
← All sections/05 · Bench practice
05 · Bench practice

Laboratory handling

Standard reagent-handling practice from manufacturers' technical guides, applicable to any lyophilized peptide used in a laboratory. It is not administration guidance.

Why peptides are freeze-dried

Water drives most of the chemistry that degrades a peptide (hydrolysis, deamidation, oxidation), so peptides are shipped lyophilized: frozen and dried under vacuum into a powder or “cake.” In that form, stored cold and dry, most are stable for years (GenScript storage guide). Once dissolved, the clock starts.

Storage

Reconstitution (laboratory)

Reconstitution means dissolving the freeze-dried powder in a solvent to make a stock solution of known concentration.

Solvent. Manufacturer guides describe solvent choice by the peptide's chemistry (GenScript solubility guidelines): most water-soluble peptides go into sterile, preservative-free water or an appropriate buffer, with solutions used within days or frozen in aliquots; basic peptides that resist dissolving are tried in dilute acetic acid; acidic peptides in a little dilute ammonium hydroxide (never with cysteine present); neutral or very hydrophobic peptides may need a small amount of DMSO first, then dilution, with the caveat that DMSO can oxidize methionine and cysteine.

Technique. Test solubility on a tiny amount first. Add the solvent slowly down the inside wall of the vial so it runs onto the powder rather than blasting it; swirl or roll gently, never shake (foaming creates air–liquid interfaces that promote aggregation). Give it time; brief sonication is acceptable if dissolution is slow. Cloudiness or particles signal aggregation or insolubility. Label every vial and aliquot with the peptide, lot, solvent, concentration, and date.

The arithmetic. Concentration is mass divided by volume: a labeled 5 mg dissolved in 2 mL gives 2.5 mg/mL; the same 5 mg in 1 mL gives 5 mg/mL. And this is where section 04 matters: if the COA states 82% peptide content and 98.5% purity, the correct-sequence peptide in that “5 mg” vial is about 5 × 0.82 × 0.985 ≈ 4.0 mg, so the real concentration in 2 mL is about 2.0 mg/mL, not 2.5. Research labs quantify by UV absorbance or amino acid analysis rather than trusting the label mass for exactly this reason.

Calculator. This arithmetic is available as an interactive stock solution calculator, which also corrects for purity and peptide content and converts to molarity.

Basic safety

Standard laboratory practice applies: work on a clean surface, wipe vial stoppers with 70% alcohol before piercing, use a fresh sterile needle or transfer tip for each transfer, and treat used needles as sharps, which go straight into a sharps container and out through a local disposal program. DMSO, acetic acid, and ammonium hydroxide are chemical hazards in their own right, and used peptide solutions are chemical waste. Keep all materials locked away from children and pets. And keep the regulatory fact in view: products sold for research are chemical reagents, not made under pharmaceutical GMP, and not sterile or endotoxin-tested unless the COA specifically says so.

← All sections/06 · Index
06 · Index

The compounds

Forty-three peptides and peptide-adjacent products. Each entry gives what it is, what research has looked at, how strong the human evidence is, regulatory and sport status, safety signals, and a one-line bottom line. Status is as of September 2026.

AApproved drug, phase 3 data (for a specific indication)
BHuman trials, not US-approved (approved abroad, investigational, or failed)
CHuman pharmacology only; no evidence of clinical benefit
DAnimal / cell studies only
← All sections/07 · Terms
07 · Terms

Glossary

503A / 503B
Sections of the FD&C Act governing compounding. 503A: state-licensed pharmacies making patient-specific prescriptions. 503B: FDA-registered outsourcing facilities making larger batches under GMP.
Bulk drug substance
The active ingredient used in compounding; FDA keeps lists of which ones compounders may use.
Category 1 / 2 / 3
FDA's interim sorting of nominated bulk substances: may be compounded during review / significant safety risk, may not / nominated without adequate information.
COA
Certificate of Analysis, a document reporting identity, purity, and (sometimes) content, water, counter-ion, and endotoxin results for a specific lot.
Endotoxin
Bacterial cell-wall fragments that cause fever and inflammation when injected; measured by the LAL test; not predicted by purity.
GMP / CGMP
(Current) Good Manufacturing Practice, the federal manufacturing-quality regulations for drugs (21 CFR 210/211). Research chemicals are not made under them.
HPLC
High-performance liquid chromatography, the standard purity method for peptides.
IND
Investigational New Drug application, the lawful route for studying an unapproved drug in humans.
Intended use
The legal doctrine (21 CFR 201.128) that decides whether a product is a drug, based on how it is labeled, advertised, and sold.
Lyophilized
Freeze-dried.
Net peptide content
The fraction of a powder's mass that is peptide rather than water and counter-ions.
PCAC
FDA's Pharmacy Compounding Advisory Committee; its votes are advisory.
RUO
“Research use only”; a label describing intended laboratory use, legally meaningful only when the actual marketing matches.
S0 / S2 / S4
Sections of the WADA Prohibited List: non-approved substances / peptide hormones and growth factors / hormone and metabolic modulators.
TFA
Trifluoroacetic acid, the counter-ion most synthetic peptides carry after purification.
Unapproved new drug
Any drug lacking FDA approval that is sold in interstate commerce with human intended use.
← All sections/08 · Primary documents
08 · Primary documents

Sources

Regulatory dates and list memberships were compiled from FDA pages and law-firm summaries current to September 25, 2026; the FDA Category 2 page (updated April 22, 2026) was checked directly. Secondary sources sometimes lag it.

Regulators and law

Product quality and handling

Compound literature and labels

← All sections/09 · About
09 · About

Why this site exists

A note from the person who put it together.

I'm not a scientist. I fix cars for a living, mobile, out of a truck, in South Carolina. Before that I owned a repair shop until it burned down. I've got two boys, and somewhere in my forties I got serious about training and about understanding what was actually going on in my own body instead of guessing.

That's how I ended up reading about peptides. And what I found was two kinds of information and almost nothing in between. On one side, forums and sellers where every compound heals everything and nobody cites anything. On the other, FDA documents, trial papers, and law-firm memos written for people who already know what a 503A pharmacy or an endotoxin test is. If you were a regular person trying to figure out what any of this meant, what was actually studied, what the law really said, and what was even in the vial, you were on your own.

So I did the reading. Months of it. FDA's compounding lists and advisory-committee transcripts, the warning letters, the WADA list, the manufacturer handling guides, the trial papers behind the popular names, the testing studies of what's really being shipped. Then I put it in plain English, in one place, with the primary source linked next to every claim so you can check my work.

What you should know about me

I also own a company in this space that sells research-grade peptides to laboratories. I'm telling you that up front because you'd find it in two minutes anyway, and because it's the reason this site is built the way it is. Nothing here links to that company or to any product. There are no prices, no “where to buy,” no testimonials, and no advice about using any of these compounds in a person. If I ever let this site turn into a sales page, it would stop being useful to you and it would say something about me I don't want said.

What this site deliberately leaves out

Dosing, protocols, “stacks,” and anything else that treats a research chemical like a medicine. That is not caution for its own sake. Every compound in the index has a line that says how much human evidence exists, and for most of them the honest answer is little or none. Writing instructions for people to use something that has never been tested in a controlled human trial would be pretending to knowledge nobody has.

How to use it

Start with the law section if you're confused about what's legal, the evidence section if you want to get better at reading claims, and the compound index for any specific name. If you find an error, or a regulatory date that's gone stale, tell the publisher and it gets fixed. The FDA process on these compounds is moving, and this site will be updated as it does.

Publisher. Carolina Viking Merchandising LLC, South Carolina. Contact address to be added. Last reviewed September 27, 2026.