Research peptides in France: the 2026 guide

Research peptides are now everyday tools in cell biology, pharmacology and analytical chemistry. Yet in France the same questions come up with every purchase: what exactly is a research peptide, under what framework can it be bought, how do you judge the quality of a lot, and how should it be stored and put back into solution? This guide covers the essentials. For each point, it links to a more detailed article.

This guide is for information only. It is neither legal advice nor a recommendation for use. The products mentioned are intended exclusively for in vitro research, with no human or animal use of any kind.

What is a research peptide?

A peptide is a short chain of amino acids joined by peptide bonds. It usually has between 2 and about fifty residues; beyond that, it is generally called a protein. The basics are covered in What is a peptide?.

A research peptide is a laboratory reagent. It is made by chemical synthesis, most often on a solid phase (SPPS), then purified by chromatography and lyophilized. It is used for scientific work: assays on cell cultures or isolated receptors, development of analytical methods, internal standards. It is not a medicine. It has not been evaluated for any use in humans.

Many research peptides are copies or analogues of natural peptides. Some are modified to better resist the enzymes that break them down: one example is NA Selank Amidate, a stabilized form of Selank.

The synthesis method has a long history, from the peptide bond described by Emil Fischer to Bruce Merrifield's solid-phase synthesis. It is traced in Research peptides: history and science. The production steps (Fmoc synthesis, HPLC purification, lyophilization) are summarized on our manufacturing process page.

Each peptide is described by an identity sheet: sequence, molecular formula, molar mass, CAS number. Knowing how to read it is the first useful skill. See Reading a peptide data sheet.

The framework in France: "Research Use Only"

This section is for information only and is not legal advice. The framework changes over time and every situation is different: for a specific question, consult a legal professional.

Laboratory reagent or medicine

French regulations distinguish medicines, whose sale falls under the pharmaceutical monopoly and the oversight of the ANSM (the French medicines agency), from reagents intended for research. The French Public Health Code (Article L.5111-1) defines as a medicine, among other things, any product presented as having curative or preventive properties with regard to diseases. In other words, the way a product is presented matters as much as what it contains. This is why a serious supplier makes no health claims.

What the RUO label covers

The "Research Use Only" (RUO) label indicates a product intended for laboratory research, with no safety or efficacy assessment for any other use. It is not a formality: it is the promoted use that defines a product, not the label. The topic is covered in detail in "Research Use Only": what the label means.

A consistent RUO framework rests on three principles:

• no health claims, no dosing, no protocol intended for a person;
• analytical documentation of lots by a third-party laboratory;
• sales to buyers working in a research setting.

Our article The legal framework for research peptides in France covers this framework in detail.

At Peptinium Labs, sales are restricted to research professionals. The products are intended neither for resale nor for human or veterinary use.

Choosing a research peptide supplier

Price says nothing about the quality of a lot. Five verifiable criteria make it possible to compare suppliers. Most of them are developed in Traceability and third-party quality control.

HPLC purity that is measured, not just claimed

Purity is expressed as a percentage: the share of the main peak on an HPLC chromatogram. A threshold of 99% is a common reference in peptide research. The figure only carries weight if it appears on an analysis report, not just on a product page.

Identifiable analysis reports

A serious analysis report identifies the sample tested, with a date and a report number that can be checked with the laboratory. Two lots of the same peptide are never strictly identical: the more recent the report and the closer it is to the lot sold, the more it is worth.

An independent laboratory

An analysis carried out by the seller on its own product remains a self-declaration. A third-party laboratory separates the party that sells from the party that measures. In Europe, Janoshik (Czech Republic) is a reference laboratory in peptide research. Our comparison of analytical laboratories presents Janoshik, ChemRx and Colmaric, for anyone who wants to have a vial tested independently.

Clear traceability and logistics

The lot number printed on the vial links the product to its documentation. Logistics matter too: fast shipping reduces the time spent out of the cold. Peptinium Labs ships from France within 24 business hours, in plain packaging (see shipping). On receipt, our checklist for receiving an order lets you check the essentials in a few minutes.

Messaging consistent with the framework

A supplier aligned with the RUO framework publishes no dosing, no user testimonials and no promise of effect. The gap between the documentary rigour on display and the sales pitch is often the best indicator.

Reading a certificate of analysis

The certificate of analysis (CoA) is the central document for a research peptide. To read it, look at the following in order:

• identification: product name, lot or task number, analysis date, issuing laboratory;
• HPLC purity: one strongly dominant main peak, a stable baseline, few secondary peaks;
• identity: the mass measured by mass spectrometry must match the theoretical mass of the sequence;
• quantification: the mass actually present in the vial, to be compared with the amount stated on the label.

Each point is explained in HPLC purity ≥ 99%: how to interpret a certificate of analysis. The expected theoretical mass appears on the peptide's data sheet.

A certificate also has its limits. It confirms purity and identity at the time of analysis. It says nothing about stability over time, nor about sterility or endotoxins if those tests are not on it. The appearance of the product does not replace analysis either: most lyophilizates are white, but GHK-Cu is blue, for a chemical reason explained in Why is GHK-Cu blue?. Its close relative, AHK-Cu, shares this colour; their differences are set out in GHK-Cu or AHK-Cu.

Peptinium Labs' Janoshik certificates of analysis are published on our certificates of analysis page. Each one can be verified directly on janoshik.com.

Storage and the cold chain

A research peptide is delivered lyophilized, as a powder. This is no accident: by removing water, lyophilization greatly slows down degradation reactions. The process is explained in Peptide lyophilization explained.

The lyophilizate

The usual reference points in supplier documentation are as follows: −20 °C, in a sealed vial protected from light, for long-term storage; 2 to 8 °C for a shorter period. Room temperature is tolerated during transport, for a few days. Before opening, the vial is allowed to return to room temperature to avoid condensation. The physical chemistry behind these rules is detailed in Stability and the cold chain.

The reconstituted solution

Once in solution, the peptide is exposed again to hydrolysis, oxidation and light. Its stability depends on the molecule, the solvent, the temperature and the number of withdrawals. Two articles review the subject: Lyophilized or reconstituted: storage rules and Reconstituted peptide: how long does it stay stable?.

Three mistakes come up often: shaking the vial vigorously, exposing it to light, and refreezing a solution.

Tracking every vial

Storage that is not recorded is storage that is unknown. Date of receipt, lot number, temperature, date of reconstitution, solvent: this information is enough to link a measurement to a vial. The method is described in Organizing a peptide reagent inventory.

Reconstitution and calculations

Reconstitution means putting the lyophilizate back into solution in a known volume of solvent. The step is simple, but it is where most concentration errors start.

Choosing the solvent

Two solvents come up in laboratory protocols: sterile water and bacteriostatic water, which contains a preservative (0.9% benzyl alcohol). Their composition and limits are described in Bacteriostatic water: composition, role and limits. The choice between the two is discussed in Sterile or bacteriostatic water?.

Calculating concentration

Everything starts from a simple relationship:

Concentration (mg/mL) = peptide mass (mg) ÷ solvent volume (mL)

A 10 mg vial put into solution in 2 mL gives a 5 mg/mL solution. The main source of error is the unit: confusing milligrams and micrograms multiplies or divides a quantity by 1,000. See Converting mg, µg and mL, then the full method in Reconstituting peptides: dilution calculation.

Our reconstitution calculator does these conversions online. From the mass in the vial and the solvent volume, it gives the concentration, then converts a mass into a volume. It is a calculation tool: it recommends no quantity.

Technique and visual inspection

The solvent is added slowly, down the side of the vial, which is then swirled gently, without shaking. See Good reconstitution practice. To measure a small volume accurately, you need to read the graduations correctly: see U-100 syringe: reading the graduations and lab syringe formats. Finally, short-lived foam does not mean the same thing as persistent cloudiness or particles: see Cloudy or foamy solution after reconstitution.

The main peptide families studied

The Peptinium Labs catalog is organized into six families, according to the receptors and models described in the literature. One sentence for each:

• GLP-1 and GIP: analogues of the incretins and amylin, such as RT-3 (R3), a triple agonist of the GLP-1, GIP and glucagon receptors, or cagrilintide; the basics are covered in GLP-1, GIP and glucagon.
• Repair: peptides studied in cell models of migration, extracellular matrix or signalling, such as BPC-157 and TB-500, GHK-Cu, AHK-Cu, KPV, SNAP-8 and the KLOW blend.
• Cognitive: neuropeptides and analogues studied in fundamental neuroscience, including Semax, Selank, DSIP and oxytocin.
• Melanocortin: α-MSH analogues characterized by their affinity for the MC1R to MC4R receptors, such as Melanotan I and II and PT-141.
• Anti-aging: molecules studied in models of cellular metabolism and cellular aging, such as NAD+, glutathione, Epithalon and MOTS-c.
• Growth: GHRH analogues, secretagogues and kisspeptin, studied on the hypothalamic–pituitary axes, such as CJC-1295 and Ipamorelin, Tesamorelin and KissPeptin-10.

All products are listed in the catalog. The results described in the literature concern specific study conditions (cell cultures, experimental models). They do not transfer to any other use.

Key takeaways

• A research peptide is a laboratory reagent, not a medicine. It is not intended for any human or animal use.
• In France, how a product is presented matters as much as its composition: a serious RUO framework rules out any health claim.
• Quality is checked on documents: HPLC purity, mass spectrometry, dated, numbered analysis reports issued by an independent laboratory such as Janoshik.
• The lyophilizate is stored cold and away from light; the reconstituted solution stays stable for a shorter time.
• Reconstitution is first and foremost a calculation: check the units and use the calculator.
• For practical questions (ordering, shipping, documents), see our FAQ.

Research Use Only (RUO). This guide is informative editorial content. It constitutes neither legal advice, nor a recommendation for use in humans or animals, nor a therapeutic claim. Peptinium Labs products are reserved for research professionals, for in vitro research.