Research peptides are short chains of amino acids, made synthetically and supplied for laboratory and in vitro work. This guide covers the basics every lab needs before a vial is opened: what "research use only" means, how quality is verified, and how peptides are stored and reconstituted. Each section links to a full guide.
What research peptides are
A peptide is a molecule built from amino acids joined by peptide bonds - typically anywhere from two to about fifty residues. Many occur naturally as signalling molecules, fragments of larger proteins, or hormones. Research peptides are synthetic versions or analogs of these sequences, produced so that their behaviour can be studied in cell models, tissue preparations and preclinical research.
Most are supplied lyophilized - freeze-dried into a powder or "cake" at the bottom of a sealed vial. Lyophilization removes water, which is what makes a peptide stable enough to ship and store. Before use in the lab it is dissolved again in a suitable diluent, a step called reconstitution.
What "research use only" means
"Research use only" (RUO) is a supply designation. It means the material is provided for laboratory research and development - not manufactured, tested or approved for administration to people or animals. RUO peptides are not drugs, dietary supplements, cosmetics or medical devices, and they have not been evaluated by the U.S. Food and Drug Administration.
The label is a statement about intended use, so it applies to everything around the product, too: a supplier that pairs an RUO label with human-use claims is contradicting its own label. At Moleano, every product page, guide and order carries the same research-only terms.
How quality is verified
Two measurements answer the two questions that matter:
- Purity - HPLC. High-performance liquid chromatography separates the sample into its components. The share of the signal that belongs to the main peak is the purity figure, such as 99%.
- Identity - mass spectrometry. MS measures molecular weight. A measured mass that matches the expected mass of the sequence is strong evidence the vial holds the labelled peptide.
A sample can look pure by HPLC and still be the wrong molecule, which is why both are needed. Moleano publishes third-party HPLC and mass-spectrometry reports by lot number. Read more in How peptide purity is tested.
Storage basics
- Lyophilized, long term: frozen at -20 °C (or -80 °C for sensitive sequences), sealed, dry and dark.
- Lyophilized, short term: a refrigerator at 2-8 °C is adequate for vials used within weeks.
- Reconstituted: refrigerated at 2-8 °C for short-term use, or split into aliquots and frozen for longer; labelled with the date, never left at room temperature.
- Let a cold vial reach room temperature before opening it, so moisture does not condense inside.
Full detail: How to store peptides.
Reconstitution basics
Reconstitution means adding a measured volume of diluent - usually bacteriostatic water - to the lyophilized peptide. The diluent is run slowly down the inside wall of the vial, and the vial is swirled, not shaken, until the solution is clear. The volume added sets the concentration; it does not change how much peptide is in the vial.
Concentration (mg/mL) = peptide in the vial (mg) / diluent added (mL). The reconstitution calculator does the arithmetic, and the step-by-step guide covers technique. For choosing a diluent, see bacteriostatic vs sterile water.
Guides by research area
Compound guides summarise what the published literature does - and does not - show, with sources. The first is BPC-157 vs TB-500, comparing two of the most-studied peptides in tissue-repair research. More guides are added over time.
All research guides
- How to Reconstitute PeptidesStep-by-step lab method for reconstituting lyophilized peptides: what you need, adding the diluent safely, and working out the concentration.
- Reconstitution CalculatorFree peptide reconstitution calculator: enter the vial amount and diluent volume to get mg/mL, mcg/mL and the volume that holds a target amount.
- How to Store PeptidesHow to store research peptides: freezer and fridge temperatures for lyophilized powder, keeping out moisture and light, and storing solutions.
- Bacteriostatic vs Sterile WaterBacteriostatic vs sterile water as a peptide diluent: the 0.9% benzyl alcohol difference, multi-use vs single-use, and when to use each.
- Peptide Purity TestingHow peptide purity and identity are tested: what an HPLC purity figure means, what mass spectrometry can and cannot show, and what a report should show.
- BPC-157 vs TB-500BPC-157 vs TB-500 compared for researchers: where each peptide comes from, the research areas each is studied in, and how strong the evidence is.
Frequently asked questions
What is a research peptide?
A short chain of amino acids made synthetically and sold for laboratory and in vitro research. Research peptides are not approved drugs or supplements and are not for human or veterinary use.
What does "research use only" mean?
It means the material is supplied for laboratory research and development. It is not manufactured, tested or approved for administration to people or animals.
How is a research peptide checked?
HPLC (high-performance liquid chromatography) estimates chromatographic purity. Mass spectrometry checks consistency with the expected molecular mass; additional analysis may be needed to distinguish sequences or isomers.
Research use only. All products sold by Moleano Peptides are intended solely for laboratory research. They are not for human or veterinary use and are not drugs, supplements or medical devices. This guide is educational and is not medical advice.