Research centre
Practical reference for handling lyophilized peptides in the laboratory: reconstitution, storage, solubility and a compound index with molecular weights and CAS numbers. Written for research use, not for any clinical purpose.
What research peptides are
Peptides are short chains of amino acids joined by peptide bonds, generally fewer than fifty residues. Synthetic research peptides are produced by solid-phase peptide synthesis, purified by reverse-phase HPLC and supplied as a lyophilized (freeze-dried) powder, usually as an acetate or trifluoroacetate salt. In this form they are stable for extended periods when kept cold and dry.
Everything in our catalogue is supplied for in-vitro laboratory research. The compound summaries on product pages describe the receptor or pathway each peptide is studied against in the published literature; they are not claims about effects in any organism.
Reconstitution
Lyophilized peptide is dissolved in a sterile diluent to produce a solution of known concentration. Bacteriostatic water (0.9% benzyl alcohol) is the usual choice for multi-draw vials because the preservative limits microbial growth; sterile water or a buffer may suit single-use preparations or assays sensitive to benzyl alcohol.
- Allow the vial to reach room temperature before opening to avoid condensation on the cold powder.
- Swab the stopper. Draw the planned volume of diluent and introduce it slowly down the inside wall of the vial rather than onto the cake.
- Let the cake dissolve. Gentle swirling is fine; do not shake, as foaming can denature some sequences.
- Record the resulting concentration on the vial. Use the calculator to work it out.
Storage and handling
Unopened lyophilized vials: −20 °C, desiccated and protected from light. Brief excursions to room temperature, such as during shipping, are generally tolerated for most sequences. Reconstituted solutions: 2–8 °C, protected from light, and used within the period appropriate to your protocol; freeze aliquots at −20 °C or below if longer storage is needed, and avoid repeated freeze-thaw cycles. Peptides containing cysteine, methionine or tryptophan are more oxidation-prone and benefit from minimal headspace and prompt use.
Solubility
Most peptides in the catalogue dissolve readily in water at the concentrations typically used. Highly hydrophobic sequences may need a small volume of a co-solvent (for example, dilute acetic acid for basic peptides, dilute ammonium bicarbonate for acidic peptides, or a few percent DMSO) before dilution with water. GHK-Cu dissolves to a characteristic blue solution. If a solution is cloudy, the peptide has not fully dissolved; sonication for a few seconds usually resolves it.
Reading a certificate of analysis
A COA lists the lot, the analytical method and the measured purity (usually HPLC area-percent at 214 or 220 nm), and an MS result confirming molecular weight. Purity is a measure of the proportion of the peptide peak relative to other UV-absorbing species; net peptide content, where reported, accounts for water and counter-ion and is typically lower. See the COA page to look up a lot.
Compound index
| Compound | Category | MW | CAS |
|---|---|---|---|
| Retatrutide | Metabolic research | 4731.3 g/mol | 2381089-83-2 |
| Tirzepatide | Metabolic research | 4813.5 g/mol | 2023788-19-2 |
| Semaglutide | Metabolic research | 4113.6 g/mol | 910463-68-2 |
| Cagrilintide | Metabolic research | 4409.0 g/mol | 1415456-99-3 |
| AOD-9604 | Metabolic research | 1815.1 g/mol | 221231-10-3 |
| 5-Amino-1MQ | Metabolic research | 173.2 g/mol (cation) | 42464-96-0 |
| BPC-157 | Tissue & recovery research | 1419.5 g/mol | 137525-51-0 |
| TB-500 | Tissue & recovery research | 4963.4 g/mol | 77591-33-4 |
| TB-500 + BPC-157 Blend | Blends | 4963.4 / 1419.5 g/mol | 77591-33-4 / 137525-51-0 |
| KPV | Tissue & recovery research | 342.4 g/mol | 67727-97-3 |
| Thymosin Alpha-1 | Tissue & recovery research | 3108.3 g/mol | 62304-98-7 |
| CJC-1295 (No DAC) | Growth hormone axis | 3367.9 g/mol | 863288-34-0 |
| Ipamorelin | Growth hormone axis | 711.9 g/mol | 170851-70-4 |
| CJC-1295 (No DAC) + Ipamorelin Blend | Blends | 3367.9 / 711.9 g/mol | 863288-34-0 / 170851-70-4 |
| Tesamorelin | Growth hormone axis | 5135.9 g/mol | 218949-48-5 |
| Sermorelin | Growth hormone axis | 3357.9 g/mol | 86168-78-7 |
| Semax | Neuro & cognition | 813.9 g/mol | 80714-61-0 |
| Selank | Neuro & cognition | 751.9 g/mol | 129954-34-3 |
| Selank + Semax Blend | Blends | 751.9 / 813.9 g/mol | 129954-34-3 / 80714-61-0 |
| DSIP | Neuro & cognition | 848.8 g/mol | 62568-57-4 |
| PT-141 (Bremelanotide) | Neuro & cognition | 1025.2 g/mol | 189691-06-3 |
| Melanotan II | Skin & cosmetic research | 1024.2 g/mol | 121062-08-6 |
| Oxytocin | Neuro & cognition | 1007.2 g/mol | 50-56-6 |
| Pinealon | Neuro & cognition | 303.3 g/mol | n/a (Glu-Asp-Arg) |
| GHK-Cu | Skin & cosmetic research | 403.9 g/mol (Cu complex) | 89030-95-5 |
| SNAP-8 | Skin & cosmetic research | 1075.2 g/mol | 868844-74-0 |
| GLOW Blend | Blends | Mixed (GHK-Cu 50 mg / BPC-157 10 mg / TB-500 10 mg) | Mixed |
| KLOW Blend | Blends | Mixed (GHK-Cu 50 mg / BPC-157 10 mg / TB-500 10 mg / KPV 10 mg) | Mixed |
| MOTS-c | Mitochondrial & longevity | 2174.6 g/mol | 1627580-64-6 |
| NAD+ | Mitochondrial & longevity | 663.4 g/mol | 53-84-9 |
| SS-31 (Elamipretide) | Mitochondrial & longevity | 639.8 g/mol | 736992-21-5 |
| Epitalon | Mitochondrial & longevity | 390.3 g/mol | 307297-39-8 |
| Thymalin | Mitochondrial & longevity | Polypeptide fraction | n/a |
| Kisspeptin-10 | Neuro & cognition | 1302.4 g/mol | 374675-21-5 |
Reference values from the literature for the base compound. Confirm against the batch COA.