Peptide Sciences Alternative: Switching Research Peptide Suppliers in the USA

If you previously sourced research compounds from Peptide Sciences, you are probably now looking for a new supplier. This page sets out what is publicly known about the closure, what to check before you move your orders anywhere else, and how ExoLabz answers each of those checks for laboratories in the United States. Every product we sell is supplied strictly for in-vitro laboratory research use only.

What happened to Peptide Sciences

According to a notice on its website, peptidesciences.com, “Peptide Sciences has decided to voluntarily shut down operations and discontinue the sale of its research products.” When we checked the site on 30 September 2026, the notice was still in place and the store was no longer selling.

The notice does not give a reason for the decision, a closing date or guidance on earlier orders, and we are not going to guess at any of those. If you have an open question about a past order, the notice itself is the only first-hand source we are aware of.

The same notice also warns that any website, platform or individual claiming to be affiliated with Peptide Sciences without authorization is not genuine. That is worth taking seriously. When a well-known name leaves a market, look-alike domains and “official successor” claims tend to follow. ExoLabz is an independent supplier with no connection to Peptide Sciences, and we make no claim otherwise.

What to check before switching suppliers

Changing suppliers mid-project is a risk to your data. A different synthesis route, a different purification standard or a different counter-ion can all show up as noise between experiments. The points below are the ones that decide whether a new source is actually comparable to the one you had.

1. Identity confirmed by mass spectrometry

Purity and identity are different questions. An HPLC trace tells you how much of the sample is one main component; it does not tell you that component is the sequence on the label. Identity is normally confirmed by mass spectrometry (MS or LC-MS), which should show an observed mass matching the calculated molecular weight. Ask whether identity testing is done and whether the result is shown.

2. The HPLC chromatogram itself, and the wavelength

A purity percentage on its own is a claim; the chromatogram is the evidence. A useful report shows the trace, the integrated peaks and the detection wavelength. Peptide purity is usually read around 214–220 nm, where the peptide bond absorbs. A figure measured at a different wavelength can look better than the sample really is, because some impurities barely absorb there.

3. Third-party versus in-house testing

In-house QC has its place, but an independent laboratory has no stake in the result. Check that the report names the testing lab, carries a sample or report ID and gives a test date, so you can tell what was tested and when.

4. Net peptide content

Lyophilized peptide powder is not 100% peptide. It also holds counter-ions (often acetate or trifluoroacetate) and residual water. HPLC purity describes the peptide fraction only; net peptide content describes how much of the weighed powder is peptide at all. If your work depends on exact concentrations, ask whether net content has been measured or whether you should plan to determine it yourself.

5. Lot traceability

A certificate only helps if you can link it to the vial on your bench. Look for a clear way to match a vial to its test report, whether that is a lot number, a batch code or another physical marker, and keep that record with your lab notes.

6. Domestic US shipping

Where an order ships from affects transit time, customs exposure and how long the material sits in uncontrolled conditions. A supplier that ships from inside the United States avoids international customs holds entirely. Also check the dispatch window and whether every order comes with tracking.

7. Payment and support

Can you reach a person when a parcel stalls or a question comes up about a certificate? Is the checkout process clear, and does the supplier state its terms plainly, including that products are for research use only? A supplier that is vague about its own terms is unlikely to be precise about anything else.

8. Price per milligram, not price per vial

Vial sizes differ between suppliers, so headline prices are hard to compare. Divide the price by the milligram content to get a true cost per mg, then factor in shipping and any quantity discount for the quantities your experiments actually need.

Vendor-evaluation checklist

Use this table to compare any supplier you are considering, including us.

How ExoLabz handles each point

ExoLabz supplies research peptides to laboratories across the United States from our US research peptide range. Here is how we measure up against the checklist, stated plainly.

• Testing: our peptides go through third-party HPLC and purity testing, carried out by independent laboratories rather than in-house.
• Published certificates: certificates of analysis are published for some products, not every product or batch. The full collection we have published is on our COAs page. If you need documentation for a specific product that is not shown there, ask us before you order.
• Traceability: vials are matched to their certificates by cap and crimp color, so you can tie the vial on your bench to the report it belongs to.
• US shipping: orders ship from inside the United States with tracked delivery, and are dispatched within one business day. There is no international customs step.
• Shipping cost: shipping is free on orders over $200.
• Pricing: quantity pricing is applied in the cart, so the per-mg cost falls as your order grows. You can compare sizes and costs on our research peptide price list, and larger programs can use our bulk peptide ordering page.
• Terms and support: everything we sell is for laboratory research use only, and our FAQ covers ordering, shipping and documentation questions.

We would rather you run the checklist than take our word for it. For a longer walk-through of the same process, see choosing a research peptide supplier in the USA.

A practical plan for switching

1. List the compounds and quantities your current projects need, and note the vial sizes you were using.
2. For each compound, compare cost per mg across suppliers rather than cost per vial.
3. Check what testing evidence is available for that specific compound before ordering: chromatogram, wavelength, testing lab and identity data.
4. Start with a small order and run your own verification against earlier material before you commit a full study to a new source.
5. Record the certificate and vial marking for every lot you receive, so any variation between lots can be traced later.

Frequently asked questions

Has Peptide Sciences shut down?

According to a notice on peptidesciences.com, the company “has decided to voluntarily shut down operations and discontinue the sale of its research products.” The notice was live when we checked on 30 September 2026. It does not state a reason or a date.

Is ExoLabz connected to Peptide Sciences?

No. ExoLabz is an independent supplier. We have no affiliation with Peptide Sciences and do not present ourselves as a successor to it. The Peptide Sciences notice itself warns against anyone claiming unauthorized affiliation.

Does every ExoLabz product have a published COA?

No. Certificates are published for some products, and the full published collection is on our COAs page. All testing is carried out by third-party labs, and vials are matched to their certificates by cap and crimp color.

How fast do US orders ship?

Orders ship from within the United States and are dispatched within one business day, with tracking on every parcel. Shipping is free on orders over $200.

Can I use ExoLabz peptides outside the lab?

No. All ExoLabz products are sold strictly for in-vitro laboratory research use only. They are not for human or animal use of any kind, and we do not provide guidance on any use outside a research setting.

All ExoLabz products are intended for laboratory research use only. Not for human or veterinary use.