Peptide Sciences Shut Down: What Happened, and How to Vet Who You Buy From Next

Short version: Peptide Sciences closed its doors on March 6, 2026. If you were a customer, you have questions — and probably a browser full of tabs from sites that appeared out of nowhere claiming to be them. This page covers what actually happened, why the copycat sites are a problem, and how to size up any research peptide supplier (including us) before you spend a dollar.

One thing up front, so there’s no confusion: Hello Stacks has no affiliation with Peptide Sciences. We are not connected to them, we did not take over their business, and we do not sell their products. We are a separate company that happens to operate in the same corner of the research world. If a website tells you otherwise about anyone, close the tab.

What actually happened

On March 6, 2026, peptidesciences.com stopped selling. The notice posted on their site said the company had voluntarily shut down. That is their statement, and it is the only account that comes straight from the company.

Plenty of blogs have since published theories about why. We are not going to add to the pile — we do not have inside information, and neither do most of the people writing about it. What we can tell you is what disappeared along with the storefront, because that part is measurable:

Hundreds of product pages
A research library of roughly 345 articles
Around 1,000 certificate-of-analysis pages

That last one is the part people underestimate. If you ever bookmarked a COA to check a lot number later, that bookmark is now a dead link. Lesson worth carrying forward: download the COA for every lot you buy, from anyone, and keep your own copy. A certificate that lives only on someone else’s server is a certificate you can lose overnight.

Careful: a lot of sites are using their name right now

Since the shutdown, several storefronts have popped up trading on the Peptide Sciences name — some of them borrowing the branding almost pixel-for-pixel.

You do not have to take our word that this is a problem. On April 15, 2026, Peptide Sciences updated its own notice to state that any site, platform, or individual claiming affiliation with them, presenting themselves as continuing their business, or claiming to sell their products is unauthorized and has no connection to the company.

So the rule is simple: if a site leans on the Peptide Sciences name to sell you something, that is a red flag, not a credential. A real supplier stands on its own name and its own paperwork.

How to vet a research peptide supplier (the useful part)

Here is the honest framing: we sell peptides, so of course we would like you to buy from us. That is exactly why this section is written as criteria instead of a ranking. Use it on us. Use it on everyone. If a vendor can’t clear these bars, it doesn’t matter how good the website looks.

1. Ask for the COA — and check that it matches your vial

A Certificate of Analysis is the lab report for a specific batch. The single most common trick in this space is a vendor showing you a COA rather than your COA.

A COA worth trusting shows:

A lot / batch number that matches the number printed on the vial you received
HPLC purity — an actual percentage, not a marketing adjective
Mass spectrometry (MS) confirming the compound is what the label says it is. Purity tells you how clean it is; MS tells you what it is. You want both.
The name of the lab that ran it, and the date it was run
Quantity / fill where applicable

Missing lot number? Undated? No lab named? Purity described as “high” instead of a number? Those are all the same answer: move on.

2. Know what the purity numbers actually mean

HPLC purity	How the field generally reads it
Below 95%	Below the common baseline — ask questions before anything else
96–98%	The usual working standard for research material
99%+	Considered excellent

And a nuance nobody advertises: purity is not the whole story. A vial can be 99% pure and still be the wrong compound, or under-filled, or degraded from a warm week in transit. Purity + identity (MS) + correct fill + sane handling is the actual bar.

3. Third-party testing beats “we test in-house”

In-house testing is not worthless, but it is a company grading its own homework. An independent lab has no reason to flatter the result. Ask who runs the testing, and whether the report you’re shown came from them.

4. Check whether the COAs are even reachable

Try it before you order. Can you find the COA for a specific product without emailing anyone? Can you match it to a lot? If certificates are “available on request,” you are being asked to trust first and verify later — which is backwards.

5. Look at how they handle shipping, storage, and the boring stuff

How is material shipped, and does the vendor say anything about temperature at all?
Are storage and reconstitution instructions provided, or are you expected to already know?
Is there a real, findable way to reach a human — and does anyone answer?
Is the pricing transparent, or does the total mutate at checkout?

6. Watch how they talk about their products

This one is a genuine tell. Research-grade material is sold for laboratory research use only. A vendor that starts promising outcomes, dosing you like a clinic, or guaranteeing results has told you something important about how carefully they run the rest of their operation.

The 60-second checklist

Copy this. Run it on any vendor, us included.

☐ COA available before I buy, not on request
☐ COA lot number matches the vial I actually receive
☐ HPLC purity shown as a real number
☐ Mass spec identity confirmation included
☐ Independent lab named on the report
☐ Test date present and recent
☐ Storage + reconstitution guidance provided
☐ A human answers when I ask a question
☐ Clear pricing and shipping, no checkout surprises
☐ Research-use framing — no promises, no guarantees
☐ Not leaning on somebody else’s brand name to sell me something

Where Hello Stacks fits

We are not going to publish a ranking of our own competitors and pretend it’s neutral. Instead, here is how we answer the checklist above — verify it yourself rather than taking our word for it:

Every lot gets a Certificate of Analysis, and it’s tied to the lot number on the vial.
Independent third-party lab testing, with the reports published rather than held back for people who ask nicely.
The actual numbers are on the page — HPLC purity and identity confirmation, not adjectives.
US-based operation with real support you can reach.
Research Use Only, stated plainly everywhere — no outcome promises, because that isn’t what this material is for.

If any of that ever fails to check out, we would genuinely rather hear about it than not. Tell us.

Browse the catalog and check the COAs yourself →

Frequently asked

Did Peptide Sciences really shut down?

Yes. The site stopped selling on March 6, 2026, and the company’s own notice described it as a voluntary shutdown.

Is Peptide Sciences coming back?

We have no idea, and anyone telling you they do know is guessing. Their notice did not announce a return.

Are the sites using the Peptide Sciences name legitimate?

Peptide Sciences publicly stated in April 2026 that any site claiming affiliation with them, presenting itself as continuing their business, or claiming to sell their products is unauthorized and unconnected to the company. Treat those sites accordingly.

Is Hello Stacks affiliated with Peptide Sciences?

No. No affiliation, no connection, no relationship of any kind. We did not acquire them, we did not take over their business, and we do not sell their products. We are an independent company. We’d rather say that plainly than let anyone assume otherwise.

What should I look for in a different supplier?

Start with the checklist above. The short version: a per-lot COA you can see before you buy, HPLC purity as a real number, mass-spec identity confirmation, an independent lab named on the report, and a company that talks about research instead of promising you results.

My old Peptide Sciences COA links are dead. Can I still get them?

Almost certainly not — those pages went down with the site. It’s a good argument for saving a copy of the COA for every lot you buy going forward, from any supplier.

Research Use Only. All products are supplied strictly for laboratory research. Nothing on this page is medical advice, and nothing here should be read as a claim about outcomes.

Peptide Sciences is a trademark of its respective owner. It is referenced here only to describe publicly reported events. Hello Stacks is not affiliated with, endorsed by, or connected to Peptide Sciences in any way.