Last checked: October 29, 2026.
The 30-second answer
There's no official Peptide Sciences replacement. It closed on March 6, 2026 and hasn't relaunched. A good alternative is any vendor that passes five checks you can run yourself. Look for a lot-specific COA, mass-spec identity, no human-use marketing, a real business and normal payment.
A label is a promise, not proof
In 2024, researchers bought semaglutide from online sellers. Three vials arrived labeled 99% pure. They measured 7.7% to 14.37%. [1]
That's the problem a Peptide Sciences alternative has to solve. You need a vendor that proves what's in each vial, not one that just says so.
In this article you'll learn:
- Five deal-breaker checks that rule out most bad vendors in minutes
- Eight scored checks that separate adequate vendors from strong ones
- How to switch vendors mid-project without wrecking your data
We don't publish a ranked list of named vendors. Lots change, labs change and vendors close. Criteria last.
Current status of the original company: Is Peptide Sciences shut down? Dated status and timeline
Who replaced Peptide Sciences?
Nobody, and that's the wrong question. Sites claiming to be the relaunched brand appeared within weeks of the March 6 closure.
One, peptidesciencesinc.com, was registered on April 17, 2026. It's unaffiliated with the original company and is now on registrar clientHold (a freeze placed by the domain registrar).
No vendor inherited Peptide Sciences' lots, testing records or lab relationships. Its old COAs tell you nothing about anyone else's vials.
So ask a narrower question: does this vendor prove what's in each vial? Everything below answers that from documents you can check yourself.
What are the five deal-breaker checks?
Fail one, and the vendor is out, whatever the price.
| # | Check | Pass | Fail |
|---|---|---|---|
| 1 | Lot-specific COA, public before you buy | COA on the product page; lot number matches the vial; test date and lab shown | "COA on request"; one COA reused across lots; no lot number |
| 2 | Identity by mass spectrometry | Observed mass reported against the expected mass for the sequence | HPLC purity only, no identity data |
| 3 | No human-use marketing | Research-only framing on the site, in emails and on social | Dosing charts, injection guides, "results" testimonials, body photos |
| 4 | A verifiable business | Named legal entity, address, working support, domain history that fits | Anonymous 2026 domain claiming to be a closed brand |
| 5 | Normal payment | Card payment with standard dispute rights | Crypto-only, gift cards, "friends and family" transfers, surprise "customs fees" |
Checks 1 and 2: the paperwork
A COA (certificate of analysis) is a lab report card for one batch, or "lot." A lot-specific COA works like a best-by date stamped on one carton. It tells you about that carton, not the brand.
In the 2024 Pécs/UC San Diego test buys, all three vials that arrived carried 99% claims. None came close. Two of the three carried "research use only" labels. [1]
Purity and identity are different questions. HPLC is a race where each molecule crosses the finish line at its own time. It reports what share of the signal sits in the main peak. Mass spectrometry is a scale that weighs the molecule. It confirms the molecule matches the sequence on the label.
USP and MHRA scientists list mass spectrometry, NMR and amino acid analysis among the identity tests for synthetic peptides. They're separate from purity tests. [4]
Did you know? Two custom peptides reported at 98.44% and 98.34% HPLC purity turned out to be 20% and 43% undeclared mannitol, a sugar alcohol. HPLC didn't flag it. NMR did. [3]
Deep dive: HPLC vs. mass spectrometry for peptides
Check 3: the marketing
FDA judges a product by its "intended use." Under 21 CFR 201.128, intent can show up in "labeling claims, advertising matter, or oral or written statements." A "research use only" sticker doesn't cancel a dosing chart. [8]
FDA sent five warning letters to online peptide vendors in August 2026. Their labels said "for research, laboratory, and analytical use." FDA pointed to their websites instead: dosing information, injection instructions, dose calculators and bacteriostatic water offered for injection prep. [7]
A vendor in FDA's sights can vanish mid-project. Peptide Sciences customers already know what that costs.
Check 4: the business
Run a whois lookup (a public record of who registered a domain, and when). A domain registered after March 6, 2026 that claims Peptide Sciences' history is a copycat. Then look for a legal entity name, a street address and policy pages that match the product labels.
Check 5: the payment
The same research group placed six test orders in 2024. Only three arrived. Scammers asked for an extra $650 to $1,200 to "clear customs." [2]
In the group's vendor survey, 66% of sellers offered cryptocurrency payment. [1] Card payments keep your chargeback rights. That matters when a vendor goes dark, as Peptide Sciences did.
What this means for you: Five quick checks remove most bad options before you spend a cent. If a vendor fails one, the price doesn't matter.
What separates a good vendor from a great one?
Once a vendor clears the five checks, these eight rank it. Our companion rubric turns them into a 100-point score: Best peptide vendors 2026: the scoring rubric
| Check | What to ask for | Why it matters |
|---|---|---|
| 1. Named independent lab | Lab name on the COA; ISO/IEC 17025 accreditation and scope | The standard lets labs "demonstrate that they operate competently and generate valid results" [9] |
| 2. Endotoxin result | Bacterial endotoxins test (LAL, USP <85>) with a number in EU/mg | One 2024 test-buy vial measured 8.9511 EU/mg [1] |
| 3. Net peptide content | Peptide content plus water (Karl Fischer) and counterion (TFA or acetate) data | Freeze-dried powder isn't 100% peptide. HPLC purity doesn't measure the rest [4] |
| 4. Elemental impurities | Heavy-metal screen (arsenic, lead, cadmium, mercury) | Falsified peptides in Belgium carried arsenic and lead, some up to 10× the ICH limit for injectables [5] |
| 5. Cold chain | Insulated packaging, cold packs, stated transit time, storage temps on the label | Freeze-dried secretin lost 20–27% of its HPLC concentration by week 8 in stability testing [6] |
| 6. Written refund or reship policy | Terms for damaged, warm-arrival or failed-retest vials | Puts the vendor's money behind its COA |
| 7. Lot history | More than one lot per compound; past COAs kept online | One good COA is a snapshot. Five is a track record |
| 8. Per-component blend data | Separate purity and mass for every compound in a blend | One combined number hides which part is short |
A few of these need a plain-English note:
- Endotoxin is the "smoke" left behind by dead bacteria. Sterile filters can't catch it, so it has to be tested. EU/mg means endotoxin units per milligram. Endotoxin testing explained
- ISO/IEC 17025 is the international standard for testing labs. Accreditation covers a set "scope" of methods, so check that the scope includes HPLC or LC-MS.
- Net peptide content is how much of the powder is actually peptide. A 99% purity figure says the peptide is clean relative to other peptide-like material. It doesn't say how many milligrams of peptide sit in the vial.
Verify the lab, not just the logo
Email the lab named on the COA. Ask it to confirm the report number and lot. A COA from an unnamed "in-house lab" is the vendor grading its own homework.
Lab landscape: Peptide testing labs explained
The shipping box is part of the product
Heat and humidity change freeze-dried peptides. In the 2015 secretin study, samples were kept at 25°C and 60% relative humidity. Particle size grew from about 390 nm to over 2 µm within one week. [6]
Ask how the vendor ships in summer. A plain padded envelope is an answer.
Handling guide: Peptide storage and handling
What this means for you: The five checks keep you safe from the worst vendors. The eight checks tell you which survivor deserves your project.
Myth vs. fact
| Myth | Fact |
|---|---|
| "99% on the label means 99% in the vial." | Three test-buy vials labeled 99% measured 7.7% to 14.37%. |
| "High HPLC purity proves it's the right peptide." | HPLC measures cleanliness, not identity. Mass spectrometry confirms identity. |
| "A 'research use only' label keeps a vendor out of trouble." | FDA's August 2026 letters went to vendors with research labels, based on their websites. |
| "Some new site is the official Peptide Sciences relaunch." | There's no relaunch. peptidesciencesinc.com is unaffiliated and on registrar hold. |
How do you run the checklist in 15 minutes?
- Whois the domain. Note the registration date and registrar status.
- Open a product page. Find the COA without logging in or emailing.
- Match the lot. COA lot number, product name and quantity should match the vial label photo.
- Read the COA. Lab name, test date, HPLC purity, observed vs. expected mass, endotoxin result. How to read a certificate of analysis
- Check the lab. Confirm it exists, is independent and holds relevant accreditation.
- Read the policies. Refund, shipping, terms. Look for a legal entity name.
- Scan for human-use content. Blog posts, FAQs, social accounts, email flows.
- Start small. Place one small order, log every lot number, and consider an independent retest before scaling up.
Your next step: score the vendors that pass with our rubric: Best peptide vendors 2026: the criteria that matter. Then check ours: See the ProGrade COA library.
How do you switch vendors mid-project?
Handle a vendor change as an experimental variable. Your earlier data came from different lots, made and tested by different people.
- Record vendor, lot number, COA purity, observed mass and storage conditions for every vial.
- If you kept material from the old supplier, run a side-by-side identity and purity check before you rely on the new lots.
- Don't mix lots from two vendors in one experimental arm.
What red flags rule a vendor out?
- Claims to be "the new Peptide Sciences" or "Peptide Sciences Inc"
- COAs with no lab name, no lot number, or the same test date on every product
- Purity shown with no chromatogram or mass data
- Human dosing tables, injection walkthroughs, or "before and after" posts
- Prices far below every other vendor for the same compound and quantity
- Crypto-only checkout, or payment requests outside the website
How does ProGrade score on its own checklist?
We wrote this checklist, so hold us to it.
- Lot-specific COA published before you buy: yes, every lot. ProGrade COA library
- HPLC purity and MS identity: every lot third-party tested to ≥99% by HPLC/MS.
- Human-use marketing: none. Every product is sold for laboratory research use only.
- Lab name, accreditation, endotoxin, heavy metals, cold chain and refund terms: we'll add these lines when the evidence is live on our site.
If any line doesn't match what you see on our site, tell us. We'll correct the page or the process.
Did the 2026 FDA and HHS moves change any of this?
No. Here's why. (Last checked October 29, 2026.)
On July 23–24, 2026, FDA's Pharmacy Compounding Advisory Committee voted to recommend BPC-157, KPV and TB-500 (8–6) and MOTS-c (7–5) for the 503A bulks list. That's FDA's list of raw ingredients pharmacies can use to mix a drug for one patient. Epitalon and semax were also recommended. [11]
On October 28, 2026, HHS issued an interim enforcement-discretion policy for 503A compounding of BPC-157, TB-500, KPV, MOTS-c, epitalon and semax. In plain English, HHS won't act against licensed pharmacies that compound those six in named forms and routes, on a prescription. It excludes 503B outsourcing facilities (larger, FDA-registered compounders). [12]
| What changed | What didn't |
|---|---|
| A narrow, conditional pharmacy pathway for six peptides | None of them is FDA-approved |
| HHS ended Category 2 status (FDA's red-flag list) as of Apr 22, 2026 | None is on the bulks list. Rulemaking continues |
| HHS published a detailed COA standard for compounding | Research-use-only products aren't covered |
Full explainer: The FDA's July 2026 peptide vote, explained
The evidence in detail
| Study | What it tested | Key findings |
|---|---|---|
| Ashraf et al., 2024, JMIR | Online semaglutide sellers; test buys | Vials labeled 99% measured 7.7%–14.37% purity; 28.56%–38.69% more peptide than labeled; one vial at 8.9511 EU/mg endotoxin; 66% of sellers offered crypto |
| Ashraf et al., 2024, JAMA Netw Open | Six no-prescription test orders | Three arrived; non-delivery scammers asked $650–$1,200 in "customs" fees |
| Choules et al., 2019/2020, J Pharm Biomed Anal | Two commercial custom peptides | 98.44% and 98.34% HPLC purity; NMR found 20% and 43% w/w undeclared mannitol that HPLC-UV missed |
| McCarthy et al., 2023, Pharm Res (USP/MHRA authors) | Reference standards for synthetic peptides | MS, NMR and amino acid analysis listed as identity tests; Karl Fischer for water |
| Janvier et al., 2018, Talanta | Falsified peptide drugs, Belgian market | Arsenic and lead found, some up to 10× the ICH parenteral limit |
| Srinivasan et al., 2015, Int J Pharm | Freeze-dried secretin stability | 20–27% HPLC concentration loss by week 8; particles ~390 nm → >2 µm in 1 week at 25°C/60% RH |
Funding and conflict notes: The 2024 test buys were run by university researchers (Pécs and UC San Diego). The cited studies name specific sellers; this article doesn't. ProGrade is a vendor and wrote this checklist, which is why our own answers are published above.
For research use only. Not for human consumption. These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.
References
- Ashraf AR, Mackey TK, Vida RG, et al. Multifactor quality and safety analysis of semaglutide products sold by online sellers without a prescription. J Med Internet Res. 2024;26:e65440. pmc.ncbi.nlm.nih.gov/articles/PMC11582493/ (doi:10.2196/65440)
- Ashraf AR, Mackey TK, Schmidt J, et al. Safety and risk assessment of no-prescription online semaglutide purchases. JAMA Netw Open. 2024;7(8):e2428280. pmc.ncbi.nlm.nih.gov/articles/PMC11297364/
- Choules MP, Bisson J, Simmler C, et al. NMR reveals an undeclared constituent in custom synthetic peptides. J Pharm Biomed Anal. 2020;178:112915. pmc.ncbi.nlm.nih.gov/articles/PMC6913887/
- McCarthy D, Han Y, Carrick K, et al. Reference standards to support quality of synthetic peptide therapeutics. Pharm Res. 2023;40(6):1317+. pmc.ncbi.nlm.nih.gov/articles/PMC10338602/
- Janvier S, Cheyns K, Canfyn M, et al. Impurity profiling of the most frequently encountered falsified polypeptide drugs on the Belgian market. Talanta. 2018;188:795–807. europepmc.org/article/MED/30029448
- Srinivasan C, Siddiqui A, Korang-Yeboah M, Khan MA. Stability characterization and appearance of particulates in a lyophilized formulation of a model peptide hormone, human secretin. Int J Pharm. 2015;481(1–2). pubmed.ncbi.nlm.nih.gov/25636302/ (abstract re-checked 2026-10-29: "decrease in secretin concentration by 8 week (20-27% fold decrease)"; the abstract doesn't name the storage condition for that figure)
- McDermott Will & Schulte. Federal regulators and state boards crack down on RUO peptides. Sept 24, 2026. www.mcdermottlaw.com/insights/federal-regulators-and-state-boards-crac…
- 21 CFR 201.128, Meaning of "intended uses." eCFR. www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-201/subpart-…
- ISO. ISO/IEC 17025: Testing and calibration laboratories. www.iso.org/ISO-IEC-17025-testing-and-calibration-laboratories.html
- FDA. Pyrogen and Endotoxins Testing: Questions and Answers (guidance; concerns USP <85> Bacterial Endotoxins Test). www.fda.gov/regulatory-information/search-fda-guidance-documents/pyrog…
- FDA. July 23–24, 2026: Meeting of the Pharmacy Compounding Advisory Committee. www.fda.gov/advisory-committees/advisory-committee-calendar/july-23-24… (opened 2026-10-29 in the reader-first pass; tallies per the batch-2 brief's verified list)
- HHS. Enforcement Discretion Policy Regarding 503A Compounding Using Certain Peptide Bulk Drug Substances, with Appendices A and B. www.hhs.gov/sites/default/files/hhs-503a-peptide-enforcement-discretio… ; Federal Register doc. 2026-22192 (public inspection Oct 28, 2026; publication Oct 30, 2026): www.federalregister.gov/d/2026-22192 (both opened 2026-10-29)
Research use only
This article is provided for educational and informational purposes and summarizes published laboratory and preclinical research. All ProGrade Peptides products are sold strictly for in-vitro laboratory and research use only (RUO). Nothing here is medical advice, a therapeutic claim, or a protocol for human or animal use. These compounds are not intended to diagnose, treat, cure, or prevent any disease.
Frequently asked questions
Any vendor that passes all five deal-breaker checks: a lot-specific COA before purchase, mass-spectrometry identity, no human-use marketing, a verifiable business and normal payment. Then compare survivors on lab independence, endotoxin data, net peptide content, cold chain and refund terms.
No. As of October 29, 2026 there is no relaunch. peptidesciencesinc.com is unaffiliated with the original company and is on registrar hold.
Lot number, test date, the testing lab's name, HPLC purity with the chromatogram, and observed versus expected mass from mass spectrometry. Ideally it also shows endotoxin, water and heavy-metal results.
No. HPLC measures how clean the main peak is. It doesn't confirm identity or measure total peptide content. In one 2019 study, peptides reported at over 98% HPLC purity contained 20% and 43% w/w undeclared mannitol.
No. The July vote was a recommendation on pharmacy compounding. The October 28 HHS policy covers prescription compounding by licensed 503A pharmacies only. Neither covers research-use-only sales or authorizes human use.
Drafted with AI assistance and fact-checked against the cited sources by The ProGrade Research Desk. See our editorial policy and sourcing policy. Spot an error? Report it.
