Honest ratings for research peptide suppliers
A plain-English buyer's guide for labs placing an order. We read each supplier's certificates, policies and prices, run them through one published formula, and give every supplier a star rating you can trace back to the facts.
Editorial ratings, not user reviews. Every supplier listed sells materials labeled for laboratory research use only.
Our picks
Each pick is simply the highest-rated supplier that qualifies. No hand-picking, no sponsorship.
Core Peptides#1 of 49 · corepeptides.com
Peptide Perfection#17 of 49 · peptideperfection.comCore Peptides#1 of 49 · corepeptides.comTop 10 right now
| # | Supplier | Our rating | Testing | Open COAs | Per-lot | Ref. price | Based | |
|---|---|---|---|---|---|---|---|---|
| Best overall · October 2026 | ||||||||
| 1 | Core Peptidescorepeptides.com | 3.8/5 | Yes | Yes | Yes | $52 | US | ReviewVisit site |
| 2 |  Paramount Peptidesparamountpeptides.com | 3.7/5 | Yes | Yes | Yes | — | US | ReviewVisit site |
| 3 |  Koi Peptideskoipeptides.com | 3.6/5 | Yes | Yes | Yes | — | US | ReviewVisit site |
| 4 | Sports Technology Labssportstechnologylabs.com | 3.6/5 | Yes | Yes | Not verified | $54.99 | US | ReviewVisit site |
| 5 | Ascension Peptidesascensionpeptides.com | 3.5/5 | Yes | Yes | Yes | — | US | ReviewVisit site |
| 6 |  Licensed Peptideslicensedpeptides.com | 3.5/5 | Yes | Yes | Yes | — | US | ReviewVisit site |
| Best budget | ||||||||
| 7 | Alpha Labs Peptidesgoalphalabs.com | 3.4/5 | Yes | Yes | Not verified | $20.99 | US | ReviewVisit site |
| 8 |  Evolve Peptidesevolvepeptides.com | 3.4/5 | Yes | Yes | Yes | $39.90 | US | ReviewVisit site |
| 9 |  BioLongevity Labsbiolongevitylabs.com | 3.3/5 | Yes | Yes | Yes | — | US | ReviewVisit site |
| 10 |  Biotech Peptidesbiotechpeptides.com | 3.3/5 | Yes | Yes | Yes | $52 | US | ReviewVisit site |
Editorial rating, not user reviews. Stars are the weighted factor score divided by 20. Reference price = the supplier's listed price for BPC-157, 5 mg, where a like-for-like listing exists.
All 49 rated suppliers Put two side by side
Best for your situation
Prefilled peptide pens
Peptide Perfection · top pick3.2/541 qualify
US-based suppliers
Core Peptides · top pick3.8/531 qualify
Suppliers with public certificates of analysis
Core Peptides · top pick3.8/521 qualify
Lot-level third-party testing
Core Peptides · top pick3.8/58 qualify
Budget-priced suppliers
Alpha Labs Peptides · top pick3.4/514 qualify
Suppliers that ship internationally
Koi Peptides · top pick3.6/5
What goes into a rating
Quality · 30%
Independent testing, public lot certificates, named laboratory.
Trust · 35%
A findable company, years in business, clean public record.
Value · 15%
Listed prices against the field, free-shipping threshold.
Experience · 20%
Payment options, dispatch times, returns, range of formats.
Ask for the lot, not the brochure
The best-rated suppliers post a certificate for each production lot, signed by a laboratory you can look up, and let you read it before checkout. A single undated "example" certificate, or one that only arrives after you pay, earns far fewer points on the heaviest factor.
Reading a lab report in five minutes · Suppliers with per-lot testing
Right now 7 of the suppliers we track have a public FDA warning letter and 8 have shut down. All of them are listed with dates and source links.
See who to avoidBefore you order anywhere
Make sure the company exists
A street address, a phone line and a founding year cost a real business nothing. Suppliers that offer only a web form and a first name tend to be the ones that vanish, which is why we count these details toward Trust.
Know what you are buying
Everything these suppliers sell is labeled for laboratory research use only. We rate the paperwork, the pricing and the service. We do not discuss any other use, and neither should the supplier.
More rated suppliers
Pure Peptide Labs3.3/5US · independently tested · open certificates
Simple Peptide3.3/5US · independently tested
Alpha Peptides3.3/5US · independently tested · open certificatesBlue Sky Peptide3.3/5US · independently tested · open certificates
Nexaph3.3/5independently tested · open certificatesBuyer guides
Understanding Research Peptide Prices: How to Compare Like for Like (October 2026)
Research Peptide Supplier Return Policies Compared (October 2026)
Research Peptide Supplier Shipping Policies Compared (October 2026)
Reading a Peptide Lab Report in Five Minutes: A First-Time Buyer's Walkthrough (October 2026)
Questions buyers ask
What do the stars on Rated Peptides mean?
Each supplier is rated out of five stars. Behind the stars is a 0–100 score built from six checkable factors: testing and certificates (30%), track record (20%), transparency (15%), pricing (15%), catalog (10%) and ordering and service (10%). Divide the score by 20 and you have the star rating. The full recipe is on the methodology page.
Are the ratings based on customer reviews?
No. Every star on this site is an editorial rating produced by our formula from facts on the supplier's own pages and in public records. We do not gather customer reviews, we do not show them, and we do not add review markup to any page.
What should a first-time lab buyer check before ordering?
Open the supplier's certificate of analysis for the exact lot you would receive, confirm an independent laboratory is named on it, and make sure you can read it before paying. That one habit filters out most of the suppliers that end up on our avoid list.
How current are the ratings?
Supplier facts are re-checked on a rolling schedule and every page is rebuilt when the dataset changes. The month printed on a page is the month of the last rebuild.
Do suppliers pay to be rated well?
No. Some links to suppliers may be referral links that pay us a commission if you order. That never touches the formula, which is applied the same way to every supplier. The details are on our disclosure page.