Independent analysis · No paid rankings

Know exactly
who to trust.

PeptideComparison.io objectively scores every vendor on COA quality, price, reviews, shipping, and availability. Covering BPC-157, Retatrutide, GHK-Cu, NAD+, GLOW/KLOW blends, and GLP-1 telehealth — all in one place.

See rankings How we score →
13
Vendors ranked
5
Criteria scored
2×
COA weight
Free
Always free to use
How it works

Scoring you can verify

Every score is built from five transparent criteria, weighted to reflect what actually matters for safety and quality.

01
Price
Price per mg for comparable compounds, adjusted for included services (consultation, coaching, shipping).
Weight: 1×
02
Reviews
Aggregated from Trustpilot, Reddit r/Peptides, community forums. Weighted by volume and recency.
Weight: 1×
03
Shipping speed
Verified average US shipping time from order to delivery. Domestic vendors scored higher.
Weight: 1×
04
Availability
Catalog breadth, stock consistency, and whether key compounds are reliably in stock.
Weight: 1×
05
COA quality
Third-party HPLC and mass spec availability, lot traceability, public access, and methodology rigor.
Weight: 2× — most important
Compounds covered

What we rank

From standalone peptides to multi-peptide blends and GLP-1 telehealth — all covered in one place.

GHK-Cu (Copper Peptide)
A naturally occurring copper-binding tripeptide (Gly-His-Lys + Cu²⁺). Studied for roles in collagen synthesis, skin remodeling, fibroblast activity, and antioxidant signaling. Available as injectable, topical, or tablet. The base ingredient in both GLOW and KLOW blends.
MW: 401.91 g/mol · CAS: 89030-95-5
GLOW Blend
A three-peptide research blend: BPC-157 + TB-500 + GHK-Cu. Studied for combined effects on cellular repair (BPC-157), tissue remodeling and cell migration (TB-500), and extracellular matrix regeneration and collagen signaling (GHK-Cu). Typically available as a 60mg blended vial. Paramount Peptides and Swiss Chems are the top-rated vendors currently carrying it.
3-peptide blend · ~60mg total · for research use only
KLOW Blend
A four-peptide research blend: BPC-157 + TB-500 + GHK-Cu + KPV. KLOW extends GLOW by adding KPV — a tripeptide fragment of α-MSH studied for anti-inflammatory and epithelial integrity signaling. Better suited for research protocols where inflammation modulation is a primary variable. Typically ~80mg blended vial. Paramount Peptides and Swiss Chems are currently the highest-rated vendors stocking KLOW.
4-peptide blend · ~80mg total · KPV adds anti-inflammatory dimension
BPC-157
15-amino acid synthetic peptide derived from a gastric protective protein. Studied for angiogenic signaling, fibroblast activity, and tissue repair. Core ingredient in both GLOW and KLOW blends. One of the most-researched peptides on the market.
Body Protection Compound-157 · 15 AA sequence
TB-500
Synthetic fragment of Thymosin Beta-4, studied for actin regulation, cellular migration, and wound-related signaling. Works alongside BPC-157 in GLOW/KLOW to support structural tissue response and systemic regeneration pathways.
Thymosin Beta-4 fragment · Actin modulation
Retatrutide (LY3437943)
A 39-amino acid synthetic triple-agonist peptide — often called "triple G" — that simultaneously targets GLP-1, GIP, and glucagon receptors. The most advanced next-generation metabolic research compound available, studied for coordinated multi-pathway energy regulation. Phase 2 clinical trial data showed significantly greater metabolic endpoints than single or dual agonists. Requires rigorous third-party mass spec verification (MW ~4683 Da) to confirm identity — purity testing alone is insufficient.
Triple GLP-1 / GIP / Glucagon agonist · MW ~4683 Da · Research Use Only · Verify MS identity
NAD+ (Nicotinamide Adenine Dinucleotide)
A ubiquitous coenzyme present in every living cell, essential for cellular energy metabolism, DNA repair, and sirtuin-mediated stress responses. NAD+ levels decline with age. In research contexts it is studied for roles in mitochondrial biogenesis, PARP-dependent DNA repair, and metabolic homeostasis. Available as lyophilized powder; requires careful COA verification including endotoxin (LPS) testing due to stability sensitivity.
Research Use Only · Requires endotoxin-free COA · Store at 4°C
Semaglutide / Tirzepatide
GLP-1 receptor agonists (and in tirzepatide's case, dual GIP/GLP-1). Require a prescription through a licensed telehealth provider. Compared across Hims, Ro, Eden, AgelessRx, and Noom on price, support, COA transparency, and shipping.
Prescription only · Telehealth vendors only
Rankings

2026 vendor comparison

Click any card to expand full details including pricing, COA standard, shipping, and available compounds.

Category:
Peptide:
Sort:
COA quality is weighted 2× in the overall score — the single most important trust signal. Learn how to read a COA →
Methodology

How scores are calculated

Each vendor is scored 1–10 on five criteria. COA quality is weighted double because purity verification is the only reliable safety signal in an unregulated market.
Price
1 / 6 total
Reviews
1 / 6 total
Shipping speed
1 / 6 total
Availability
1 / 6 total
COA quality ×2
2 / 6 total
Score = (Price + Reviews + Shipping + Availability + (COA × 2)) ÷ 6

All scores are independently researched and updated monthly. We check Trustpilot, Reddit, and community forums for review data. Price data is verified by checking vendor checkout flows directly.

COA quality is evaluated on four sub-criteria: whether testing is third-party (not in-house), whether HPLC chromatograms are publicly available, whether mass spectrometry confirms compound identity, and whether lot numbers are traceable to the specific vial.

PeptideComparison scores are independently researched. Our scoring methodology and individual scores are determined independently of any commercial relationships.

We reassess vendor scores monthly and immediately if significant community reports emerge. Vendors that shut down or receive credible fraud reports are removed within 24 hours.

About & disclaimer

Built for informed buyers

Everything you need to know about how this site works and its limitations.

Medical & legal disclaimer

Nothing on PeptideComparison constitutes medical advice, diagnosis, or treatment. Research peptides are sold for research purposes only and are not intended for human consumption. GLP-1 medications require a prescription from a licensed healthcare provider. Always consult a qualified medical professional before starting any new treatment. PeptideComparison does not endorse, prescribe, or recommend any specific treatment protocol.

Data accuracy

Vendor scores, pricing, and availability are updated monthly but may not reflect real-time changes. The peptide vendor market is volatile — vendors can change ownership, quality standards, or cease operations without notice. Always verify current information directly with the vendor before purchasing. If you discover inaccurate information, contact us.

google-site-verification=swOaoZ2iFQHDBvA17LR-VqlULE-KE12gEIyTdX9TL38