Cortagen is a synthetic tetrapeptide — Ala-Glu-Asp-Pro (AEDP), roughly 430 Da, molecular formula C17H26N4O9 — that Vladimir Khavinson's St. Petersburg group derived from amino-acid analysis of Cortexin, a porcine cerebral-cortex extract. That origin story is exactly where most buyers go wrong: Cortexin is the extract with decades of Russian clinical use, while Cortagen is the short synthetic analog whose published record is a handful of small animal and in-vitro studies. If you are shopping for one, you should be sure you are not paying for the other.
This guide covers what Cortagen typically costs on the research market, how to verify a certificate of analysis for a peptide this simple, and — most importantly — how to confirm you are actually buying the AEDP tetrapeptide and not a mislabeled cortex extract or a different Khavinson peptide. Cortagen is niche enough that vendor quality varies a lot, so knowing what a real COA looks like is the single most useful skill here.
Research-context information only. Cortagen is a research peptide. Protocols, doses, and reactions reported below come from published research and self-reported community sources. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.
Affiliate disclosure: Some links below route to vendor partners, and we may earn a commission if you buy through them at no extra cost to you. That never changes what we report about a vendor's COA, pricing, or track record. All products discussed are research chemicals labeled "not for human consumption."
This is not a ranked vendor list — for that, see our Best Cortagen Vendors comparison. This guide teaches you how to evaluate any vendor yourself.
Understanding Cortagen Pricing
Cortagen is sold as a lyophilized (freeze-dried) powder in sealed glass vials. Because it is a niche Khavinson bioregulator rather than a mainstream peptide, fewer vendors stock it, and prices are less compressed than they are for high-volume compounds like BPC-157 or semaglutide. That means two things: per-mg pricing swings more from vendor to vendor, and vial-size selection matters less than simply finding a reputable seller with a real COA.
Current Market Pricing (2026)
The ranges below reflect typical research-market listings, not any single vendor's exact number (which goes stale). For live per-mg pricing, use the comparison pages linked under each table.
| Vial Size | Typical Price Range | Price Per mg | Best For |
|---|---|---|---|
| 5 mg | $18-45 | $3.60-9/mg | Tolerance/identity testing |
| 10 mg | $25-60 | $2.50-6/mg | Most common single-vial purchase |
| 20 mg | $40-100 | $2-5/mg | Longer courses, better per-mg value |
The pattern is the usual one: the larger vial lowers the per-mg cost because base synthesis cost is nearly flat, but the spread is smaller than it is for cheaper peptides — the bigger variable for Cortagen is which vendor, not which vial.
Cost Per Course at Reported Protocols
Community-reported Cortagen courses are typically short (roughly 10-20 days), and published animal work used small doses, so total peptide per course is modest. The figures below are illustrative math on the vial pricing above, not a dosing recommendation.
| Reported course length | Total mg (illustrative) | Cost (10mg vial route) | Cost (20mg vial route) |
|---|---|---|---|
| Short course (~10 days) | ~10 mg | $25-60 | $40-100 (with leftover) |
| Standard course (~20 days) | ~20 mg | $50-120 | $40-100 |
| Two courses / year | ~40 mg | $100-240 | $80-200 |
For current vendor-specific pricing with exact $/mg breakdowns, see our Best Cortagen Vendors comparison.
How to Verify Cortagen Quality
Cortagen is a four-amino-acid peptide with molecular formula C17H26N4O9 and a molecular weight of about 430 Da. It is short, simple, and cheap to synthesize — which means a legitimate certificate of analysis is easy for any competent vendor to produce, and the absence of one is a red flag rather than an excuse. The bigger verification challenge with Cortagen is not purity; it is identity. You want to confirm the vial contains the AEDP tetrapeptide and not a mislabeled cortex product.
What a COA (Certificate of Analysis) Should Include
Identity Confirmation
- Mass spectrometry confirming the correct molecular weight (about 430 Da; molecular formula C17H26N4O9)
- Amino-acid sequence verification matching Ala-Glu-Asp-Pro (AEDP)
Purity Testing
- HPLC purity — look for 98%+ purity
- The chromatogram should show a single dominant peak with minimal impurities
Contamination Testing
- Endotoxin levels (bacterial contamination)
- Residual solvent analysis (acetonitrile, TFA)
- Heavy-metals screening
How to Verify a COA Is Legitimate
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Check the testing lab — Reputable third-party labs include Janoshik Analytical, MZ Biolabs, and Colmaric Analyticals. Avoid vendors who only show "in-house" testing.
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Verify on the lab's website — Janoshik COAs carry a task number you can look up directly at janoshik.com.
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Check the date — A COA should be recent (within about 6 months) and not a years-old document reused across batches.
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Match the batch — The batch/lot number on the COA should match what is printed on your vial.
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Look for the original PDF — Full PDFs with lab letterhead and signatures are much harder to fake than a cropped screenshot.
Red Flags to Avoid
- No COA available — inexcusable for a peptide this cheap to synthesize and test
- Only in-house testing — self-reported purity numbers are meaningless
- Product sold simply as "Cortexin" or "cortex peptide" — that is the extract or an unspecified product, not the AEDP tetrapeptide; confirm the sequence
- A COA whose mass does not match ~430 Da — you may be looking at a different cortex peptide or the wrong compound entirely
- No contact information — legitimate vendors have real customer service
- No return or reship policy — reputable vendors stand behind their products
