Where to Buy P21 in 2026: 1 Lab-Tested Seller, From $8.10/mg With a Coupon Code
Where to buy P21: PepAssess lists P21 at 3 vendors. As of November 12, 2026, the lowest price with a coupon code is $7.86/mg buying 2 vials at Ps Peptides (code PEPASSESS); the median across all sellers is $9.99/mg. Vendors are ranked by Evidence Score.
Prices and codes updated November 12, 2026 · re-checked every night
Published papers describe it as a tetrapeptide with an added adamantyl glycine, and also as Ac-DGGLAG-NH2.
Learn more about P21 (P021) from the published research: Alzheimer's Research & Therapy (2017) · Journal of Alzheimer's Disease (2021) · ClinicalTrials.gov (NIH)
The compounds listed on this page are for research purposes only, not for human consumption.
P21 reconstitution calculator →
P21 coupon codes
Every P21 coupon code
5 P21 sellers with a confirmed code — highest Evidence Score first.
| Shop | Score | Vial with code | Per mg | Per mg with code | vs typical | Code discount | Code | |
|---|---|---|---|---|---|---|---|---|
| Disguised Alpha | 83score | — | — | — | — | 10% off | ShopShop ↗ | |
| Ps Peptides | 77score | 10 mg vial $78.56 with code | $9.00/mg | $8.10/mg with code | — | 10% off | ShopShop ↗ | |
| GenX Peptides | 68score | — | — | — | — | 15% off | ShopShop ↗ | |
| VMAX Peptides | 63score | 10 mg vial $89.91 with code | $9.99/mg | $8.99/mg with code | — | 10% off | ShopShop ↗ | |
| Peptuvia | 63score | 10 mg vial $133.20 with code | $14.80/mg | $13.32/mg with code | — | 10% off | ShopShop ↗ |
Where to buy P21: the short answer
What is the lowest P21 price with a coupon code?
As of November 12, 2026, the lowest P21 price PepAssess found with a coupon code is at Ps Peptides: $7.86 per mg buying 2 vials with code PEPASSESS (10% off; $9.00 per mg before the code). Prices are re-checked every night. Ps Peptides coupon code
What is the best P21 coupon code?
As of November 12, 2026, the biggest P21 coupon code PepAssess has confirmed is PEPASSESS for 10% off at Ps Peptides, which brings it to $7.86 per mg. PepAssess lists each code with its discount and the seller's Evidence Score, based on lab reports confirmed with the testing labs. Ps Peptides coupon code
Where can I buy lab-tested P21?
As of November 12, 2026, PepAssess lists 3 online vendors selling P21. 1 of them publish a P21 lab report that the testing lab confirmed on its own records, and 1 of those cover both purity (HPLC and mass spec) and toxicity (endotoxin or sterility). The highest-scoring vendors with a lab-confirmed P21 report are Disguised Alpha (83/100). Compare all 3 P21 vendors on PepAssess
What is the best P21 vendor?
PepAssess ranks P21 vendors by Evidence Score (0–100): what each vendor documents — lab reports confirmed by the labs, how often it tests, business transparency and buyer protection. As of November 12, 2026, the top-scoring P21 vendors are Disguised Alpha (83/100), GenX Peptides (68/100) and VMAX Peptides (63/100) — 1 of them with a lab-confirmed P21 report.
What is the cheapest P21 per mg?
The lowest P21 price PepAssess found is $9.99/mg at VMAX Peptides; the median across vendors is $9.99/mg (as of November 12, 2026). Prices come from each vendor's own store and exclude shipping and discounts.
P21 cost per week
What one 10 mg vial of P21 costs per week of research, at the lowest one-vial price with a coupon code: $80.99 at Ps Peptides (code PEPASSESS, $8.10/mg), as of November 12, 2026.
| One vial used over | Cost per week |
|---|---|
| 2 weeks | $40.50 |
| 4 weeks | $20.25 |
| 8 weeks | $10.12 |
Lab-confirmed P21 reports
1 of 3 sellers publish a P21 lab report. 1 have one the testing lab confirmed on its own records; 1 of those cover both purity (HPLC + mass-spec identity) and toxicity (endotoxin or sterility). Those covering both are listed first, then by Evidence Score.
| Vendor | Purity | Toxicity | Latest | Per mg | Code | Score | |
|---|---|---|---|---|---|---|---|
 Disguised Alpha | Purity ✓↗ | Toxicity ✓↗ | Aug 2026 | — | 10% off | 83score | ShopShop ↗ |
| # | Vendor | Doses (mg) | From | Best $/mg | Evidence score ⓘ | |
|---|---|---|---|---|---|---|
| 1 | — | — | — | 83score | Shop | |
| 2 | 5 | — | — | 68score | Shop | |
| 3 | 10 | from $99.90 ↗ | $9.99/mg | 63score | Shop |
Prices come from each vendor's own public store data and may exclude shipping, discounts or bulk pricing. Research-use products; not medical advice.
About P21 (P021)
What it is
Published papers describe it as a tetrapeptide with an added adamantyl glycine, and also as Ac-DGGLAG-NH2. Nearly all published work is in mice and cells. The published research is in mice.
How it works
- Mimics the neurotrophic (nerve-supporting) activity of CNTF without being the whole protein.
- In mice it increased markers of neuroplasticity, including phosphorylated CREB and BDNF.
- Was reported to boost neurogenesis (new nerve cell formation) in mouse brain.
The compounds listed on this page are for research purposes only, not for human consumption. Not medical advice.
P21: more questions people ask
Which P21 vendors have lab reports confirmed by the testing lab?
1 as of November 12, 2026. Those whose confirmed reports cover both purity and toxicity: Disguised Alpha. PepAssess matches each report to the issuing lab's own public record, not the vendor's copy.
How can I tell if a P21 certificate of analysis (COA) is real?
Look the report up in the testing lab's own records — most labs that test peptides publish a lookup by report ID, QR code or lot number. PepAssess does this for every P21 report it finds: as of November 12, 2026, 1 of the 1 sellers publishing a P21 report had one the lab confirmed.
How much does a vial of P21 cost?
As of November 12, 2026, a 5 mg vial of P21 costs a median $112 across the 33 sellers PepAssess found with one in stock (lowest $54.99); a 10 mg vial, a median $98.06 across 18 sellers (lowest $50). Each seller's lowest in-stock price for that size counts once; prices come from each seller's own store and exclude shipping and discounts.
How do I know if a P21 seller is legit?
Check what the seller can show. As of November 12, 2026, PepAssess checks every P21 seller for three things: a P21 lab report that the testing lab confirms on its own records (1 of 3), card payments, which let you dispute a charge (3 of 3), and a published street address — not a mailbox or registered agent (2 of 3). Each seller's PepAssess profile shows which of these it has.
Are there P21 coupon codes?
Yes. PepAssess lists coupon codes for 3 vendors selling P21: Disguised Alpha: REF-4GN8-3QTN (10% off), GenX Peptides: PEPASSESS (15% off) and VMAX Peptides: pepassess10 (10% off).