Pentadeca Arginate (PDA)
Also known as: BPC-157 Arginine Salt, BPC-157 Arginate, Pentadecapeptide Arginate
What Is PDA?
Pentadeca Arginate (PDA) is marketed as a distinct compound, but the chemistry tells a simpler story: PDA is the L-arginine salt form of BPC-157. It contains the exact same 15-amino-acid peptide sequence (GEPPPGKPADDAGLV) as standard BPC-157, with arginine as the counter-ion instead of acetate.
The preferred form described in the patent (WO2014142764A1, inventor Rudolf Ručman, assignee Diagen d.o.o., filed 2013, granted as US9850282B2 in 2017) is the di-L-arginine salt. Ručman was a longtime collaborator of Predrag Sikirić, the Zagreb researcher behind virtually all BPC-157 research.
The Evidence Problem
After extensive searching of PubMed, Google Scholar, and all major scientific databases, no peer-reviewed journal article has ever been published comparing BPC-157 arginate vs. BPC-157 acetate in any experimental model. No pharmacokinetic study. No stability comparison. No animal study. No human study. Nothing.
The only source for arginate-specific data is the patent itself — which is not peer-reviewed research. Patents are legal documents designed to establish intellectual property claims, not scientific evidence designed to establish therapeutic efficacy. They are not subject to peer review, statistical scrutiny, or reproducibility requirements.
All ~100+ published BPC-157 studies used the standard acetate/free form, not the arginate salt.
Vendor Claims vs. Available Evidence
| What vendors claim | What the evidence shows |
|---|---|
| ”99.9% oral bioavailability” | Biologically implausible and completely unsubstantiated. No oral peptide achieves this. Even semaglutide with patented SNAC technology achieves only 0.8%. |
| ”Superior bioavailability to BPC-157” | Zero published comparative data exists — not in animals, not in humans, not in cell cultures |
| ”FDA-designated regenerative agent” | Misleading — The FDA has not approved PDA for any use. The underlying peptide is identical to Category 2 BPC-157 |
| ”Backed by research” | All cited research used standard BPC-157, not the arginate salt specifically |
| ”Enhanced stability” | Theoretically plausible based on general arginine salt chemistry (PMC10702853), but never validated for this specific peptide |
| ”Legal alternative to BPC-157” | The peptide sequence is identical. Legal experts note that salt form changes do not make a prohibited peptide legal |
The “99.9% Bioavailability” Claim Deserves Special Attention
This claim, which appears prominently in PDA marketing, is worth examining carefully. In pharmacology, 99.9% oral bioavailability would mean that virtually every molecule you swallow reaches systemic circulation unchanged. For context:
- Acetaminophen (a small, stable drug molecule): ~85% oral bioavailability
- Semaglutide with SNAC: ~0.8% oral bioavailability
- Insulin (peptide, no absorption enhancer): ~0% oral bioavailability
For a 15-amino-acid peptide to achieve 99.9% oral bioavailability, it would need to completely survive gastric acid, pepsin, pancreatic proteases, brush border peptidases, first-pass hepatic metabolism, and cross the intestinal epithelium intact — all at near-perfect efficiency. No peptide in pharmaceutical history has achieved this. The claim is not merely unsupported; it defies basic pharmacological principles.
What PDA Actually Has Going For It
To be fair, the theoretical rationale for arginine salts is not baseless. Arginine is a well-known excipient in pharmaceutical science that can improve protein stability through multiple mechanisms: guanidinium-mediated suppression of aggregation, preferential interaction with protein surfaces, and potential effects on crystalline properties. A 2023 review in Pharmaceutics (PMC10702853) documents these effects for proteins generally.
But documenting that arginine stabilizes proteins in general is very different from proving that an arginine salt of BPC-157 specifically has improved oral bioavailability. That specific claim requires specific evidence, and that evidence does not exist.
Safety Profile
No safety data exists for PDA specifically. The safety profile would presumably mirror BPC-157 (which itself has minimal human data — see our BPC-157 profile). The addition of arginine as a counter-ion is unlikely to introduce new safety concerns at the doses used in supplements, as arginine itself has GRAS status and is consumed daily in food.
Legal and Regulatory Status
PDA occupies an ambiguous legal space. Vendors market it as a dietary supplement distinct from BPC-157, but the peptide sequence is identical. The FDA has not separately evaluated PDA. Legal experts specializing in FDA law (Holt Law, Frier Levitt) have noted that changing the salt form of a prohibited substance does not create a new, legal substance — the active ingredient remains the same.
If the FDA were to challenge a PDA product, the vendor’s defense would essentially be: “Our product is legally distinct because we used a different salt form of the same molecule that the FDA has prohibited.” Whether that argument would survive legal scrutiny is untested.
The Bottom Line
PDA is a marketing innovation, not a scientific one. It is the same peptide as BPC-157 — same sequence, same molecular mechanism, same evidence base (which is entirely animal-derived). The arginine salt form may provide modest stability improvements, but the extraordinary bioavailability claims made by vendors have zero published evidence behind them. If you’re considering PDA because you believe it’s a proven, more effective version of BPC-157, you should know that the “proof” consists entirely of a patent filing and vendor marketing copy.
Every evidence-based assessment that applies to BPC-157 — the lack of human trials, the unproven oral bioavailability, the single-lab-group research problem — applies equally to PDA. It’s the same compound in a different wrapper, sold at a premium based on claims that have never been tested.