Pentadeca arginate (PDA) vs BPC-157: what the research shows
Two closely related peptides — with different regulatory histories and a thin human evidence base for both.
TL;DR
- Pentadeca arginate (PDA) is a synthetic analog of the BPC-157 sequence with an added arginate salt group intended to improve stability.
- BPC-157 was placed in FDA Category 2 in 2023, and FDA removed it from Category 2 on April 22, 2026. FDA's advisory committee voted in July 2026 to recommend it for the 503A bulks list, and FDA's final decision is pending. Halftime Health protocols are prescribed by licensed physicians and prepared by licensed 503A compounding pharmacies. Compounded drugs are not FDA-approved and have not been evaluated by FDA for safety or effectiveness.
- Human evidence is thin for both. Most published research is on BPC-157 in rodents, not on PDA in humans.
What it is
PDA stands for pentadeca arginate. "Pentadeca" means 15 amino acids — the same length as BPC-157 — and "arginate" refers to a salt of the amino acid arginine added to the molecule. The idea behind PDA is to take a sequence closely related to BPC-157 and pair it with a chemical tweak intended to improve stability in compounding (Sikiric et al., 2005). BPC-157 was placed on the FDA's Category 2 list in 2023. FDA removed it from Category 2 on April 22, 2026, after its nomination was withdrawn. FDA's final decision on adding it to the Section 503A bulks list is pending as of September 2026 (FDA 503A Bulks List).
How it works
Think of BPC-157 as the parent recipe and PDA as a slightly different version of the same dish, salted differently to hold its shape longer in a hot pan. The underlying flavor — the proposed gut and tissue-repair signaling — is similar in concept. Whether it cooks the same way in human bodies is a separate question the published evidence has not answered yet.
Who asks about it
People come to this topic after they see PDA and BPC-157 named together. Many assume the two are interchangeable. They are related, but they are not the same compound, and they do not have the same evidence base.
PDA and BPC-157 side by side
- Structure. BPC-157 is a 15-amino-acid sequence. PDA is modeled on that sequence, with an added arginate salt group intended to improve stability.
- What the research shows. BPC-157 has a large preclinical literature, mostly in rodents (Sikiric et al., 2005). PDA has little published research of its own. Interest in PDA is largely extrapolated from the BPC-157 literature.
- What the research does not show. Neither compound has robust randomized human trials. The published literature does not establish that PDA and BPC-157 act the same way in people.
- Regulatory status. As of September 2026, FDA has not made a final decision on BPC-157. At its July 23–24, 2026 meeting, FDA's Pharmacy Compounding Advisory Committee voted 8 yes, 6 no, and 1 abstention to recommend adding BPC-157 to the Section 503A bulk drug substances list. The committee is advisory, and formal addition to the list requires further FDA action. Pentadeca arginate is not FDA-approved as a finished drug.
What the research says
The bulk of the published evidence is on BPC-157 in rodents — not on PDA in humans. PDA's specific human evidence base is thin. Interest in PDA rests on BPC-157's preclinical data and on stability assumptions, not on Phase 3 trial results in PDA itself. About 1 in 10 compounds that look promising in animals end up showing the same effect in human trials, on average across drug categories — a base rate that applies to PDA's underlying premise.
What to know before considering it
Side-effect data is limited for both compounds. Any compounded peptide requires a valid prescription and a licensed physician evaluation. Halftime Health protocols are prescribed by licensed physicians and prepared by licensed 503A compounding pharmacies. Compounded drugs are not FDA-approved and have not been evaluated by FDA for safety or effectiveness.
The Halftime POV
PDA and BPC-157 are close relatives with a shared research line. Neither yet has a strong human evidence base, and we describe both that way.
Related reading:
- Why BPC-157 animal studies don't automatically translate to humans
- BPC-157 availability in 2026: where things actually stand
- How to choose a quality peptide compounding pharmacy: the quality signals
FAQ
Q: What is pentadeca arginate? A: Pentadeca arginate (PDA) is a synthetic peptide modeled on the BPC-157 sequence with an added arginate salt group intended to improve stability.
Q: Is PDA the same as BPC-157? A: No. They share a closely related amino acid sequence and the same parent research line, but they are different compounds. BPC-157 was placed in FDA Category 2 in 2023. FDA removed BPC-157 from Category 2 on April 22, 2026, after its nomination was withdrawn. As of September 2026, FDA has not made a final decision on BPC-157. At its July 23–24, 2026 meeting, FDA's Pharmacy Compounding Advisory Committee voted 8 yes, 6 no, and 1 abstention to recommend adding BPC-157 to the Section 503A bulk drug substances list. The committee is advisory, and formal addition to the list requires further FDA action. Halftime Health protocols are prescribed by licensed physicians and prepared by licensed 503A compounding pharmacies. Compounded drugs are not FDA-approved and have not been evaluated by FDA for safety or effectiveness.
Q: Is PDA FDA-approved? A: No. Pentadeca arginate is not FDA-approved as a finished drug.
Q: Where is the human research? A: Human clinical evidence on PDA specifically is limited. The interest is largely extrapolated from BPC-157 rodent literature, which is itself thin in humans. Patients should set expectations accordingly.
Disclaimer
BPC-157 is discussed in this article as the parent sequence of pentadeca arginate (PDA). As of September 2026, FDA has not made a final decision on BPC-157. At its July 23–24, 2026 meeting, FDA's Pharmacy Compounding Advisory Committee voted 8 yes, 6 no, and 1 abstention to recommend adding BPC-157 to the Section 503A bulk drug substances list. The committee is advisory, and formal addition to the list requires further FDA action. Pentadeca arginate itself is not FDA-approved as a finished drug. This article is educational and is not medical advice. Halftime Health only prescribes through licensed physicians in states where our partner physicians are credentialed.
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Sources
This article discusses compounds whose FDA compounding status has been under review (see our FDA categorization explainer). Halftime Health protocols are prescribed by licensed physicians and prepared by licensed 503A compounding pharmacies. Compounded drugs are not FDA-approved and have not been evaluated by FDA for safety or effectiveness. This article is provided for educational purposes only and does not constitute medical advice or an offer to sell.
Frequently asked questions
What is pentadeca arginate?
Pentadeca arginate (PDA) is a synthetic peptide modeled on the BPC-157 sequence with an added arginate salt group intended to improve stability.
Is PDA the same as BPC-157?
No. They share a closely related amino acid sequence and the same parent research line, but they are different compounds. BPC-157 was placed in FDA Category 2 in 2023. FDA removed BPC-157 from Category 2 on April 22, 2026, after its nomination was withdrawn. As of September 2026, FDA has not made a final decision on BPC-157. At its July 23–24, 2026 meeting, FDA's Pharmacy Compounding Advisory Committee voted 8 yes, 6 no, and 1 abstention to recommend adding BPC-157 to the Section 503A bulk drug substances list. The committee is advisory, and formal addition to the list requires further FDA action. Halftime Health protocols are prescribed by licensed physicians and prepared by licensed 503A compounding pharmacies. Compounded drugs are not FDA-approved and have not been evaluated by FDA for safety or effectiveness.
Is PDA FDA-approved?
No. Pentadeca arginate is not FDA-approved as a finished drug.
Where is the human research?
Human clinical evidence on PDA specifically is limited. The interest is largely extrapolated from BPC-157 rodent literature, which is itself thin in humans. Patients should set expectations accordingly.
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