Testing intelligence for supplement, peptide, and compounding teams. A monthly briefing from Prodigy Labs.
Welcome to the first issue of On Spec. Once a month I will send you the testing and quality signal that actually matters for supplement, peptide, and compounding teams, with sources so you can check my work. Here is what earned your attention this month.
The Big Read — The FDA's peptide signal lands on your COA
On July 23 and 24, the FDA's Pharmacy Compounding Advisory Committee reviewed seven nominated peptides for the 503A bulk substances list. The agency's own review staff recommended against adding all seven. The committee split from staff and voted to recommend six: BPC-157, KPV, TB-500, MOTS-c, Semax, and epitalon. It declined only emideltide (DSIP).
| Peptide | FDA staff | Committee |
|---|---|---|
| BPC-157 | Against | Recommended |
| KPV | Against | Recommended |
| TB-500 | Against | Recommended |
| MOTS-c | Against | Recommended |
| Semax | Against | Recommended |
| Epitalon | Against | Recommended |
| Emideltide (DSIP) | Against | Declined |
The votes are advisory. The FDA still has to run formal rulemaking before any of these can be legally compounded, realistically eight to twelve months out, with enforcement discretion in the meantime. So nothing is settled. But the part worth reading twice is why FDA staff pushed back.
Their brief flagged nominators giving inconsistent or contradictory information about whether they were nominating the free base or the acetate salt, alongside missing impurity and endotoxin data and thin human evidence. Translate that: the government's stated objection is not ideology, it is characterization. Salt form changes the actual peptide mass a patient receives. Impurities and endotoxins are what make an injectable unsafe. Identity confirms the vial holds what the label claims.
Those are lab questions, not policy questions. And whatever the final rule says, the product is already in the market at scale, riding the same demand curve as the GLP-1 compounding crackdown. If you formulate, resell, or dispense these, the burden of proof sits with you, and it sits on the certificate of analysis: purity by HPLC, identity by an orthogonal method, counterion and content, endotoxin. That is the file that survives a regulator's question, or a customer's.
Testing Watch — Where the testing bar is moving
Amazon now requires third-party verification for supplements. Dietary supplements sold in Amazon's US store must be verified by NSF, UL, or Eurofins, confirming cGMP manufacturing, no harmful contaminants, and label accuracy. Weight loss, sexual enhancement, and sports or bodybuilding products are prioritized for added active-ingredient testing. Listings without verification by their deadline get suppressed.
New York's minor-sales restriction survives its First Amendment challenge. The Second Circuit affirmed the denial of an injunction against New York's law restricting weight loss and muscle building supplement sales to minors. Similar bills are live in other states, and retailers are watching category risk.
Verification is becoming table stakes, not a badge. Between retailer mandates and state law, documented third-party testing is shifting from a premium differentiator to a condition of shelf space. The USP Verified and NSF marks still carry buyer trust, but the floor is rising for everyone.
On the Bench — New research worth a look
The triple agonist keeps raising the ceiling. Retatrutide, a triple hormone-receptor agonist, continued to post large weight-loss figures as its trial program matured, extending the GLP-1 class into new territory. NEJM.
Omega-3s and exercise recovery. A 2026 meta-analysis found omega-3 supplementation reduced markers of exercise-induced inflammation and improved recovery in athletes. The FASEB Journal.
Protein vs creatine vs omega-3, head to head. A network meta-analysis in Nutrients compared the three for strength, endurance, and recovery in trained athletes, a useful reference when brands make comparative claims. MDPI.
New Developments — Moves in the market
Innovation is shifting to proof. Industry coverage notes new products competing less on novel ingredients and more on proof, personalization, and measurable performance, i.e. testing and verification as the pitch.
Creatine keeps expanding. Creatine continues to move into new formats and categories, including women's health and everyday wellness lines, well beyond its sports roots. NutraIngredients.
Longevity peptides keep launching ahead of the rules. New longevity peptide platforms continue to reach consumers faster than the regulatory framework can catch up, which is exactly why sourcing and identity testing matter. Longevity.Technology.
From the Lab — What we are doing about the salt-form problem
Back to the Big Read: the FDA's own objection was that nobody could say whether a peptide was the free base or the acetate salt. We run peptide identity and purity by HPLC with orthogonal confirmation. Salt-form correction is the piece the whole industry reports loosely, and we are building content reporting into the certificate itself rather than leaving you to infer active mass from a gross number. If you are formulating against these peptides, ask whoever tests them today which number they are giving you.
Send a sample → Or see peptide identity and purity pricing at prodigy-labs.com/peptide-testing-pricing.
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Prodigy Labs · 5414 Oberlin Dr, Suite 150, San Diego, CA 92121. Sources linked inline. Nothing here is medical, legal, or regulatory advice.
Note on this archived issue. Wording has been brought in line with current house style: where the issue as sent said "net peptide content", this page says "content". The measurement and the conclusion are unchanged. We retired the longer phrase because it implies a determination we do not make.