This week, two longevitydocs.™ physicians were in the room where the FDA decided the future of peptide compounding. One sits on the committee that cast the vote. The other has an evidence-based peptide framework of her own, and took the microphone to testify for it.
At Cannes 2026 (June 8-11), Dr. Jeffrey Egler, Noom's Chief Medical Officer, Noom CEO Geoff Cook, and Dr. Joshua Starbuck previewed exactly the conversation that was coming, in their panel titled "The GLP-1 & Peptide Tsunami." Dr. Egler shared new research on GLP-1 microdosing and its psychosocial effects, and Dr. Starbuck, moderating the panel, used his closing minutes to walk the room through what an eventual FDA peptide vote would and would not mean. While Dr. Elizabeth Yurth's Cannes session, "Confessions of a Longevity Doctor" with Dr. Cynthia Keller, focused on cellular medicine, she shared her deep knowledge of peptides in last year's longevitydocs.™ Peptide Mastermind. This week, she was the one standing at the microphone testifying before the very committee that Dr. Starbuck sits on.
On July 23-24, the FDA's Pharmacy Compounding Advisory Committee (PCAC) met to vote on the near-term future of compounded peptide therapy, and neither Dr. Starbuck nor Dr. Yurth was speculating from the outside back in June. Dr. Starbuck sits on that committee as a voting member, appointed for a term running through 2030 (see his official FDA committee CV and the current PCAC roster). Dr. Yurth testified before it directly, on BPC-157 specifically, one of the physician voices the committee heard before it cast its vote, per Dr. Starbuck's own account of the hearing.
As a community, longevitydocs.™ physicians are coming together to stay at the forefront of peptide understanding in practice, together. We are humbled to have such respected minds in longevity medicine as part of this community.
FDA PCAC Vote: BPC-157, KPV, TB-500, and MOTS-c Recommended for the 503A Bulks List
On Day 1 of the meeting, the committee voted to recommend BPC-157, KPV, and TB-500 for the 503A Bulk Drug Substances List, 8 to 6 with one abstention on each, and MOTS-c by a narrower 7-5 margin with two abstentions, all four against the recommendation of FDA's own scientific review staff, who had flagged unresolved questions about product characterization and gaps in the safety and efficacy data (FDA Law Blog's report from the meeting; Regulatory Focus). As of publishing, the vote is a recommendation only. It still requires FDA sign-off, and the full path to an official rule change, category reclassification followed by notice-and-comment rulemaking, typically runs several months to a year.
Dr. Starbuck laid out exactly this mechanism at Cannes, before any of it was confirmed:
Come July, everyone's saying, hey, peptides are going to be free, and pharmacy compounders are going to be able to make it rain peptides. That's not the case, and very few people are talking about this out there. The committee is voting for a recommendation that the FDA is going to have an open hearing period for, and that can last anywhere from three to twelve months before they make it official. Dr. Joshua Starbuck, Cannes 2026
He also drew a distinction that keeps getting lost in the noise: a recommendation to the Bulks List is not the same thing as a Category 1 designation, and the two mechanisms carry very different weight. And he flagged a detail worth remembering for anyone vetting a sourcing partner: 503B compounding pharmacies are federally regulated by the FDA, while 503A pharmacies are state-governed, with only a handful of states, Florida among them, enforcing materially tighter oversight of the manufacturing process.
That regulatory explainer came at the close of a longer panel, "The GLP-1 & Peptide Tsunami," moderated by Dr. Starbuck alongside Noom CEO Geoff Cook and Noom Chief Medical Officer Dr. Jeffrey Egler. The bulk of the session belonged to Egler and Cook, walking through where Noom's clinical research on GLP-1 therapy actually stands.
Dr. Jeffrey Egler Chief Medical Officer, Noom · Panelist, "The GLP-1 & Peptide Tsunami," Cannes 2026, with Geoff Cook (CEO, Noom) and Dr. Joshua Starbuck (Moderator)
Egler is double board-certified in Family Medicine and Lifestyle Medicine, with additional training in Functional Medicine and a master's degree in Spiritual Psychology. Before joining Noom as Chief Medical Officer, he was Medical Director at Next Health, held clinical leadership roles at Adventist Health and Parsley Health, and served as an Assistant Clinical Professor of Family Medicine at USC after an academic medicine fellowship at UCLA.
Key Takeaways
-
Noom's core thesis is that behavior change, not the molecule alone, determines whether GLP-1 gains hold; the biggest failure mode he sees isn't access to the drug, it's people not sustaining results after stopping it.
-
Noom's microdosing research (submitted for peer-reviewed publication) compared roughly 7,000-8,000 patients on a standard GLP-1 program to nearly 3,000 on a microdose protocol (up to about 33% of the standard maintenance dose): 8.3% weight loss at 16 weeks in the microdose cohort versus 8.6% in the standard cohort, over 95% of the full benefit, alongside a 29% reduction in side effects overall and up to 34% in matched-cohort analysis for GI-specific side effects.
-
A psychosocial survey of 5,000 GLP-1 users (2,500 on Noom's program, 2,500 using GLP-1s elsewhere) found a 68% increase in flourishing and joy measures, directly contradicting the anhedonia many clinicians worry about, and more than 90% of respondents attributed broader healthy habit changes, not just eating less, to the medication.
-
88% of surveyed users reported greater self-efficacy, and Noom is running an fMRI study with Penn examining whether reduced food noise on GLP-1s translates into broader self-control, not just less interest in eating.
-
At the one-year mark, patients who stayed engaged with Noom's companion app were twice as likely to develop interest in broader metabolic health, beyond the weight loss they originally came in for.
-
Egler was direct about where Noom stands on peptides: the company is watching the compounding space closely but is deliberately staying out of the gray market, wanting any expansion into peptides grounded in the best available safety and efficacy data rather than speed to market.
Mentioned Noom · Geoff Cook · GLP-1 microdosing · ApoB · lipoprotein(a) · Penn fMRI study
Dr. Joshua Starbuck Owner, Founder & Physician, Makena Health · FDA Pharmacy Compounding Advisory Committee · Moderator, "The GLP-1 & Peptide Tsunami," Cannes 2026
Dr. Starbuck is a board-certified internist and IFMCP-certified physician who founded Makena Health in Wailea, Hawaii in 2021, after five years as a hospitalist at Maui Memorial Medical Center. In April 2026, he was appointed to a four-year term on the FDA's Pharmacy Compounding Advisory Committee, representing internal medicine expertise. At Cannes, he stepped in at the last minute to moderate this panel after its original moderator, Dr. Steven Murphy, was unable to attend, and used his closing minutes to bring his own regulatory and clinical perspective to the room.
Key Takeaways
-
The July PCAC vote is a recommendation to add specific peptides to the 503A Bulk Drug Substances List, a different and separate mechanism from an FDA Category 1 designation.
-
A committee recommendation triggers an open hearing period that can run three to twelve months before anything becomes official; claims that peptides would be broadly legal to compound by August were circulating and are false.
-
503B compounding pharmacies are federally regulated by the FDA; 503A pharmacies are state-governed, and oversight quality varies significantly by state, Florida enforces tighter scrutiny than most.
-
Starbuck shared his own n=1 experience: chronic bilateral knee pain in his 50s resolved on one side with targeted supplementation, but the other persisted until two weeks into microdosed GLP-1 therapy (0.2-0.3mg), after which it resolved completely, consistent with emerging data on GLP-1 activity and joint-cartilage cytokine pathways.
-
His closing argument: optimism about peptide science should not come without discipline. Peptides are tools for informed, responsible clinicians, not a replacement for foundational lifestyle work, and the field is not immune to regulatory scrutiny when it moves faster than its evidence base.
-
With the FDA's public comment docket open ahead of the July hearing, Dr. Starbuck urged physicians with real clinical experience or outcome data to submit comments directly, calling it a rare moment where physician voices could actually shape the regulatory outcome.
The science behind peptide therapy is genuinely exciting, and the clinical outcomes many of us are seeing in practice are real. But optimism without discipline is how fields get the kind of culture that celebrates biological optimization while outsourcing the hard work of sleep, movement, and metabolic health. That culture is the enemy of what we're trying to build here. Dr. Joshua Starbuck, Cannes 2026
Mentioned FDA Pharmacy Compounding Advisory Committee · 503A / 503B compounding pharmacies · BPC-157 · TB-500 · KPV · MOTS-c · Makena Health · Dr. Steven Murphy
Dr. Elizabeth Yurth: From the Stage to the FDA Hearing Room
Dr. Yurth's Cannes session, "Confessions of a Longevity Doctor" with Dr. Cynthia Keller, shared a recalibration she says the field needs at the level of clinical thinking itself. She'd made a related case specifically about peptides last year, teaching a room of physicians her own evidence-based framework at the longevitydocs.™ Peptide Mastermind in New York.
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Cannes, "Confessions of a Longevity Doctor": her case that functional medicine's systems-based model isn't granular enough, cellular mechanics, not organ systems, drive disease across the board. Full session in the Cannes 2026 digital replay.
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Peptide Mastermind, "Evidence-Based Peptides Protocols": her framework for replacing endogenous peptides the same way physicians already replace hormones and nutrients. Full session in the Peptide Mastermind digital replay.
Dr. Elizabeth Yurth Co-Founder & Chief Medical Officer, Boulder Longevity Institute · "Confessions of a Longevity Doctor," Cannes 2026
Dr. Yurth spent 30 years as a practicing orthopedist specializing in sports and spine medicine, trained at USC's Keck School of Medicine, UC Irvine, and a Stanford-affiliated sports medicine fellowship, and served as team physician for Stanford and Santa Clara University. In 2006, she co-founded Boulder Longevity Institute, now one of the longest-running longevity clinics in the country, and is fellowship-trained in Anti-Aging, Regenerative, and Cellular Medicine.
She's known for translating molecular biology into clinical frameworks physicians can actually use, approaching peptide therapy as a structured, trackable system that fits into any longevity-focused practice. She brings that same depth of clinical experience to her testimony for the FDA's Pharmacy Compounding Advisory Committee.
Perhaps the biggest mistake I made was functional medicine. We always said that traditional medicine practices a disease focus, and we abandoned that and said we need to look at systems instead. What I want to encourage you to think now is that it isn't a systems approach. We need to look at the cell, because the cell is ultimately responsible for every system. Dr. Elizabeth Yurth, Cannes 2026
Key Takeaways from longevitydocs Cannes 2026
-
Her core argument: functional medicine's systems-based framing was progress, but it still isn't granular enough. Cellular mechanics, not organ systems, dictate disease across the board, if mitochondria are failing, every downstream system follows.
-
Four cellular pathways matter most in practice: the mTOR/AMPK balance (growth signaling vs. endurance signaling), redox balance (oxidative vs. reductive stress), autophagy/mitophagy (cellular cleanup), and mitochondrial biogenesis, which happens through fission of existing mitochondria, not creation of new ones from scratch.
-
Standard labs, read through a cellular lens, reveal pathway-level dysfunction without expensive panels: neutrophil-to-lymphocyte ratio for immune stress, red cell distribution width for autophagy and nutrient status, low (not just high) uric acid for depleted ATP stores, GGT for oxidative stress, and creatinine divided by cystatin C as an early sarcopenia signal.
-
She sorts patients into three buckets: already sick (bucket 1); clean-looking labs with early, silent cellular failure roughly a decade out from bucket 1 (bucket 2, the group she says is most commonly missed by both conventional and functional medicine); and genuinely well (bucket 3). Catching bucket 2 correctly, she argues, is where the field has the most leverage.
-
Several cheap, already-approved drugs are underused for their cellular effects: low-dose telmisartan as a PPAR-gamma agonist to support mitochondrial function, and low-dose daily tadalafil for nitric oxide and energy signaling, both, she notes, safe to a physician's license because they're already FDA-approved.
-
Hormone optimization should generally come before ordering more advanced testing, since correcting a hormone panel changes a large share of downstream labs.
-
Her closing point: purpose may be the single strongest predictor of healthy aging in her practice, stronger than any biomarker, and she argued the field should start screening for it as a literal fourth vital sign.
Mentioned Boulder Longevity Institute · Dr. Cynthia Keller · mTOR/AMPK pathway · autophagy · mitochondrial biogenesis · systemic immune index · red cell distribution width · telmisartan · tadalafil · TMAO
Dr. Cynthia Keller Physician, Centered in Wellness · Co-Presenter, "Confessions of a Longevity Doctor," Cannes 2026
Dr. Keller co-led the Cannes session with Dr. Yurth, bringing her own two decades of clinical experience to the same cellular medicine lens. We are also proud to have her as a Certified longevitydocs.™ CLD Faculty Member.
Key Takeaways
-
Dr. Keller's reframe on TMAO: it's not fundamentally a cardiac marker. It's a signal of gut dysbiosis that does its damage at the cellular level, activating the NLRP3 inflammasome, dysregulating mitochondria in the cardiovascular endothelial lining, and driving mTOR activity in macrophages, before any of that shows up as cardiovascular risk.
-
Her confession: early in practice she reached for whatever was newest and most exciting, exosomes among them, before recognizing that advanced therapeutics can't help a patient whose fundamental cellular mechanics, mitochondria, antioxidant status, metabolism, are already broken.
-
Her clinical focus centers on KPV, which she uses for autoimmune and gut-health inflammation specifically, and which is one of the four peptides the FDA's PCAC voted to recommend for the 503A Bulks List.
Mentioned Centered in Wellness · TMAO · NLRP3 inflammasome · KPV · gut dysbiosis · exosomes
Dr. Elizabeth Yurth's Take on the Future of Peptides
By the time Dr. Yurth reached the microphone at the PCAC hearing, she wasn't lecturing on cellular pathways anymore. She was there as the same physician who'd spent two decades treating patients with these exact therapies, testifying on BPC-157 specifically before the committee that would go on to recommend it hours later.
That's not a data point that shows up in an 8-6 tally. It's a physician putting her name and her patients' stories into the public record, in front of the committee that would go on to recommend BPC-157 for the 503A Bulks List a few hours later.
That authority didn't start at the hearing table. Dr. Yurth is defining evidence-based peptide therapy for physicians. At the longevitydocs.™ Peptide Mastermind in New York last year, she showed a room of physicians how peptides can be used proactively, sequentially, and seasonally. Co-founder of Boulder Longevity Institute, she's known for translating molecular biology into clinical frameworks physicians can actually use, approaching peptide therapy as a structured, trackable system that fits into any longevity-focused practice. She brings that same depth of clinical experience to advocate for peptides, on stage and in front of the FDA committee that would go on to vote on them.
Key Takeaways from the longevitydocs.™ Peptide Mastermind
-
Her starting premise: growth hormone/IGF-1, thymosin alpha-1, thymosin beta-4, epithalon, and BPC-157 are all endogenous peptides that decline with age, the same logic already applied to replacing hormones and micronutrients should apply to replacing them.
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She's openly skeptical of "research-grade" peptides and recommends sourcing only from trusted compounding pharmacies. She's candid that the human evidence base is thin for most peptides, with real approval-level data existing mainly for thymosin alpha-1 (an approved drug in other countries), thymosin beta-4 (approved as an eye drop), and SS-31/elamipretide (FDA-approved for Barth syndrome).
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Her central framework is seasonal, or "circannual," cycling: dosing peptides in rhythm with the body's natural annual hormone cycles, since testosterone, growth hormone, and thyroid all naturally fluctuate by season, instead of running them continuously year-round.
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Winter is a repair window, not a growth one: growth hormone secretagogues taper off in step with the body's natural seasonal decline, SS-31 supports mitochondrial repair, and a roughly 10-day epithalon course timed to the winter solstice resets circadian rhythm.
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Spring is the anabolic surge, when growth hormone receptor sensitivity rises: secretagogue doses go up, thymosin beta-4 is added to support tissue and stem-cell repair, and BPC-157 continues.
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Summer eases back toward maintenance and a second epithalon course marks the summer solstice; autumn shifts to immune prep and metabolic priming for winter, with thymosin alpha-1 timed ahead of vaccine season and MOTS-c supporting mitochondrial function and insulin sensitivity.
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Her practical case for the model: running two or three peptides at a time instead of stacking everything is more affordable for patients and gives four natural checkpoints a year, at each solstice and equinox, to recheck labs and counsel on diet, sleep, and exercise.
Mentioned Boulder Longevity Institute · BPC-157 · thymosin alpha-1 · thymosin beta-4 · epithalon · GHK-Cu · SS-31 (elamipretide) · MOTS-c · seasonal peptide cycling
Shouldn't we be thinking about peptides just like we think about hormones and nutrients? Shouldn't we be replacing the endogenous peptides that my body makes when I'm young that I can't make anymore? No kind of magical pill is going to do it, but I can give them back. Dr. Elizabeth Yurth, longevitydocs Peptide Mastermind
Watch: Dr. Elizabeth Yurth's clinical take on BPC-157, recorded at her "Evidence-Based Peptides Protocols" session for the longevitydocs™ Peptide Mastermind. Watch the full digital replay.
Put the week together and the throughline is the same one this piece opened with. Dr. Egler built the research case for where GLP-1s and peptides are headed. Dr. Starbuck explained the mechanism from the inside, then cast an actual vote. Dr. Yurth turned two decades of clinical experience into testimony a federal committee heard before it voted. Three physicians, one pivotal week for the field, and all three call this community home, for this we are honored.
Stay Ahead of the Field: Join the Next Physician-Only longevitydocs.™ Mastermind: Skin, Bone & Muscle, October 24 in NYC
The next chance to get in the room live with your people is the Skin, Bone & Muscle Mastermind. Learnings you can put immediately into practice, the leading edge of longevity care shared on stage, and a community you can call home. Secure your seat for October 24, 2026 in New York City.
A Pivotal Week for Peptides and the longevitydocs.™ Community
A Pivotal Week for Peptides and the longevitydocs.™ Community
At Cannes 2026, longevitydocs.™ member physicians previewed this topic on stage, weeks before the FDA's Pharmacy Compounding Advisory Committee voted. One sits on the committee. Another testified in front of it and stood on stage advocating at last year's Peptides Mastermind. This is a community of experts in action and we celebrate them.
This week, two longevitydocs.™ physicians were in the room where the FDA decided the future of peptide compounding. One sits on the committee that cast the vote. The other has an evidence-based peptide framework of her own, and took the microphone to testify for it.
At Cannes 2026 (June 8-11), Dr. Jeffrey Egler, Noom's Chief Medical Officer, Noom CEO Geoff Cook, and Dr. Joshua Starbuck previewed exactly the conversation that was coming, in their panel titled "The GLP-1 & Peptide Tsunami." Dr. Egler shared new research on GLP-1 microdosing and its psychosocial effects, and Dr. Starbuck, moderating the panel, used his closing minutes to walk the room through what an eventual FDA peptide vote would and would not mean. While Dr. Elizabeth Yurth's Cannes session, "Confessions of a Longevity Doctor" with Dr. Cynthia Keller, focused on cellular medicine, she shared her deep knowledge of peptides in last year's longevitydocs.™ Peptide Mastermind. This week, she was the one standing at the microphone testifying before the very committee that Dr. Starbuck sits on.
On July 23-24, the FDA's Pharmacy Compounding Advisory Committee (PCAC) met to vote on the near-term future of compounded peptide therapy, and neither Dr. Starbuck nor Dr. Yurth was speculating from the outside back in June. Dr. Starbuck sits on that committee as a voting member, appointed for a term running through 2030 (see his official FDA committee CV and the current PCAC roster). Dr. Yurth testified before it directly, on BPC-157 specifically, one of the physician voices the committee heard before it cast its vote, per Dr. Starbuck's own account of the hearing.
As a community, longevitydocs.™ physicians are coming together to stay at the forefront of peptide understanding in practice, together. We are humbled to have such respected minds in longevity medicine as part of this community.
FDA PCAC Vote: BPC-157, KPV, TB-500, and MOTS-c Recommended for the 503A Bulks List
On Day 1 of the meeting, the committee voted to recommend BPC-157, KPV, and TB-500 for the 503A Bulk Drug Substances List, 8 to 6 with one abstention on each, and MOTS-c by a narrower 7-5 margin with two abstentions, all four against the recommendation of FDA's own scientific review staff, who had flagged unresolved questions about product characterization and gaps in the safety and efficacy data (FDA Law Blog's report from the meeting; Regulatory Focus). As of publishing, the vote is a recommendation only. It still requires FDA sign-off, and the full path to an official rule change, category reclassification followed by notice-and-comment rulemaking, typically runs several months to a year.
Dr. Starbuck laid out exactly this mechanism at Cannes, before any of it was confirmed:
He also drew a distinction that keeps getting lost in the noise: a recommendation to the Bulks List is not the same thing as a Category 1 designation, and the two mechanisms carry very different weight. And he flagged a detail worth remembering for anyone vetting a sourcing partner: 503B compounding pharmacies are federally regulated by the FDA, while 503A pharmacies are state-governed, with only a handful of states, Florida among them, enforcing materially tighter oversight of the manufacturing process.
That regulatory explainer came at the close of a longer panel, "The GLP-1 & Peptide Tsunami," moderated by Dr. Starbuck alongside Noom CEO Geoff Cook and Noom Chief Medical Officer Dr. Jeffrey Egler. The bulk of the session belonged to Egler and Cook, walking through where Noom's clinical research on GLP-1 therapy actually stands.
Dr. Jeffrey Egler Chief Medical Officer, Noom · Panelist, "The GLP-1 & Peptide Tsunami," Cannes 2026, with Geoff Cook (CEO, Noom) and Dr. Joshua Starbuck (Moderator)Egler is double board-certified in Family Medicine and Lifestyle Medicine, with additional training in Functional Medicine and a master's degree in Spiritual Psychology. Before joining Noom as Chief Medical Officer, he was Medical Director at Next Health, held clinical leadership roles at Adventist Health and Parsley Health, and served as an Assistant Clinical Professor of Family Medicine at USC after an academic medicine fellowship at UCLA.
Key Takeaways
Noom's core thesis is that behavior change, not the molecule alone, determines whether GLP-1 gains hold; the biggest failure mode he sees isn't access to the drug, it's people not sustaining results after stopping it.
Noom's microdosing research (submitted for peer-reviewed publication) compared roughly 7,000-8,000 patients on a standard GLP-1 program to nearly 3,000 on a microdose protocol (up to about 33% of the standard maintenance dose): 8.3% weight loss at 16 weeks in the microdose cohort versus 8.6% in the standard cohort, over 95% of the full benefit, alongside a 29% reduction in side effects overall and up to 34% in matched-cohort analysis for GI-specific side effects.
A psychosocial survey of 5,000 GLP-1 users (2,500 on Noom's program, 2,500 using GLP-1s elsewhere) found a 68% increase in flourishing and joy measures, directly contradicting the anhedonia many clinicians worry about, and more than 90% of respondents attributed broader healthy habit changes, not just eating less, to the medication.
88% of surveyed users reported greater self-efficacy, and Noom is running an fMRI study with Penn examining whether reduced food noise on GLP-1s translates into broader self-control, not just less interest in eating.
At the one-year mark, patients who stayed engaged with Noom's companion app were twice as likely to develop interest in broader metabolic health, beyond the weight loss they originally came in for.
Egler was direct about where Noom stands on peptides: the company is watching the compounding space closely but is deliberately staying out of the gray market, wanting any expansion into peptides grounded in the best available safety and efficacy data rather than speed to market.
Mentioned Noom · Geoff Cook · GLP-1 microdosing · ApoB · lipoprotein(a) · Penn fMRI study
Dr. Joshua Starbuck Owner, Founder & Physician, Makena Health · FDA Pharmacy Compounding Advisory Committee · Moderator, "The GLP-1 & Peptide Tsunami," Cannes 2026Dr. Starbuck is a board-certified internist and IFMCP-certified physician who founded Makena Health in Wailea, Hawaii in 2021, after five years as a hospitalist at Maui Memorial Medical Center. In April 2026, he was appointed to a four-year term on the FDA's Pharmacy Compounding Advisory Committee, representing internal medicine expertise. At Cannes, he stepped in at the last minute to moderate this panel after its original moderator, Dr. Steven Murphy, was unable to attend, and used his closing minutes to bring his own regulatory and clinical perspective to the room.
Key Takeaways
The July PCAC vote is a recommendation to add specific peptides to the 503A Bulk Drug Substances List, a different and separate mechanism from an FDA Category 1 designation.
A committee recommendation triggers an open hearing period that can run three to twelve months before anything becomes official; claims that peptides would be broadly legal to compound by August were circulating and are false.
503B compounding pharmacies are federally regulated by the FDA; 503A pharmacies are state-governed, and oversight quality varies significantly by state, Florida enforces tighter scrutiny than most.
Starbuck shared his own n=1 experience: chronic bilateral knee pain in his 50s resolved on one side with targeted supplementation, but the other persisted until two weeks into microdosed GLP-1 therapy (0.2-0.3mg), after which it resolved completely, consistent with emerging data on GLP-1 activity and joint-cartilage cytokine pathways.
His closing argument: optimism about peptide science should not come without discipline. Peptides are tools for informed, responsible clinicians, not a replacement for foundational lifestyle work, and the field is not immune to regulatory scrutiny when it moves faster than its evidence base.
With the FDA's public comment docket open ahead of the July hearing, Dr. Starbuck urged physicians with real clinical experience or outcome data to submit comments directly, calling it a rare moment where physician voices could actually shape the regulatory outcome.
Mentioned FDA Pharmacy Compounding Advisory Committee · 503A / 503B compounding pharmacies · BPC-157 · TB-500 · KPV · MOTS-c · Makena Health · Dr. Steven Murphy
Dr. Elizabeth Yurth: From the Stage to the FDA Hearing Room
Dr. Yurth's Cannes session, "Confessions of a Longevity Doctor" with Dr. Cynthia Keller, shared a recalibration she says the field needs at the level of clinical thinking itself. She'd made a related case specifically about peptides last year, teaching a room of physicians her own evidence-based framework at the longevitydocs.™ Peptide Mastermind in New York.
-
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Dr. Elizabeth Yurth Co-Founder & Chief Medical Officer, Boulder Longevity Institute · "Confessions of a Longevity Doctor," Cannes 2026Cannes, "Confessions of a Longevity Doctor": her case that functional medicine's systems-based model isn't granular enough, cellular mechanics, not organ systems, drive disease across the board. Full session in the Cannes 2026 digital replay.
Peptide Mastermind, "Evidence-Based Peptides Protocols": her framework for replacing endogenous peptides the same way physicians already replace hormones and nutrients. Full session in the Peptide Mastermind digital replay.
Dr. Yurth spent 30 years as a practicing orthopedist specializing in sports and spine medicine, trained at USC's Keck School of Medicine, UC Irvine, and a Stanford-affiliated sports medicine fellowship, and served as team physician for Stanford and Santa Clara University. In 2006, she co-founded Boulder Longevity Institute, now one of the longest-running longevity clinics in the country, and is fellowship-trained in Anti-Aging, Regenerative, and Cellular Medicine.
She's known for translating molecular biology into clinical frameworks physicians can actually use, approaching peptide therapy as a structured, trackable system that fits into any longevity-focused practice. She brings that same depth of clinical experience to her testimony for the FDA's Pharmacy Compounding Advisory Committee.
Key Takeaways from longevitydocs Cannes 2026
Her core argument: functional medicine's systems-based framing was progress, but it still isn't granular enough. Cellular mechanics, not organ systems, dictate disease across the board, if mitochondria are failing, every downstream system follows.
Four cellular pathways matter most in practice: the mTOR/AMPK balance (growth signaling vs. endurance signaling), redox balance (oxidative vs. reductive stress), autophagy/mitophagy (cellular cleanup), and mitochondrial biogenesis, which happens through fission of existing mitochondria, not creation of new ones from scratch.
Standard labs, read through a cellular lens, reveal pathway-level dysfunction without expensive panels: neutrophil-to-lymphocyte ratio for immune stress, red cell distribution width for autophagy and nutrient status, low (not just high) uric acid for depleted ATP stores, GGT for oxidative stress, and creatinine divided by cystatin C as an early sarcopenia signal.
She sorts patients into three buckets: already sick (bucket 1); clean-looking labs with early, silent cellular failure roughly a decade out from bucket 1 (bucket 2, the group she says is most commonly missed by both conventional and functional medicine); and genuinely well (bucket 3). Catching bucket 2 correctly, she argues, is where the field has the most leverage.
Several cheap, already-approved drugs are underused for their cellular effects: low-dose telmisartan as a PPAR-gamma agonist to support mitochondrial function, and low-dose daily tadalafil for nitric oxide and energy signaling, both, she notes, safe to a physician's license because they're already FDA-approved.
Hormone optimization should generally come before ordering more advanced testing, since correcting a hormone panel changes a large share of downstream labs.
Her closing point: purpose may be the single strongest predictor of healthy aging in her practice, stronger than any biomarker, and she argued the field should start screening for it as a literal fourth vital sign.
Mentioned Boulder Longevity Institute · Dr. Cynthia Keller · mTOR/AMPK pathway · autophagy · mitochondrial biogenesis · systemic immune index · red cell distribution width · telmisartan · tadalafil · TMAO
Dr. Cynthia Keller Physician, Centered in Wellness · Co-Presenter, "Confessions of a Longevity Doctor," Cannes 2026Dr. Keller co-led the Cannes session with Dr. Yurth, bringing her own two decades of clinical experience to the same cellular medicine lens. We are also proud to have her as a Certified longevitydocs.™ CLD Faculty Member.
Key Takeaways
Dr. Keller's reframe on TMAO: it's not fundamentally a cardiac marker. It's a signal of gut dysbiosis that does its damage at the cellular level, activating the NLRP3 inflammasome, dysregulating mitochondria in the cardiovascular endothelial lining, and driving mTOR activity in macrophages, before any of that shows up as cardiovascular risk.
Her confession: early in practice she reached for whatever was newest and most exciting, exosomes among them, before recognizing that advanced therapeutics can't help a patient whose fundamental cellular mechanics, mitochondria, antioxidant status, metabolism, are already broken.
Her clinical focus centers on KPV, which she uses for autoimmune and gut-health inflammation specifically, and which is one of the four peptides the FDA's PCAC voted to recommend for the 503A Bulks List.
Mentioned Centered in Wellness · TMAO · NLRP3 inflammasome · KPV · gut dysbiosis · exosomes
Dr. Elizabeth Yurth's Take on the Future of Peptides
By the time Dr. Yurth reached the microphone at the PCAC hearing, she wasn't lecturing on cellular pathways anymore. She was there as the same physician who'd spent two decades treating patients with these exact therapies, testifying on BPC-157 specifically before the committee that would go on to recommend it hours later.
That's not a data point that shows up in an 8-6 tally. It's a physician putting her name and her patients' stories into the public record, in front of the committee that would go on to recommend BPC-157 for the 503A Bulks List a few hours later.
That authority didn't start at the hearing table. Dr. Yurth is defining evidence-based peptide therapy for physicians. At the longevitydocs.™ Peptide Mastermind in New York last year, she showed a room of physicians how peptides can be used proactively, sequentially, and seasonally. Co-founder of Boulder Longevity Institute, she's known for translating molecular biology into clinical frameworks physicians can actually use, approaching peptide therapy as a structured, trackable system that fits into any longevity-focused practice. She brings that same depth of clinical experience to advocate for peptides, on stage and in front of the FDA committee that would go on to vote on them.
Key Takeaways from the longevitydocs.™ Peptide Mastermind
Her starting premise: growth hormone/IGF-1, thymosin alpha-1, thymosin beta-4, epithalon, and BPC-157 are all endogenous peptides that decline with age, the same logic already applied to replacing hormones and micronutrients should apply to replacing them.
She's openly skeptical of "research-grade" peptides and recommends sourcing only from trusted compounding pharmacies. She's candid that the human evidence base is thin for most peptides, with real approval-level data existing mainly for thymosin alpha-1 (an approved drug in other countries), thymosin beta-4 (approved as an eye drop), and SS-31/elamipretide (FDA-approved for Barth syndrome).
Her central framework is seasonal, or "circannual," cycling: dosing peptides in rhythm with the body's natural annual hormone cycles, since testosterone, growth hormone, and thyroid all naturally fluctuate by season, instead of running them continuously year-round.
Winter is a repair window, not a growth one: growth hormone secretagogues taper off in step with the body's natural seasonal decline, SS-31 supports mitochondrial repair, and a roughly 10-day epithalon course timed to the winter solstice resets circadian rhythm.
Spring is the anabolic surge, when growth hormone receptor sensitivity rises: secretagogue doses go up, thymosin beta-4 is added to support tissue and stem-cell repair, and BPC-157 continues.
Summer eases back toward maintenance and a second epithalon course marks the summer solstice; autumn shifts to immune prep and metabolic priming for winter, with thymosin alpha-1 timed ahead of vaccine season and MOTS-c supporting mitochondrial function and insulin sensitivity.
Her practical case for the model: running two or three peptides at a time instead of stacking everything is more affordable for patients and gives four natural checkpoints a year, at each solstice and equinox, to recheck labs and counsel on diet, sleep, and exercise.
Mentioned Boulder Longevity Institute · BPC-157 · thymosin alpha-1 · thymosin beta-4 · epithalon · GHK-Cu · SS-31 (elamipretide) · MOTS-c · seasonal peptide cycling
Put the week together and the throughline is the same one this piece opened with. Dr. Egler built the research case for where GLP-1s and peptides are headed. Dr. Starbuck explained the mechanism from the inside, then cast an actual vote. Dr. Yurth turned two decades of clinical experience into testimony a federal committee heard before it voted. Three physicians, one pivotal week for the field, and all three call this community home, for this we are honored.
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